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LIMITATIONS ON SELECTION OF SAMPLING PERIOD 
The sampling period is limited by the number of DMA cycles allocated to an audio channel. 

Each  audio  channel  is  allocated  one  DMA  slot  per  horizontal  scan  line  of  the  screen 
display. An audio channel can retrieve two data samples during each horizontal scan line. 
The following calculation gives the maximum sampling rate in samples per second. 

 

                2 samples/line * 262.5 frames/frame * 59.94 frames/second 
              = 31,469 samples/second 

 

The Figure of 31,469 is a theoretical maximum. In order to save buffers, the hardware is 
designed  to  handle  28,867  samples/second.  The  system  timing  interval  is  279.365 
nanoseconds, or .279365 microseconds.  The maximum sampling rate of 28,867 samples 

per second is 34.642 microseconds per sample (1/28,867 = .000034642). The formula for 
calculating the sampling period is: 

 

                sample interval     clock constant

 

Period value  = ---------------  =  --------------

 

                clock interval      samples per second

 

 

Thus, the minimum  period  value  is  derived  by dividing 34.642 microseconds  per sample 

by the number of microseconds per interval: 

 

                 34.642 microseconds/sample

 

Maximum period = -------------------------- = 124 timing intervals/sample

 

                 0.279365 microseconds/interval

 

 

or: 

                 3,579,545 ticks/second

 

Minimum period = ---------------------- =124 ticks/sample

 

                  28,867 samples/second

 

 

Therefore, a value of at least 124 must be written into the period register to assure that 
the audio system DMA will be able to retrieve the next data sample. If the period value is 
below 124, by the time the cycle count has reached 0, the audio DMA will not have had 

enough time to retrieve the next data sample and the previous sample will be reused. 
 
28,867  samples/second  is  also  the  maximum  sampling  rate  for  PAL  systems.  Thus,  for 

PAL systems, a value of at least 123 ticks/sample must be written into the period register. 

 

                  CLOCK VALUES

 

                   NTSC   PAL      UNITS

 

 

Clock Constant   3579545 3546895   ticks per second

 

Clock Interval  0.279365 0.281937  microseconds per interval

 

 

                         

 

 
 
 
 
 
 
 
 
 
 
 
 
 

- 138 Audio Hardware -

 

Содержание Amiga A1000

Страница 1: ...AMIGA HARDWARE REFERENCE MANUAL 1992 Commodore Business Machines Amiga 1200 PAL...

Страница 2: ...HES 25 Starting and Stopping the Copper 25 STARTING THE COPPER AFTER RESET 25 STOPPING THE COPPER 26 Advanced Topics 27 THE SKIP INSTRUCTION 27 COPPER LOOPS AND BRANCHES AND COMPARISON ENABLE 28 USING...

Страница 3: ...ESOLUTION MODE 88 COLOR SELECTION IN HOLD AND MODIFY MODE 90 COLOR SELECTION IN HIGH RESOLUTION MODE 90 Chapter 4 SPRITE HARDWARE 93 Introduction 93 ABOUT THIS CHAPTER 94 Forming a Sprite 94 SCREEN PO...

Страница 4: ...pter 6 BLITTER HARDWARE 163 Introduction 163 Memory Layout 164 DMA Channels 164 Function Generator 168 DESIGNING THE LF CONTROL BYTE WITH MINTERMS 169 DESIGNING THE LF CONTROL BYTE WITH VENN DIAGRAMS...

Страница 5: ...MITATIONS OF THE KEYBOARD 247 Parallel Input Output Interface 250 Serial Interface 250 INTRODUCTION TO SERIAL CIRCUITRY 250 SETTING THE BAUD RATE 250 SETTING THE RECEIVE MODE 251 CONTENTS OF THE RECEI...

Страница 6: ...s 332 INTERFACE SIGNALS 332 Appendix G AUTOCONFIG 335 Debugging AUTOCONFIG Boards 336 Address Specification Table 337 Appendix H Keyboard 343 Keyboard Communications 344 Keycodes 345 CAPS LOCK Key 345...

Страница 7: ...sition 74 Figure 3 23 Vertical Scrolling 76 Figure 3 24 Horizontal Scrolling 78 Figure 3 25 Memory Picture Larger than the Display Window 79 Figure 3 26 Data for Line 1 Horizontal Scrolling 79 Figure...

Страница 8: ...Plug and Computer Connector 222 Figure 8 2 Mouse Quadrature 224 Figure 8 3 Joystick to Counter Connections 227 Figure 8 4 Typical Paddle Wiring Diagram 229 Figure 8 5 Effects of Resistance on Charging...

Страница 9: ...Table 4 5 Color Registers in Attached Sprites 119 Table 4 6 Color Registers for Single Sprites 127 Table 4 7 Color Registers for Attached Sprites 128 Table 5 1 Sample Audio Data Set for Channel 0 135...

Страница 10: ...use of custom silicon hardware that yields advanced graphics and sound features There are three distinct models that make up the Amiga computer family the A500 A1000 and A2000 Though the models diffe...

Страница 11: ...ble controller ports for mice joysticks light pens paddles or custom controllers o A professional keyboard with numeric keypad 10 function keys and cursor keys A variety of international keyboards are...

Страница 12: ...tal slices each having different video resolutions and color depths beam synchronized interrupt generation for the 68000 and more The co processor can trigger many times per screen in the middle of li...

Страница 13: ...p memory The original custom chips in the Amiga were designed to be able to physically access up to 512K bytes of shared memory The new version of the Agnus custom chip was created which allows the gr...

Страница 14: ...fully integrated video images with computer generated graphics Laser disk input is accepted in the same manner PERIPHERALS Floppy disk storage is provided by a built in 3 5 inch floppy disk drive Disk...

Страница 15: ...the A500 or A1000 but with the added convenience of simple and extensive expandability The 86 pin external connector of the A1000 and A500 is not externally accessible on the A2000 Instead the A2000...

Страница 16: ...f this manual Generally such functions when available will be found in the library device or resource which manages that portion of the Amiga hardware in the multitasking environment The following lis...

Страница 17: ...y the include file label names are very similar to the equivalent hardware register list names with the following typical differences o Address registers which have low word and high word components a...

Страница 18: ...de that calls routines in the F80000 to FFFFFF range These are ROM addresses and the ROM routines WILL move with every OS revision The only supported interface to system ROM code is through the provid...

Страница 19: ...ch is privileged on the 68010 20 30 Use the Exec function GetCC instead of MOVE SR or use the appropriate non privileged instruction as shown below CPU User Mode Super Mode 68000 MOVE SR ea MOVE SR ea...

Страница 20: ...Figure 1 1 Block Diagram for the Amiga Computer Family Introduction 11...

Страница 21: ...12 Introduction...

Страница 22: ...he 68000 to execute program logic it can also directly affect the contents of most of the chip control registers It is a very powerful tool for directing mid screen modifications in graphics displays...

Страница 23: ...and polygon filling As with all the other DMA channels in the Amiga system the Copper can retrieve its instructions only from the chip RAM area of system memory ABOUT THIS CHAPTER In this chapter you...

Страница 24: ...Copper in controlling the blitter can be found in the sections called Control Register and Using the Copper with the Blitter The WAIT and MOVE instructions are described below The SKIP instruction is...

Страница 25: ...egisters It is strongly recommended that you reference all hardware addresses via their defined names in the system include files This will allow you to more easily adapt your software to take advanta...

Страница 26: ...anced Topics section below Bits 14 8 Vertical position compare enable bits called VE Bits 7 1 Horizontal position compare enable bits called HE The following example WAIT instruction waits for scan li...

Страница 27: ...BEAM POSITION The horizontal beam position has a value of 0 to E2 The least significant bit is not used in the comparison so there are 113 positions available for Copper operations This corresponds to...

Страница 28: ...g long and short lines there are also long and short fields interlace only In NTSC the fields are 262 then 263 lines and in PAL 312 313 This alteration of lines fields produces the standard NTSC 4 fie...

Страница 29: ...gnificant data or low 15 bits of the address Therefore you write the 18 bit address by moving one long word to the register whose name ends in H This is because when you write long words with the 6800...

Страница 30: ...urpose registers all of the time some registers only when a special control bit is set to a 1 some registers not at all The registers that the Copper can always affect are numbered 20 through FF inclu...

Страница 31: ...en during the vertical blanking interval so the data will be properly retrieved when the screen display starts again This can be done with a Copper instruction list that does the following WAIT until...

Страница 32: ...value in the beam counter is equal to or greater than the value in the instruction This means for example if you have instructions following each other like this WAIT for position 64 64 MOVE data WAIT...

Страница 33: ...trary 3 Destination register addresses in copper move instructions are offsets from the base address of the custom chips 4 As always hardware manual examples assume that your application has taken ful...

Страница 34: ...r 0180 COLOR00 DC W COLOR01 0FF0 Move yellow into register 0182 COLOR01 DC W COLOR02 00FF Move cyan into register 0184 COLOR02 DC W COLOR03 0F0F Move magenta into register 0186 COLOR03 End Copper list...

Страница 35: ...isplayed screen to be stable STOPPING THE COPPER No stop instruction is provided for the Copper To ensure that it will stop and do nothing until the screen display ends and the program counter starts...

Страница 36: ...WORD IR1 Bit 0 Always set to 1 Bits 15 8 Vertical position called VP Bits 7 1 Horizontal position called HP Skip if the beam counter is equal to or greater than these combined bits bits 15 through 1...

Страница 37: ...all of the bits in the beam counter may be masked If you look at the description of the IR2 second instruction word you will notice that bit 15 is the blitter finished disable bit This bit is not part...

Страница 38: ...set binary 1xxx1111 This is true for both the vertical and the horizontal WAIT instructions To cause the second loop write to the COPJMP2 register The list is put into an infinite wait when VP 255 so...

Страница 39: ...ed lines and one containing the odd numbered lines Figure 2 1 shows how an interlaced display is stored in memory Odd Field Even field time t time t 16 6ms Data in memory _____________ 1 _____________...

Страница 40: ...ontrol the WAIT When the BFD bit is a 0 the logic of the Copper WAIT instruction is modified The Copper will WAIT until the beam counter comparison is true and the blitter has finished The blitter has...

Страница 41: ...P1 VE1 VP1 VE1 08 DA8 RD08 VP0 VE0 VP0 VE0 07 DA7 RD07 HP8 HE8 HP8 HE8 06 DA6 RD06 HP7 HE7 HP7 HE7 05 DAS RD05 HP6 HE6 HP6 HE6 04 DA4 RD04 HPS HES HPS HES 03 DA3 RD03 HP4 HE4 HP4 HE4 02 DA2 RD02 HP3 H...

Страница 42: ...een display consists of two basic parts playfields which are sometimes called backgrounds and sprites which are easily movable graphics objects This chapter describes how to directly access hardware r...

Страница 43: ...S The Amiga produces its video displays with raster display techniques The picture you see on the screen is made up of a series of horizontal video lines displayed one after the other Each horizontal...

Страница 44: ...single picture element the smallest addressable part of a screen display The drawings below show what a pixel is and how pixels form displays _______________________ _ _ The picture is formed from man...

Страница 45: ...elds In the Amiga graphics system you can have up to thirty two different colors in a single playfield using normal display methods You can control the color of each individual pixel in the playfield...

Страница 46: ..._________________ 00001 _______________________ 00010 _______________________ 00011 _______________________ 00100 _______________________ _______________________ 11111 _______________________ Figure 3...

Страница 47: ...al playfield mode FORMING A BASIC PLAYFIELD To get you started this section describes how to directly access hardware registers to form a single basic playfield that is the same size as the video scre...

Страница 48: ...on the resolution you choose The height is either 200 or 400 lines for NTSC 256 or 512 lines for PAL depending upon whether or not you choose interlaced mode BIT PLANES AND COLOR You define playfield...

Страница 49: ...R02 12 bits User defined color number 2 etc etc COLOR31 12 bits User defined color number 31 COLOR00 is always reserved for the background color The background color shows in any area on the display w...

Страница 50: ...W FFF COLOR00 a0 Load white into color register 0 MOVE W 6FE COLOR01 a0 Load sky blue into color register 1 NOTE The color registers are write only Only by looking at the screen can you find out the...

Страница 51: ...yfield is visible Sixth bit plane is used only in dual playfield mode and in hold and modify mode described in the section called Advanced Topics NOTE The bits in the BPLCON0 register cannot be set in...

Страница 52: ...ide To set horizontal resolution mode you write to bit 15 HIRES in register BPLCON0 High resolution modewrite 1 to bit 15 Low resolution modewrite 0 to bit 15 Note that in high resolution mode you can...

Страница 53: ...______________________ Figure 3 5 Interlacing Even though interlaced mode requires a modest amount of extra work in setting registers as you will see later on in this section it provides fine tuning t...

Страница 54: ...ts the following parameters that are also controlled through register BPLCON0 o High resolution mode is enabled o Two bit planes are used o Hold and modify mode is disabled o Single playfield mode is...

Страница 55: ...plane pointer registers BPLxPTH BPLxPTL to point to the starting memory address of each bitplane you are using The starting address is the memory word that contains the bits of the upper left hand co...

Страница 56: ...splay line and a total of 200 display lines each line of the bit plane requires 40 bytes 320 bits divided by 8 bits per byte 40 Multiply the 200 lines times 40 bytes per line to get 8 000 bytes per bi...

Страница 57: ...as one 32 bit address and write to them as one long word You write to the high order word which is the register whose name ends in PTH The example below shows how to set the bit plane pointers Assumi...

Страница 58: ...s where you want the background color and 1 s where you want the color in register 1 The following example code is identical to the last example except the bit plane is filled with FF00FF00 instead of...

Страница 59: ...ize of the display window which is the actual size of the on screen display Adjustment of display window size affects the entire display area including the border and the sprites not just the playfiel...

Страница 60: ...tion is 2C The horizontal and vertical starting positions are the same both for NTSC and for PAL The hardware allows you to specify a starting position before 81 2C but part of the display may not be...

Страница 61: ...ing position which is the lower right hand corner of the display window If you select high resolution or interlaced mode the stopping position does not change Like the starting position it is interpre...

Страница 62: ...The data fetch registers have a four pixel resolution unlike the display window registers which have a one pixel resolution Each position specified is four pixels from the last one Pixel 0 is positio...

Страница 63: ...a followed by another line For the basic playfield where the playfield in memory is the same size as the display window the modulo is zero because the memory area contains exactly the same number of b...

Страница 64: ...umbered bit planes and BPL2MOD for the even numbered bit planes This allows for differing modules for each playfield in dual playfield mode For normal applications both BPL1MOD and BPL2MOD will be the...

Страница 65: ...rned on You turn on bit plane DMA by writing a 1 to bit BPLEN in the DMACON for DMA control register See Chapter 7 System Control Hardware for instructions on setting this register Each time The playf...

Страница 66: ...ode b Specify width in pixels o 320 for low resolution mode o 640 for high resolution mode c Specify color for each pixel o Load desired colors in color table registers o Define color of each pixel in...

Страница 67: ...200 vertical lines for NTSC 256 for PAL Clear bit 2 in BPLCON0 LACE 2 Allocate Memory To calculate data bytes in the total bit planes use the following formula Bytes per line lines in playfield number...

Страница 68: ...e which is located at 21000 Also a Copper list is set up at 20000 This example relies on the include file hw examples i which is found in Appendix J LEA CUSTOM a0 a0 points at custom chip MOVE W 1200...

Страница 69: ...PLCON0 a0 Hires one bit plane interlaced MOVE W 0 BPLCON1 a0 Horizontal scroll value 0 MOVE W 80 BPL1MOD a0 Modulo 80 for odd bit planes MOVE W 80 BPL2MOD a0 Ditto for even bit planes MOVE W 003C DDFS...

Страница 70: ...to 20000 This keeps the long and short frames in the right relationship to each other VLOOP MOVE W INTREQR a0 d0 Read interrupt requests AND W 0020 d0 Mask off all but vertical blank BEQ VLOOP Loop un...

Страница 71: ...set a bit to activate dual playfield mode Figure 3 12 shows a dual playfield display In Figure 3 12 one of the colors in each playfield is transparent color 0 in playfield 1 and color 8 in playfield 2...

Страница 72: ...Figure 3 12 A dual Playfield display Playfield Hardware 63...

Страница 73: ...4 1 ________ _ 2 ________ _ _ 3 _ 4 __________ __________ __________ __________ 5 1 ________ _ 2 ________ _ _ 3 ________ _ _ 4 _ 5 __________ __________ __________ __________ 6 1 ________ _ 2 ________...

Страница 74: ...ion Mode PLAYFIELD 1 Bit Color Combination Selected 000 Transparent mode 001 COLOR1 010 COLOR2 011 COLOR3 100 COLOR4 101 COLORS 110 COLOR6 111 COLOR7 The hardware interprets color numbers for playfiel...

Страница 75: ...TY AND CONTROL Either playfield 1 or 2 may have priority that is either one may be displayed in front of the other Playfield 1 normally has priority The bit known as PF2PRI bit 6 in register BPLCON2 i...

Страница 76: ...ster BPLCON0 selects dual playfield mode Selecting dual playfield mode changes both the way the hardware groups the bit planes for color interpretation all odd numbered bit planes are grouped together...

Страница 77: ...following ways from displaying the basic playfields described up to now o If the big picture in memory is larger than the display window you must respecify the modules The modulo must be some value ot...

Страница 78: ...eftmost Next Word Next Word Last Display Display Word Word Screen data fetch stops DDFSTOP for each horizontal line after the last word on the line has been fetched Figure 3 15 Data Fetch for the Firs...

Страница 79: ...xt Word Next Word Last Display Display Word Word Figure 3 17 Data Layout for First Line Right Half of Big Picture Now the bit plane pointers contain the value START 80 The modulo 40 is added to the po...

Страница 80: ...t planes it requires 80 200 2 32 000 bytes of memory Recall that this is the memory requirement for the playfield alone You need more memory for any sprites animation audio or application programs you...

Страница 81: ...NTSC ____________262 Figure 3 20 Display Window Vertical Starting Position Recall that you select the values for the starting position as if the display were in low resolution non interlaced mode Kee...

Страница 82: ...P contains both coordinates known as HSTOP and VSTOP See the notes in the Forming a Basic Playfield section for instructions on setting these registers FULL SCREEN AREA 0 255 361 HSTOP of DISPLAY WIND...

Страница 83: ...y the restrictions are simple No data can be displayed in the vertical blanking area The following Table shows the allowable vertical display area Table 3 13 Maximum Allowable Vertical Screen Video Ve...

Страница 84: ...for vertical scrolling is progressively increase or decrease the starting address for the bit plane pointers by the size of a horizontal line in the playfield This has the effect of showing a lower o...

Страница 85: ...n in interlace Figure 3 23 Vertical Scrolling To set up a playfield for vertical scrolling you need to form bit planes tall enough to allow for the amount of scrolling you want write software to calcu...

Страница 86: ...planes wide enough to allow for the scrolling you need o Set the data fetch registers to correctly place each horizontal line including the extra word on the screen o Set the delay bits o Set the mod...

Страница 87: ...Figure 3 24 Horizontal Scrolling 78 playfield hardware...

Страница 88: ...d Next Word Last Display display word word Figure 3 26 Data for Line 1 Horizontal Scrolling At this point the bit plane pointers contain the value START 42 Adding the modulo of 38 gives the correct st...

Страница 89: ...CUSTOM SCROLLED PLAYFIELD SUMMARY The steps for defining a scrolled playfield are the same as those for defining the basic playfield except for the following steps o Defining the data fetch Fetch one...

Страница 90: ...he hold and modify mode allows very fine gradients of color or shading to be produced on the screen For example you might draw a set of 16 vases each a different color using all 16 colors in the color...

Страница 91: ...s active The following example code generates a six bit plane display with hold and modify mode turned on All 32 color registers are loaded with black to prove that the colors are being generated by h...

Страница 92: ...COPPERL pc a2 Point a2 at Copper list image CLOOP MOVE L a2 a1 Move a long word CMPI L FFFFFFFE a2 Check for end of Copper list BNE CLOOP Loop until entire Cop list moved Point Copper at Copper list M...

Страница 93: ...external video source For more information see the instructions furnished with the optional board SUMMARY OF PLAYFIELD REGISTERS This section summarizes the registers used in this chapter and the mean...

Страница 94: ...nd modify enable 1 hold and modify enabled 0 hold and modify disabled Bits 14 13 12 BPU2 BPU1 BPU0 Number of bit planes used 000 only a background color 001 1 bit plane PLANE 1 010 2 bit planes PLANES...

Страница 95: ...de Bits 1 0 not used DDFSTOP Data fetch Stop Ending position for data fetch Bits 15 8 not used Bits 7 2 pixel position H8 H3 Bit H3 only respected in HiRes Mode Bits 1 0 not used BPLxPTH Bit plane Poi...

Страница 96: ...OF COLOR SELECTION This section contains summaries of playfield color selection including color register contents example colors and the differences in color selection in high resolution and low resol...

Страница 97: ...F Bright blue FB0 Golden orange 06D Dark blue FD0 Cadmium yellow 91F Purple FF0 Lemon yellow ClF Violet BF0 Lime green FlF Magenta 8E0 Light green FAC Pink 0F0 Green DB9 Tan 2C0 Dark green C80 Brown 0...

Страница 98: ...6 00111 0111 111 7 Playfield 2 Bit planes 6 4 2 01000 1000 000 8 01001 1001 001 9 01010 1010 010 10 01011 1011 011 11 01100 1100 100 12 01101 1101 101 13 01110 1110 110 14 01111 1111 111 15 10000 16 1...

Страница 99: ...lane 5 Result 0 0 Normal operation use color register itself 0 1 Hold green and red B Bit plane 4 1 contents 0 Hold green and blue R Bit plane 4 1 contents Hold blue and red G Bit plane 4 1 contents C...

Страница 100: ...Bit planes 3 1 0000 00 0 0001 01 1 0010 10 2 0011 11 3 0100 4 0101 NOT USED 5 0110 IN THIS MODE 6 0111 7 Playfield 2 Bit planes 4 2 1000 00 8 1001 01 9 1010 10 10 1011 11 11 1100 12 1101 NOT USED 13...

Страница 101: ...92 Playfield Hardware...

Страница 102: ...animation effects by using the blitter which is described in the chapter called Blitter Hardware Sprites are produced on screen by eight special purpose sprite DMA channels Basic sprites are 16 pixels...

Страница 103: ...ata structure in memory You define a sprite by specifying its characteristics o On screen width of up to 16 pixels o Unlimited height o Any shape o A combination of three colors plus transparent o Any...

Страница 104: ...pixels long Larger or smaller windows can be defined as required but it is recommended that you read the Playfield Hardware chapter before attempting to do so A larger area is actually scanned by the...

Страница 105: ...0 to line 262 for the topmost edge of the sprite In the examples in this chapter an NTSC window with vertical positions from line 44 to line 243 is used This allows the normal display height of 200 l...

Страница 106: ...reen s height or 1 256 of a PAL screen s height This pixel size corresponds to the low resolution and non interlaced modes of the normal full size playfield Sprites however are independent of playfiel...

Страница 107: ...of the sprite Whenever the shape is narrower than the sprite you can control which part of the sprite is used to define the shape This particular shape could also start at any of the pixels from 2 7 i...

Страница 108: ...that particular sprite DMA channel The eight sprites use system color registers 16 31 For purposes of color selection the eight sprites are organized into pairs and each pair uses four of the color r...

Страница 109: ...__ Unused 28 00 _________________________ Sprite 6 or 7 01 _________________________ 10 _________________________ __ 11 _________________________ 31 Figure 4 6 Color Register Assignments If you requi...

Страница 110: ...words contain position and control information and some contain color descriptions To create a sprite s data structure you need to o Write the horizontal and vertical position of the sprite into the f...

Страница 111: ...criptor high word Color bits for line 2 End of data words Two words indicating the next usage of this sprite All memory addresses for sprites are word addresses You will need enough contiguous memory...

Страница 112: ...e 1 N _________________________________ _ Pairs of words G _____ containing color _____ Data describing central information for A _____ lines of this sprite pixel lines D _____________________________...

Страница 113: ...SPRxCTL Bits 15 8 The low eight bits of VSTOP Bit 7 Used in attachment Bits 6 3 Unused make zero Bit 2 The VSTART high bit Bit 1 The VSTOP high bit Bit 0 The HSTART low bit The value VSTOP VSTART def...

Страница 114: ...ine becomes the color descriptor high word In this fashion you translate each line in the sprite into binary 0s and 1s See Figure 4 7 Each of the binary numbers formed by the combination of the two da...

Страница 115: ...c mode In this mode once the sprite DMA channel begins to retrieve and display the data the display continues until the VSTOP position is reached Manual mode is described later on in this chapter The...

Страница 116: ...e 0 pointer These pointers are dynamic they are incremented by the sprite DMA channel to point first to the control words then to the data words and finally to the end of data words After reading in t...

Страница 117: ...ters MOVE W 0008 COLOR00 a0 Background color dark blue MOVE W 0000 COLOR01 a0 Foreground color black MOVE W 0FF0 COLOR17 a0 Color 17 yellow MOVE W 00FF COLOR18 a0 Color 18 cyan MOVE W 0FOF COLORl9 a0...

Страница 118: ...BPL1PTL 1000 DC W SPR0PTH 0002 Sprite 0 pointer 25000 DC W SPR0PTL 5000 DC W SPR1PTH 0003 Sprite 1 pointer 30000 DC W SPR1PTL 0000 DC W SPR2PTH 0003 Sprite 2 pointer 30000 DC W SPR2PTL 0000 DC W SPR3...

Страница 119: ...detect these collisions and exploit this capability for special effects In addition you can use collision detection to keep a moving object within specified on screen boundaries Collision Detection i...

Страница 120: ...TOP to sprite BRA VLOOP Loop forever CREATING ADDITIONAL SPRITES To use additional sprites you must create a data structure for each one and arrange the display as shown in the previous section naming...

Страница 121: ...en you may need to take into consideration their relative video priority that is which sprite appears in front of or behind another Each sprite has a fixed video priority with respect to all the other...

Страница 122: ...9 Figure 4 9 Typical Example of Sprite Reuse In single sprite usage two all zero words are placed at the end of the data structure to stop the DMA channel from retrieving any more data for that partic...

Страница 123: ...____________________________ word must be at ________________________________ least one video _________ line below actual _________ end of preceding _________ usage ________________________________ V...

Страница 124: ...3FFC 0000 DC W 0FF0 0000 DC W 03C0 0000 DC W 0180 0000 DC W 0000 0000 End of sprite data OVERLAPPED SPRITES For more complex or larger moving objects you can overlap sprites Overlapping simply mean th...

Страница 125: ...hed You can create a wider sprite display by placing two sprites next to each other For instance Figure 4 12 shows the spaceship sprite and how it can be made twice as large by using two sprites place...

Страница 126: ...prite creating two sprites of the same size and located at the same position o Set a bit called ATTACH in the second sprite control word The fifteen colors are selected from the full range of color re...

Страница 127: ...e of Spaceship Sprite PIXEL NUMBER 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Line 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Line 2 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0 0 Line 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Line 4 0 0...

Страница 128: ...1 in the data structure for the odd numbered sprite So in this example you set bit 7 in sprite control word 2 in the data structure for sprite 1 When the sprites are moved the Copper list must keep t...

Страница 129: ...ite that is showing a DMA controlled icon near the top of the screen can also be reloaded manually to show a vertical colored bar near the bottom of the screen Sprites can be activated manually even w...

Страница 130: ...ry The shifting and data output does not begin again until the next time this converter is loaded from the data registers Because the video image is produced by an electron beam that is being swept fr...

Страница 131: ..._ Parallel to Sprite serial __ __ serial converter video data ___ _________________ _ _________________ Output to Parallel to video priority serial converter logic _________________ _____ ____________...

Страница 132: ...lue part of SPRxPOS When these values match the system enables the sprite data access The sprite DMA channel examines the contents of VSTOP from SPRxCTL which is the location of the line after the las...

Страница 133: ...splay progresses Therefore pointer registers must be freshly written during the start of the vertical blanking period SPR0PTH and SPR0PTL This pair of registers contains the 32 bit word address of Spr...

Страница 134: ...position for a sprite image bits V7 V0 o Bit 7 is the attach bit This bit is valid only for odd numbered sprites It indicates that sprites 0 1 or 2 3 or 4 5 or 6 7 will for color interpretation be co...

Страница 135: ...TA SPR1DATB data registers for Sprite 1 SPR2DATA SPR2DATB data registers for Sprite 2 SPR3DATA SPR3DATB data registers for Sprite 3 SPR4DATA SPR4DATB data registers for Sprite 4 SPR5DATA SPR5DATB data...

Страница 136: ...ed 01 17 10 18 11 19 2 or 3 00 Not used 01 21 10 22 11 23 4 or 5 00 Not used 01 25 10 26 11 27 6 or 7 00 Not used 01 29 10 30 11 31 Selects transparent mode If the bit combinations from attached sprit...

Страница 137: ...3 1000 24 1001 25 1010 26 1011 27 1100 28 1101 29 1110 30 1111 31 INTERACTIONS AMONG SPRITES AND OTHER OBJECTS Playfields share the display with sprites Chapter 7 System Control Hardware shows how pla...

Страница 138: ...shows you how to directly access the audio hardware to produce sounds The major topics in this chapter are o A brief overview of how a computer produces sound o How to produce simple steady and changi...

Страница 139: ...licators of Microprocessors Rochelle Park New Jersey Hayden 1980 INTRODUCING SOUND GENERATION Sound travels through air to your ear drums as a repeated cycle of air pressure variations or sound waves...

Страница 140: ...as high as that of the first tone and its perceived pitch is twice as high The second parameter that defines a waveform is its amplitude In an electronic circuit amplitude relates to the voltage or cu...

Страница 141: ...s the voltage waveforms to a loudspeaker which translates them into air pressure vibrations that the listener perceives as sound A computer cannot store analog waveform information In computer product...

Страница 142: ...00 0 11 39 100 20 12 75 100 40 13 103 100 60 14 121 100 80 15 127 100 100 16 121 100 80 17 103 100 60 18 75 100 40 19 39 100 20 THE AMIGA SOUND HARDWARE The Amiga has four hardware sound channels You...

Страница 143: ...the waveform and create the sample Table in memory 3 Set registers telling the system where to find the data and the length of the data 4 Select the volume at which the tone is to be played 5 Select...

Страница 144: ...it reads as two bytes of data To use audio channel 0 write the address of audiodata into AUD0LC where the audio data is organized as shown below For simplicity AUDxLC in the Table below stands for the...

Страница 145: ...e location registers WHERE0DATA LEA CUSTOM a0 Base chip address LEA AUDIODATA a1 MOVE L a1 AUDOLCH a0 Put address 32 bits into location register The length of the data is the number of samples in your...

Страница 146: ...by the waveform depends upon its frequency To tell the system what frequency to use you need to specify the sampling period The sampling period specifies the number of system clock ticks or timing in...

Страница 147: ...ck constant Period value clock interval samples per second Thus the minimum period value is derived by dividing 34 642 microseconds per sample by the number of microseconds per interval 34 642 microse...

Страница 148: ...G THE PERIOD VALUE After you have selected the desired interval between data samples you can calculate the value to place in the period register by using the period formula desired interval clock cons...

Страница 149: ...e high quality sound avoiding aliasing distortion you should observe the limitations on period values that are discussed in the section below called Producing Quality Sound For the relationship betwee...

Страница 150: ...he audio channel as shown below BEGINCHAN0 LEA CUSTOM a0 MOVE W DMAF_SETCLR DMAF_AUD0 DMAF_MASTER DMACON a0 STOPPING THE AUDIO DMA You can stop the channel by writing a 0 into the AUDxEN bit at any ti...

Страница 151: ...AEN along with a 1 in the SET CLR bit and a 1 in the position of the AUDxEN bit of the channel or channels you want to start EXAMPLE In this example which gathers together all of the program segments...

Страница 152: ...nnel then stores the values in back up registers Once the original registers have been read by the DMA channel you can change their values without disturbing the operation you started with the origina...

Страница 153: ...as its interaction with the audio DMA system The example assumes that the period volume and length of the data set remains the same for the sine wave and the triangle wave INTERRUPT PROGRAM If wave t...

Страница 154: ...ulate a channel s frequency or amplitude or do both types of modulation on a channel at the same time Amplitude modulation affects the volume of the waveform It is often used to produce vibrato or tre...

Страница 155: ...frequency of channel 1 you set two attach bits bit 0 to modulate the volume and bit 4 to modulate the period When period and volume are both modulated words in the modulator channel s data set are def...

Страница 156: ...attach channel 3 Writing a 1 into channel 3 s modulate bits only disables its audio output Table 5 5 Channel Attachment for Modulation ADKCON REGISTER Bit Name Function 7 ATPER3 Use audio channel 3 t...

Страница 157: ...can avoid thumps by arranging the average amplitude of each wave to be about the same value The average amplitude is the sum of the bytes in the waveform divided by the number of bytes in the wavefor...

Страница 158: ...ere is only one waveform buffer the hardware automatically resets the pointers so no software overhead is used for resetting them The Joining Tones section illustrated how you could join ends of tones...

Страница 159: ...nal Proportionally the digital value used to represent the waveform amplitude will have a lower error As you increase the number of possible sample levels you decrease the relative size of each step a...

Страница 160: ...e of the filter as shown in these calculations 12 4 16KHz 12 4 8KHz Filter response 12 KHz sampling frequency 0 db ____ Diff Sum 4 30 db ____ __ _ ___ _____ _____________________ 05 10 15 20 25 30 KHz...

Страница 161: ...ou may be producing a complex waveform with multiple frequency elements rather than a pure sine wave LOW PASS FILTER The system includes a low pass filter that eliminates aliasing distortion as descri...

Страница 162: ...ossible to create sound by writing audio data one word at a time to the audio output addresses instead of setting up a list of audio data in memory This method of controlling the output is more proces...

Страница 163: ...G 1568 0 1564 5 1572 2 135 133 G 1661 2 1657 2 1666 8 The Table above shows the period values to use with a 16 byte sample to make tones in the second octave above middle C To generate the tones in th...

Страница 164: ...5 7 were generated using the formula shown below To calculate the tone generated with a given sample size and period use Clock Constant 3579545 Frequency 880 8hz Sample Bytes Period 16 Period The clo...

Страница 165: ...26 224 B 123 47 123 74 123 70 214 212 C 130 81 130 68 130 71 202 200 C 138 59 138 44 138 55 190 189 D 146 83 147 18 146 61 180 178 D 155 56 155 36 155 67 170 168 E 164 81 164 50 164 94 160 159 F 174 6...

Страница 166: ...99 13 697 11 151 150 F 739 99 740 80 738 94 143 141 G 783 99 782 24 786 10 135 133 G 830 61 828 60 833 39 Sample size 32 bytes AUDxLEN 16 254 252 A 880 0 880 8 879 7 240 238 A 932 3 932 2 931 4 226 22...

Страница 167: ...66 64 62 60 58 56 54 52 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 128 BYTE SAMPLE 0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 100 104 108 112...

Страница 168: ...61 0 4 129 6 9 60 0 6 28 7 2 59 0 7 27 7 5 58 0 9 26 7 8 57 1 0 25 8 2 56 1 2 24 8 5 55 1 3 23 8 9 54 1 5 22 9 3 53 1 6 21 9 7 52 1 8 20 10 1 51 2 0 19 10 5 50 2 1 18 11 0 49 2 3 17 11 5 48 2 5 16 12...

Страница 169: ...arrives state 010 is entered and the main loop continues until the DMA is turned off The length counter counts down once with each word that comes in When it finishes a DMA restart request goes to Ag...

Страница 170: ...able percntrld Reload period counter from back up latch typically written by processor with AUDxPER can also be written by attach mode percount Count period counter down one latch perfin Period counte...

Страница 171: ...UDxAV AUDxAP AUDxAV no attach stuff or else attach volume Condition for normal DMA and interrupt requests sq2 1 0 The name of the state flip flops MSB to LSB Figure 5 8 Audio State Diagram 162 Audio H...

Страница 172: ...t four megabytes per second It can draw lines at almost a million pixels per second In block move mode the blitter can perform any logical operation on up to three source areas it can shift up to two...

Страница 173: ...C and one destination channel called D Each of these channels has separate address pointer modulo and data registers and an enable bit Two have shift registers and one has a first and last word mask r...

Страница 174: ...d 16 pixels of a single bitplane If this image required sixteen colors four bit planes like this would be required in memory and four copy move operations would be required to completely move the imag...

Страница 175: ...el is added to the address pointer A row is defined by the width stored in BLTSIZE NOTE The modulo values are in bytes not words Since the blitter can only operate on words the least significant bit i...

Страница 176: ...ather than rectangular regions by setting the horizontal or vertical count in BLTSIZE to 1 Because each DMA channel has its own modulo register data can be moved among bitplanes of different widths Th...

Страница 177: ...and the possible values for a single bit from each one A B C D BLTCON0 position MINTERM ___ 0 0 0 0 ABC __ 0 0 1 1 ABC _ _ 0 1 0 2 ABC _ 0 1 1 3 ABC __ 1 0 0 4 ABC _ 1 0 1 5 ABC _ 1 1 0 6 ABC 1 1 1 7...

Страница 178: ...has a higher precedence so AB BC is equal to AB BC Any function can be written as a sum of minterms If we wanted to calculate the function where D is one when the A bit is set and the C bit _ is clear...

Страница 179: ...h the car mask the B DMA channel to fetch the actual car data the C DMA channel to fetch the background and the D DMA channel to write out the new image NOTE We must fetch the destination background b...

Страница 180: ...C0 _ _ D A 0F D AB 30 _ D B CC D AB 0C _ __ D B 33 D AB 03 D C AA D BC 88 _ _ D C 55 D BC 44 _ D AC A0 D BC 22 _ __ D AC 50 D AC 11 _ _ D AC 0A D A B F3 __ _ _ D AC 05 D A B 3F _ D A B FC D A C FS _...

Страница 181: ...erms 7 6 5 and 4 When written as a set of 1s for the selected minterms and 0s for those not selected the value becomes Minterm Number 7 6 5 4 3 2 1 0 Selected Minterms 1 1 1 1 0 0 0 0 F 0 equals F0 2...

Страница 182: ...shifting operation is completely free it requires no more time to execute a blit with shifts than a blit without shifts as opposed to shifting with the 68000 The shift is normally towards the right Th...

Страница 183: ...irst and last word masks When not in use both should be initialized to all ones FFFF NOTE Text fonts on the Amiga are stored in a packed bit map Individual characters from the font are extracted using...

Страница 184: ...___ Source is passed through mask when it is a one otherwise the destination is copied Destination does not change where mask is 0 Figure 6 4 Extracting a Range of Columns To do this we point the B DM...

Страница 185: ...down towards increasing addresses however we run into a problem we overwrite the second row before we get a chance to copy it The blitter has a special mode of operation descending mode that solves th...

Страница 186: ...ion are as follows 1 Use the A DMA channel disabled preloaded with all ones and the appropriate mask and shift values to mask the cookie cut function Use the B channel to fetch the source data the C c...

Страница 187: ...ILL MODE In addition to copying data the blitter can simultaneously perform a fill operation during the copy The fill operation has only one restriction the area to fill must be defined first by drawi...

Страница 188: ...e FCI Bit Bit Is a 0 If the FCI bit is a 1 instead of a 0 the area outside the lines is filled with ls and the area inside the lines is left with 0s in between BEFORE AFTER ____________________ ______...

Страница 189: ...nt the filling stops BLITTER DONE FLAG When the BLTSIZE register is written the blit is started The processor does not stop while the blitter is working though they can both work concurrently and this...

Страница 190: ...t even the first time Use of the ROM kernel function WaitBlit is recommended You should also check the blitter done flag before using results of a blit The blit may not be finished so the data may not...

Страница 191: ...blitter is pipelined This means that rather than performing all of the above operations in one blitter cycle the operations are spread over two blitter cycles Here cycle is used very loosely for simp...

Страница 192: ...l o No competing bus activity o Three word blit o Typical operation involves fetching all sources twice before the first destination becomes available This is due to internal pipelining Care must be t...

Страница 193: ...riptions of the use of these registers and control bits in line drawing mode In line mode the blitter draws a line from one point to another which can be viewed as a vector The direction of the vector...

Страница 194: ...culations have the effect of normalizing our line into octant 0 since we have already informed the blitter of the real octant to use it has no difficulty drawing the line We initialize the A pointer r...

Страница 195: ...o draw the line using exclusive or mode so it can be easily erased by drawing it again the function ABC AC can be used We set the blit height to the length of the line which is dx 1 The width must be...

Страница 196: ...DE 1 BLTCON1 bit OVFLAG 0 BLTCON1 bits 4 2 octant number from Table BLTCON1 bits 15 12 start bit for line texture 0 last significant bit if 4 dy 2 dx 0 then BLTCON1 bit SIGNFLAG 1 else BLTCON1 bit SIG...

Страница 197: ...ht ticks The system clock speed for NTSC Amiga s is 7 16 megahertz PAL Amiga s 7 09 megahertz The clock for the blitter is the system clock To calculate the total time for the blit in microseconds exc...

Страница 198: ...use missed DMA cycles can cause lost data noise in the sound output or on screen interruptions The Copper has the next priority because it has to perform its operations at the same time during each di...

Страница 199: ...Figure 6 9 DMA time slot allocation 190 Blitter hardware...

Страница 200: ...nstruction TAS should never be used in the Amiga the indivisible read modify write cycle that is used only in this instruction will not fit into a DMA memory access slot Average 68000 cycle internal m...

Страница 201: ...l blanking T TIMING CYCLE T 7 4 2 3 1 4 2 3 1 Figure 6 12 Time Slots Used by a High Resolution Display Each horizontal line in a normal full sized display contains 320 pixels in low resolution mode or...

Страница 202: ...the blitter It does not cover the line drawing hardware o The upper left comer shows how the first and last word masks are applied to the incoming A source data When the blit shrinks to one word wide...

Страница 203: ...Figure 6 13 Blitter Block Diagram 194 Blitter Hardware...

Страница 204: ...ts to the right o In descending mode the blitter decrements the pointers subtracts the modules and shifts to the left o Area fill only works correctly in descending mode o Check BLTDONE before writing...

Страница 205: ...es move w DEST BLTCON0 a1 only enable destination First we deal with the smaller blits moveq 3f d1 Mask out mod 64 words and w d0 d1 beq dorest none good do one blit sub l d1 d0 otherwise remove remai...

Страница 206: ...if y x octant is 2 moveq l OCTANT1 LINEMODE d5 otherwise octant is 1 bra lineagain go to the common section ygtx exg d2 d3 X must be greater than Y moveq l OCTANT2 LINEMODE d5 we are in octant 2 bra...

Страница 207: ...and add 1 to height 2 to width btst DMAB_BLTDONE 8 DMACONR al safety check waitblit btst DMAB_BLTDONE 8 DMACONR a1 wait for blitter bne waitblit move w d3 BLTBMOD a1 B mod 4 Y sub w d2 d3 ext l d3 mov...

Страница 208: ...ess the custom registers tst d0 if no words just return beq gone lea DMACONR a2 a3 get the address of dmaconr moveq l DMAB BLTDONE 8 d2 get the bit number BLTDONE btst d2 a3 check to see if we re done...

Страница 209: ...st d2 a3 Check blit done wait2 btst d2 a3 Check again bne wait2 oops not ready loop around inloop move w d3 a4 stuff new word to make vertical move w d1 a5 start the blit subq w 1 d0 is that the last...

Страница 210: ...DUCTION This chapter covers the control hardware of the Amiga system including the following topics o How playfield priorities may be specified relative to the sprites o How collisions between objects...

Страница 211: ...ty may be changed relative to sprites FIXED SPRITE PRIORITIES You cannot change the relative priorities of the sprites They will always appear on the screen with the lower numbered sprites appearing i...

Страница 212: ...your hands represent the four pairs of sprites and two fingers of your other hand represent the two playfields Just as you cannot change the sequence of the four fingers on the one hand neither can yo...

Страница 213: ...E PRIORITY CONTROL REGISTER This register lets you define how objects will pass in front of each other or hide behind each other Normally playfield 1 appears in front of playfield 2 The PF2PRI bit rev...

Страница 214: ...een Here is a sample of possible BPLCON2 register contents that would create something a little unusual BITS 15 7 PF2PRI PF2P2 0 PF1P2 0 VALUE 0s 1 010 000 This will result in a sprite playfield prior...

Страница 215: ...verything is displayed together sprite 0 is more important than playfield 2 but less important 3883 than playfield 1 So even though you can t see the boundary the sprite disappears behind the invisibl...

Страница 216: ...ve using the blitter This is called playfield animation If one playfield is defined as the backdrop or playing area and the other playfield is used to define objects in addition to the sprites you can...

Страница 217: ...sprite 0 or l 4 Odd bit planes to sprite 6 or 7 3 Odd bit planes to sprite 4 or 5 2 Odd bit planes to sprite 2 or 3 1 Odd bit planes to sprite 0 or 1 0 Even bit planes to odd bit planes NOTE The numb...

Страница 218: ...t plane 5 collision 3 MVBP4 Match value for bit plane 4 collision 2 MVBP3 Match value for bit plane 3 collision 1 MVBP2 Match value for bit plane 2 collision 0 MVBP1 Match value for bit plane 1 collis...

Страница 219: ...operations based on the beam position NOTE The Copper is already capable of watching the display position for you and doing certain register based operations automatically Refer to Copper Interrupts...

Страница 220: ...osition bits V7 V0 Bits 7 0 The horizontal position bits H8 H1 Horizontal resolution is 1 160th of the screen width VPOSW Write only Bits same as VPOSR above VHPOSW Write only Bits same as VHPOSR abov...

Страница 221: ...1 have been routed to the expansion connector for use by external hardware for interrupts These are known as the external low and external high level interrupts These interrupt lines are connected to...

Страница 222: ...gisters and how you use them SET AND CLEAR The interrupt registers as well as the DMA control register use a special way of selecting which of the bits are to be set or cleared Bit 15 of these registe...

Страница 223: ...required to perform many different tasks during the vertical blanking interval Among these tasks are the updating of various pointer registers rewriting lists of Copper tasks when necessary and other...

Страница 224: ...1 and 0 respectively This level 4 interrupt signals audio block done When the audio DMA is operating in automatic mode this interrupt occurs when the last word in an audio data stream has been access...

Страница 225: ...t 0 TBE for transmit buffer empty specifies that the output buffer of the UART needs more data and data can now be written into this buffer This bit generates a level 1 interrupt Hardware Exec Softwar...

Страница 226: ...ntrol read only DMACON Direct Memory Access Control write only The contents of this register are shown in Table 7 5 bit on if enabled PROCESSOR ACCESS TO CHIP MEMORY The Amiga chips access chip memory...

Страница 227: ...al priority over the 68000 9 DMAEN DMA enable This is a master DMA enable bit It enables the DMA for all of the channels at bits 8 0 8 BPLEN Bit plane DMA enable 7 COPEN Coprocessor DMA enable 6 BLTEN...

Страница 228: ...he 68000 RESET instruction works much like external reset or power on All memory and AUTOCONFIGTM cards disappear and the ROM image appears at location 00000000 The difference is that the CPU continue...

Страница 229: ...220 System Control Hardware...

Страница 230: ...s the interface hardware through which the Amiga talks to the outside world including the following features o Two multiple purpose mouse joystick light pen control ports o Disk controller for floppy...

Страница 231: ...tors RGB monochrome Nl SC RF modulator video slot CONTROLLER PORT INTERFACE Each Amiga has two nine pin connectors that can be used for input or output with many different kinds of controllers The Fig...

Страница 232: ...so be conFigured as outputs These buttons are optional REGISTERS USED WITH THE CONTROLLER PORT JOY0DAT DFF00A Counter for digital mouse input port 1 JOY1DAT DFF00C Counter for digital mouse input port...

Страница 233: ...decrement when the mouse is moved to the left or up away from you MOUSE QUADRATURE V VQ D1 D0 0 0 1 0 0 1 0 1 1 0 1 1 1 1 0 0 Case 1 Count up ________ ________ ________ ____ V ____ ________ ________...

Страница 234: ...irection Vertical blanking happens once each 1 60th of a second If you read the mouse once each vertical blanking period you will most likely find a count difference from the previous count of less th...

Страница 235: ...t 1 is connected to bit 6 port 2 is connected to bit 7 See the 8520 Appendix for more information A logic state of 1 means switch open A logic state of 0 means switch closed o Button 2 right button on...

Страница 236: ...ret the data once you have read it from these registers The true logic state of the switch data in these registers is 1 switch closed _________________ This is the 1 2 3 4 5 way the pins 6 7 8 9 are n...

Страница 237: ...if the function the button controls is duplicated via the keyboard or another mechanism This button may be read in the same manner as the right mouse button READING PROPORTIONAL CONTROLLERS Each of th...

Страница 238: ...interval During vertical blanking you write a value into an address called POTGO For a standard X Y joystick this value is hex 0001 Writing to this register starts the operation of some special hardw...

Страница 239: ...r cannot overflow within the span of a single screen This allows you to know for certain whether an overflow is indicated by the controller PROPORTIONAL CONTROLLER REGISTERS The following registers ar...

Страница 240: ...al input readings will need to be averaged Port 1 connector ___________________ ________________________ o o o o o POT1Y POT1X POT1DAT o o o o COUNTER COUNTER DFF014 __________ _ ____________ ________...

Страница 241: ...light pen operation are as follows 1 Just as the system exits vertical blank the capture circuitry for the light pen is automatically enabled 2 The video beam starts to create the picture sweeping fro...

Страница 242: ...readings together To enable the light pen input write a 1 into bit 3 of BPLCON0 Once the light pen input is enabled and the light pen issues a trigger signal the value in VPOSR is frozen If no trigge...

Страница 243: ...OLLER PORT The Amiga can read and interpret many different and nonstandard controllers The control lines built into the POTGO register address DFF034 can redefine the functions of some of the controll...

Страница 244: ...his set the proper pin to output and drive the line high set both OUT and DAT to 1 Reading POTINP will produce a 0 if the button is pressed a 1 if it is not The joystick fire buttons can also be confi...

Страница 245: ...ing CIABPRB BFD100 eight output bits for disk selection control and stepping ADKCON DFF09E control bits write only register ADKCONR DFF010 control bits read only register DSKPTH DFF020 DMA pointer 32...

Страница 246: ...Figure 8 8 Chinon Timing diagram cont Interface Hardware 237...

Страница 247: ...rds when this signal is active Some drives will refuse to step others will attempt the step possibly causing alignment damage All new drives must refuse to step outward in this condition PA3 DSKPROT D...

Страница 248: ...is at the outside of the disk This line must be set up before the actual step pulse with a separate write to the register PB0 DSKSTEP Step the heads of the disk This signal must always be used as a q...

Страница 249: ...e address from which or to which the data is to be transferred The lowest bit of the address must be zero and the buffer must be in CHIP memory The value must be written as a single long word to the D...

Страница 250: ...counts down to 0 the transfer stops The recommended method of reading from the disk is to read an entire track into a buffer and then search for the sector s that you want Using the DSKSYNC register...

Страница 251: ...various DMA bits must be true This means the DMAEN bit in DKSLEN and the DSKEN DMAEN bits in DMACON 13 DISKWRITE The disk write bit in DSKLEN is enabled 12 WORDEQUAL Indicates the DISKSYNC register eq...

Страница 252: ...40 ns Value of 10 selects 280 ns Value of 11 selects 560 ns 12 MFMPREC Value of 0 selects GCR Precompensation Value of 1 selects MFM Precompensation 10 WORDSYNC Value of 1 enables synchronizing and st...

Страница 253: ...YNC bit is enabled in ADKCON no data is transferred until a word is found in the input stream that matches the word in the DSKSYNC register On read DMA will start with the following word from the disk...

Страница 254: ...1 microsecond handshake pulse the pulse must be at least 85 microseconds for operation with all models of Amiga keyboards If another keystroke is received before the previous one has been accepted by...

Страница 255: ...ave two more keys that are cut out of larger keys on the USA version These are 30 cut out from the left shift and 2B cut out from the return key RAW KEYCODES 40 5F HEX CODES COMMON TO ALL KEYBOARDS 40...

Страница 256: ...key switch at each intersection see Appendix H for a diagram of the matrix Because of this the keyboard is subject to a phenomenon called phantom keystrokes While this is generally not a problem for...

Страница 257: ...bed are pressed Normally the keyboard will appear to have N key rollover which means that you will run out of fingers before generating a ghost character NOTE Seven keys are not part of the matrix and...

Страница 258: ...Figure 8 9 The Amiga 1000 Keyboard Showing Keycodes in hex Figure 8 10 the Amiga 500 2000 Keyboard showing Keycodes in hex Interface Hardware 249...

Страница 259: ...UCTION TO SERIAL CIRCUITRY The Paula custom chip contains a Universal Asynchronous Receiver Transmitter or UART This UART is programmable for any rate from 110 to over 1 000 000 bits per second It can...

Страница 260: ...ight or nine this allows for 8 bit transmission with parity In either case the receive circuitry expects to see one start bit eight or nine data bits and at least one stop bit Receive mode is set by b...

Страница 261: ...T BUFFER EMPTY Not a mirror interrupt occurs when the buffer becomes empty When bit 14 is a 1 the data in the output data register SERDAT has been transferred to the serial output shift register so SE...

Страница 262: ...ite the data into this register the system will begin the transmission at the baud rate you selected At the start of the operation this data is transferred from SERDAT into an internal serial shift re...

Страница 263: ...ster stops shifting and signals shift register empty TSRE when there is a 1 bit present in the bit shifted out position and the rest of the contents of the shift register are 0s When new nonzero conte...

Страница 264: ...p the 16 combinations to 16 arbitrary colors Note that the sync signals from the Amiga are unbuffered For use with any device that presents a heavy load on the sync outputs external buffers will be re...

Страница 265: ...256 Interface Hardware...

Страница 266: ...APPENDIX A REGISTER SUMMARY ALPHABETICAL ORDER This appendix contains the definitive summary in alphabetical order of the register set and the uses of the individual bits Appendix A 257...

Страница 267: ...ing a read only register will cause unexpected results All of the pointer type registers are organized as 32 bits on a long word boundary These registers may be written with one MOVE L instruction The...

Страница 268: ...2 Use audio channel 1 to modulate period of channel 2 04 USE0P1 Use audio channel 0 to modulate period of channel 1 03 USE3VN Use audio channel 3 to modulate nothing 02 USE2V3 Use audio channel 2 to m...

Страница 269: ...ans that the smallest number that should be placed in this register is 124 decimal This corresponds to a maximum sample frequency of 28 86 kHz AUDxVOL 0A8 W P Audio channel x volume This register cont...

Страница 270: ...X 10 USEB X 09 USEC X 08 USED X 07 LF7 X 06 LF6 X 05 LF5 X 04 LF4 EFE 03 LF3 IFE 02 LF2 FCI 01 LF1 DESC 00 LF0 LINE 0 ASH 3 0 Shift value of A source BSH 3 0 Shift value of B source USEA Mode control...

Страница 271: ...single bit true 8000 most bits LINE DRAW will pass the C field unchanged LINE DRAW not A and C hut one bit will LINE DRAW invert the C field and combine it LINE DRAW with texture A and B and not C LIN...

Страница 272: ...5 h4 h3 h2 h1 h0 w5 w4 w3 w2 w1 w0 h height vertical lines 10 bits 1024 lines max w width horizontal pixels 6 bits 64 words 1024 pixels max LINE DRAW BLTSIZE controls the line length and starts LINE D...

Страница 273: ...low 15 bits This pair of registers contains the 18 bit address of blitter source x A B C or destination x D DMA data This pointer must be preloaded with the starting address of the data to be processe...

Страница 274: ...1P1 00 X PF1H0 PF1lP0 HIRES High resolution 640 mode BPU Bit plane use code 000 110 NONE through 6 inclusive HOMOD Hold and modify mode DBLPF Double playfield PF1 odd PF2 even bit planes COLOR Composi...

Страница 275: ...state if included It also controls the individual inclusion of odd numbered sprites in the collision detection by logically OR ing them with their corresponding even numbered sprite BIT FUNCTION DESC...

Страница 276: ...to sprite 2 or 3 01 Playfield 1 to sprite 0 or 1 00 Playfield 1 to playfield 2 COLORxx 180 W D Color Table xx There are 32 of these registers xx 00 31 and they are sometimes collectively called the co...

Страница 277: ...is is a dummy address that is generated by the Copper whenever it is loading instructions into its own instruction register This actually occurs every Copper cycle except for the second IR2 cycle of t...

Страница 278: ...omparison bit VE Enable comparison mask bit HE Enable comparison mask bit NOTE BFD Blitter finished disable When this bit is true the Blitter Finished flag will have no effect on the Copper When this...

Страница 279: ...me It is important that one of the jump registers be initialized and its jump strobe address hit after power up but before Copper DMA is initialized This insures a determined startup address and state...

Страница 280: ...TRT left edge of display data fetch PURPOSE H8 H7 H6 H5 H4 Extra wide max 0 0 1 0 1 Wide 0 0 1 1 0 Normal 0 0 1 1 1 Narrow 0 1 0 0 0 DDFSTOP right edge of display data fetch PURPOSE H8 H7 H6 H5 H4 Nar...

Страница 281: ...e all DMA below 08 BPLEN Bit plane DMA enable 07 COPEN Copper DMA enable 06 BLTEN Blitter DMA enable 05 SPREN Sprite DMA enable 04 DSKEN Disk DMA enable 03 AUD3EN Audio channel 3 DMA enable 02 AUD2EN...

Страница 282: ...SKLEN 024 W P Disk length This register contains the length number of words of disk DMA data It also contains two control bits a DMA enable bit and a DMA direction read write bit BIT FUNCTION DESRIPTI...

Страница 283: ...ck finished 07 AUD0 4 Audio channel 0 block finished 06 BLIT 3 Blitter finished 05 VERTB 3 Start of vertical blank 04 COPER 3 Copper 03 PORTS 2 I O ports and timers 02 SOFT 1 Reserved for software ini...

Страница 284: ...d multiplexed into the DENISE chip during the clock times shown in the Table This Table is for reference only and should not be needed by the programmer Note that the joystick functions are all active...

Страница 285: ...NECTORS PAULA Loc Dir Sym Pin Pin Pin Name RIGHT Y RY 9 36 POT1Y RIGHT X RX 5 35 POT1X LEFT Y LY 9 33 POT0Y LEFT X LX 5 32 POT0X POTGO 034 W P Pot port data write and start POTGOR 016 R P Pot port dat...

Страница 286: ...ffer This address reads data from a receive data buffer Data in this buffer is loaded from a receiving shift register whenever it is full Several interrupt request bits are also read at this address a...

Страница 287: ...e Low bit SH0 is in SPRxCTL register below SPRxCTL register writing this address disables sprite horizontal comparator circuit BIT SYM FUNCTION 15 08 EV7 EV0 End stop vertical value low 8 bits 07 ATT...

Страница 288: ...cond refresh time slot of every other line to identify lines with long counts 228 There are four refresh time slots and any not used for strobes will leave a null FF address on the destination address...

Страница 289: ...280 Appendix A...

Страница 290: ...APPENDIX B REGISTER SUMMARY ADDRESS ORDER This appendix contains information about the register set in address order Appendix B 281...

Страница 291: ...nation address bus S Strobe write address with no register bits Writing the register causes the effect PTL PTH Chip memory pointer that addresses DMA data Must be reloaded by a processor before use ve...

Страница 292: ...SERPER 032 W P Serial port period and control POTGO 034 W P Pot port data write and start JOYTEST 036 W D Write to all 4 joystick mouse counters at once STREQU 038 S D Strobe for horiz sync with VB a...

Страница 293: ...clear or set bits ADKCON 09E W P Audio disk UART control AUD0LCH 0AO W A Audio channel 0 location high 3 bits AUD0LCL 0A2 W A Audio channel 0 location low 15 bits AUD0LEN 0A4 W P Audio channel 0 lengt...

Страница 294: ...bits BPL6PTL 0F6 W A Bit plane 6 pointer low 15 bits 0F8 0FA 0FC 0FE BPLCON0 100 W A D Bit plane control register misc control bits BPLCON1 102 W D Bit plane control reg scroll value PF1 PF2 BPLCON2...

Страница 295: ...ge data register B SPR1POS 148 W A D Sprite 1 vert horiz start position data SPR1CTL 14A W A D Sprite 1 vert stop position and control data SPR1DATA 14C W D Sprite 1 image data register A SPR1DATB 14E...

Страница 296: ...Table 06 COLOR07 18E W D Color Table 07 COLOR08 190 W D Color Table 08 COLOR09 192 W D Color Table 09 COLOR10 194 W D Color Table 10 COLORll 196 W D Color Table 11 COLOR12 198 W D Color Table 12 COLOR...

Страница 297: ...288 Appendix B...

Страница 298: ...APPENDIX C CUSTOM CHIP PIN ALLOCATION LIST NOTE Means an active low signal Appendix C 289...

Страница 299: ...posite sync O 40 HSY Horizontal sync I O 41 VSS Ground I 42 48 D15 D9 Data bus lines 15 to 9 I O DENISE PIN ASSIGNMENT PIN DESIGNATION FUNCTION DEFINITION 01 07 D6 D0 Data bus lines 6 to 0 I O 08 M1H...

Страница 300: ...vel 3 I 18 INT6 Interrupt level 6 I 19 26 RGA8 RGA1 Register address bus 8 1 I 27 VCC 5 Volt I 28 CCK Color clock I 29 CCKQ Color clock delay I 30 AUDB Right audio O 31 AUDA Left audio O 32 POT0X Pot...

Страница 301: ...r clock I 35 XCLR Alternate master clock I 36 XCLKEN Master clock enable I 37 CDAC Inverted shifted 7MHZ clk O 38 7MHZ 28MHZ clk divided by four O 39 CCRQ Color clock delay O 40 CCR Color clock O 41 T...

Страница 302: ...APPENDIX D SYSTEM MEMORY MAP Appendix D 293...

Страница 303: ...GE NOTES 000000 03FFFF 256K Bytes of chip RAM 040000 07FFFF 256K bytes of chip RAM option card 080000 0FFFFF 512K Extended chip RAM to 1 MB 100000 1FFFFF Reserved Do not use 200000 9FFFFF Primary 8 MB...

Страница 304: ...de timing or loading information The second part briefly describes the functions of those pins whose purpose may not be evident The third part contains a list of the connections for certain internal c...

Страница 305: ...ccess in order to assure compatibility of their software with the system PART 1 OUTSIDE WORLD CONNECTORS This is a list of the connections to the outside world on the Amiga RS232 and MIDI Port A500 CB...

Страница 306: ...lup AUTODXT 15 GND NC ERROR 16 GND RESET INIT 17 GND GND SLCT IN 18 22 GND GND GND 23 5 GND GND 24 NC GND GND 25 Reset GND GND KEYBOARD RJ11 A1000 A2000 1 5 Volts KCLK 2 CLOCK KDAT 3 DATA NC 4 GND GND...

Страница 307: ...00 with A2000 differences noted 1 RDY 13 SIDEB 2 DKRD 14 WPRO 3 GND 15 TK0 4 GND 16 DKWEB 5 GND 17 DKWDB 6 GND 18 STEPB 7 GND 19 DIRB 8 MTRXD 20 SEL3B A2000 not used 1 9 SEL2B A2000 SEL3B 1 21 SEL1B A...

Страница 308: ...8 D8 J D9 9 gnd K gnd 10 D7 L D6 11 5 M 5 12 D4 N D5 13 gnd P gnd 14 D3 R D2 15 5 S 5 16 D0 T D1 17 gnd U gnd 18 DRA4 V DRA3 19 DRA5 W DRA2 20 DRA6 X DRA1 21 DRA7 Y DRA0 22 gnd Z gnd 23 RAS AA RRW 24...

Страница 309: ...Clock 16 x x x x C1 Clock 17 x x x x OVR 18 x x x x RDY 19 x x x x INT2 20 x PALOPE x x No Connect x BOSS 21 x x x x A5 22 x x x x INT6 23 x x x x A6 24 x x x x A4 25 x x x x ground 26 x x x x A3 27 x...

Страница 310: ...x x x x DTACK 67 x x x x D13 68 x x x x R W 69 x x x x D12 70 x x x x LDS 71 x x x x D11 72 x x x x UDS 73 x x x x Ground 74 x x x x AS 75 x x x x D0 76 x x x x D10 77 x x x x D1 78 x x x x D9 79 x x...

Страница 311: ...e See timing diagrams in the following section D0 I O Dl I O D2 I O D3 I O D0 D7 comprise an eight bit bidirectional bus D4 I O for communication with parallel devices D5 I O nominally a printer D6 I...

Страница 312: ...wledge delay TS nsp x upc Acknowledge width nsp not specified upc under program control PARALLEL CONNECTOR INTERFACE TIMING INPUT CYCLE PA 7 0 _____ ____________________________________________ ____ P...

Страница 313: ...to frame ground CD I y Carrier detect 5V n 50 ma maximum WARNING 5V AUDO O n Audio output from left channels 0 3 port intended to send audio to the modem AUDI I n Audio input to right channels 1 2 por...

Страница 314: ...nterface to four types of devices 1 Mouse or trackball 3 buttons max 2 Digital joystick 2 button max 3 Proportional pot or proportional joystick 2 buttons max 4 Light pen including pen pressed to scre...

Страница 315: ...can be resolved as follows Velocity Distance max SampleTime Velocity SQRT DeltaX 2 DeltaY 2 SampleTime For an Amiga with a 200 count per inch mouse sampling during each vertical blanking interval the...

Страница 316: ...JOYSTICK INPUTS PIN MNEMONIC DESCRIPTION HARDWARE REGISTER NOTES 1 FORWARD Forward joystick switch JOY 0 1 DAT 9 xor 8 2 BACK Back joystick switch JOY 0 1 DAT 1 xor 0 3 LEFT Left joystick switch JOY 0...

Страница 317: ...ence level while counter keeps track of the number of lines since the end of the reset interval 3 When the input voltage finally exceeds the internal threshold for a given input channel the current co...

Страница 318: ...sweeps past the light pen a trigger pulse is generated which can be enabled to latch the horizontal and vertical beam positions There is no hardware bit to indicate this trigger but this can be deter...

Страница 319: ...5V 270 ma maximum 410 ma surge When below 3 75V drives are required to reset their motor on flopa and set their write protect flops 13 SIDEB O Side 1 if active side 0 if inactive 14 WPRO I O Asserted...

Страница 320: ...t is received first EXTERNAL DISK CONNECTOR DEFINED IDENTIFICATIONS 0000 0000 no drive present FFFF FFFF Amiga standard 3 25 diskette 5555 5555 48 TPI double density double sided As with other periphe...

Страница 321: ...MTROD led 21 GND 5 GND 22 DKWDB 6 N C 23 GND 7 GND 24 DKWEB 8 IND B 25 GND 9 GND 26 TK0 10 SELOB 27 GND 11 GND 28 WPRO 12 N C 29 GND 13 GND 30 DKRD 14 N C 31 GND 15 GND 32 SIDEB 16 MTROD 33 GND 17 GN...

Страница 322: ...P4 data 4 data PB3 P3 data 3 PB2 P2 data 2 PBl P1 data 1 PB0 P0 data 0 PC drdy Centronics control F ack Address BFDRFE data bits 15 8 A13 int6 PA7 com line DTR driven output PA6 com line RTS driven o...

Страница 323: ...____________ PORT 1 __________________ POTOX o_ ________________________ o__ ___________ ____________ POTOY ______V_____________V______ POT1Y POT1X COUNTER COUNTER POT1DAT LATCH LATCH DFF014 _________...

Страница 324: ...___ ___________________________________________________ FIRE FIRE PRA 1 0 BFE001 ______ ______ ______ ______ ______ ______ ______ ______ 7 0 ______________ ____________________________________________...

Страница 325: ...________________________________ BPLCON0 write only DFF104 __ __ __ __ __ __ __ __ __ __ __ _ __ __ __ 15 3 0 ________Light Pen Enable ____________________________________________ POT1NP read only DFF...

Страница 326: ...INTERFACE ADAPTOR CIA CHIPS Each Amiga system contains two 8520 Complex Interface Adaptor CIA chips Each chip has 16 general purpose input output pins plus a serial shift register three timers an out...

Страница 327: ...AA control register A BFEF01 crb CIAA control register B Note CIAA can generate interrupt INT2 CIAB Address Map Byte Register Data bits Address Name 7 6 5 4 3 2 1 0 BFD000 pra DTR RTS CD CTS DSR SEL P...

Страница 328: ...ial data register 1 1 0 1 D icr Interrupt control register 1 1 1 0 E cra Control register A I 1 1 1 F crb Control register B SOFTWARE NOTE The operating system kernel has already allocated the use of...

Страница 329: ...using the PC output pin and the FLAG input pin PC will go low on the third cycle after a port B access This signal can be used to indicate data ready at port B or data accepted from port B Handshaking...

Страница 330: ...he timer output to appear on a port B output line PB6 for timer A and PB7 for timer B This function overrides the DDRB control bit and forces the appropriate PB line to become an output TOGGLE PULSE A...

Страница 331: ...load or following a write to the high byte of the pre scalar while the timer is stopped If the timer is running a write to the high byte will load the timer latch but not the counter BIT NAMES on READ...

Страница 332: ...tart again until after a write to the LSB event register This assures that TOD will always start at the desired time Since a carry from one stage to the next can occur at any time with respect to a re...

Страница 333: ...he speed at which the receiver responds to input data To begin transmission you must first set up Timer A in continuous mode and start the timer Transmission will start following a write to the serial...

Страница 334: ...gister Any interrupt that is enabled by a 1 bit in that position in the MASK will set the IR bit MSB of the DATA register and bring the IRQ pin low In a multichip system the IR bit can be polled to de...

Страница 335: ...ant to set the Timer A interrupt bit enable the Timer A interrupt but want to be sure that all other interrupts are cleared Here is the sequence you can use INCLUDE hardware cia i XREF ciaa From amiga...

Страница 336: ...ccurs during one shot mode 1 PBON 1 Timer A output on PB6 0 PB6 is normal operation 2 OUTMODE 1 toggle 0 pulse 3 RUNMODE 1 one shot mode 0 continuous mode 4 LOAD 1 force load this is a strobe input th...

Страница 337: ...rmal operation 2 OUTMODE 1 toggle 0 pulse RUNMODE 1 one shot mode 0 continuous mode 4 LOAD 1 force load this is a strobe input there is no data storage bit 4 will always read back a zero and writing a...

Страница 338: ...programmer to relate the port addresses to the outside world items or internal control signals which are to be affected This part is primarily for the use of the systems programmer and should generall...

Страница 339: ...PBl P1 data 1 PBO P0 data 0 PC drdy centronics control F ack Address BFDrOO data bit 15 8 A13 INT6 PA7 com line DTR driven output PA6 com line RTS driven output PA5 com line carrier detect PA4 com li...

Страница 340: ...2148 INCLUDE hardware cia i INCLUDE hardware custom i XREF _ciaa XREF _ciab XREF _custom lea _custom a3 Base of custom chips lea _ciaa a4 Get base address if CIA A move w S7fff dmacon a3 Kill all chip...

Страница 341: ...no other INTERFACE SIGNALS CLOCK INPUT The 02 clock is a TTL compatible input used for internal device operation and as a timing reference for communicating with the system data bus On the Amiga this...

Страница 342: ...NTERRUPT REQUEST OUTPUT IRQ is an open drain output normally connected to the processor interrupt input An external pull up resistor holds the signal high allowing multiple IRQ outputs to be connected...

Страница 343: ...334 Appendix F...

Страница 344: ...ard its address space preferences type of board memory or other and a unique Hardware Manufacturer Number assigned by Commodore Amiga Technical Support West Chester Pennsylvania Each board contains co...

Страница 345: ...RAM boards without using the Amiga operating system Such applications should only configure expansion RAM boards boards which ask to be added to the free memory list and known dedicated boards designe...

Страница 346: ...the first 80 bytes of an AUTOCONFIG board at configuration time NOTES o Identification information is stored in the high nibbles of the even word addresses at the start of an AUTOCONFIG board For exam...

Страница 347: ...5 4 3 2 1 0___Board size 000 8meg 100512k Read __ __ 001 64k 101 1meg Not Inverted 010 128k 110 2meg 011 256k 111 4meg 1 Next card is also on this board 1 Optional ROM vector valid 1 Link into memory...

Страница 348: ...erial 1st byte msb 1C lE 7 6 5 4 3 2 1 0 Optional serial 2nd byte 20 22 7 6 5 4 3 2 1 0 Optional serial 3rd byte 24 26 7 6 5 4 3 2 1 0 Optional serial 4th byte lsb Read Inverted S28 2A 7 6 5 4 3 2 1 0...

Страница 349: ...re using the same interrupt line S44 46 7 6 5 4 3 2 1 0 Reserved read must be 00 R W Write undefined Inverted S48 4A 7 6 5 4 3 2 1 0 Base add register write only Write Only ___ ___ ___ ___ These bits...

Страница 350: ...he board printf er Manufacturer printf d myCD cd Rom er Manufacturer printf S x myCD cd Rom er Manufacturer printf 4x n myCD cd Rom er Manufacturer printf er Product printf d myCD cd Rom er Product pr...

Страница 351: ...342 Appendix G...

Страница 352: ...y connections The four wires provide 5 volt power ground and signals called KCLK keyboard clock and KDAT keyboard data KCLK is unidirectional and always driven by the keyboard KDAT is driven by both t...

Страница 353: ...compatibility with all keyboard models All codes transmitted to the computer are rotated one bit before transmission The transmitted order is therefore 6 5 4 3 2 1 0 7 The reason for this is to transm...

Страница 354: ..._________ KDAT __________ ____ ____ 0 1 1 0 1 0 1 0 In the next example the B key is released The keycode is still 35 except that bit 7 is set to indicate key up resulting in a code of B5 10110101 Aft...

Страница 355: ...to restore sync the garbage character thus transmitted will appear as a key release which is less dangerous than a key hit Whenever the keyboard detects that it has lost sync it will assume that the c...

Страница 356: ...re synchronizing due to a handshake time out Once the keyboard and computer are in sync the keyboard must inform the computer of the results of the self test If the self test failed for any reason a...

Страница 357: ...mal keystroke else the keyboard goes directly to Hard Reset On the second reset warning code the Amiga must drive KDAT low within 250 milliseconds else the keyboard goes directly to Hard Reset If the...

Страница 358: ...no up down flag associated with them However the transmission bit order is the same as previously described CODE NAME MEANING 78 Reset warning CTRL AMIGA AMIGA has been hit computer will be reset in 1...

Страница 359: ...Q PD 5 note 1 1 note 1 5E 31 20 10 01 5A 12 9 X S W f1 PD 4 note 3 2 3F 32 21 11 02 50 11 6 C D E f2 PD 3 note 3 3 2F 33 22 12 03 51 10 3 V F R f3 PD 2 note 3 4 1F 34 23 13 04 52 9 B G T f4 PD 1 note...

Страница 360: ...1 A500 and A2000 keyboards only numeric pad note 2 International keyboards only these keys are cutouts of the larger key on the US ASCII version The key that generates 30 is cut out of the left shift...

Страница 361: ...352 Appendix H...

Страница 362: ...connector at the rear of the main computer unit is used to interface to and control devices that generate and receive MFM data This interface can be reached either as a resource or under the control...

Страница 363: ...I O Track 0 16 DKWEB O Write gate 17 DKWDB O Write data 18 STEPB O Step 19 DIRB O Direction high is out 20 SEL3B O Select drive 3 21 SELlB O Select drive 1 22 INDEX I OO Index 23 12v PWR 120 mA averag...

Страница 364: ...it has a write protected diskette installed INDEX Pin 22 A selected drive pulses this signal low once for each revolution of its motor SIDEB Pin 13 The system drives this signal to all disk drives low...

Страница 365: ...oseconds after selecting the drive An external drives must have logic equivalent to a D flip flop whose D input is the MTRXD signal and whose clock input is activated by the off to on high to low tran...

Страница 366: ...o a 16 bit word The most significant bit is the first value and so on This 16 bit quantity is the device I D The following I D s are defined 0000 0000 0000 0000 Reserved 1111 1111 1111 1111 Amiga stan...

Страница 367: ...358 Appendix I...

Страница 368: ...n Appendix A and Appendix B to names that can be resolved by the standard include files Use of these names in code sections of this manual places the emphasis on what the code is doing rather than get...

Страница 369: ...o wait forever since the wait command described in it will never happen COPPER_HALT equ FFFFFFFE This is the offset in the 680x0 address space to the custom chip registers It is the same as custom whe...

Страница 370: ...u bltcpt BLTCPTH equ bltcpt BLTCPTL equ bltcpt 02 BLTBPT equ bltbpt BLTBPTH equ bltbpt BLTBPTL equ bltbpt 02 BLTAPT equ bltapt BLTAPTH equ bltapt BLTAPTL equ bltapt 02 BLTDPT equ bltdpt BLTDPTH equ bl...

Страница 371: ...C equ aud3 AUD3LCH equ aud3 AUD3LCL equ aud3 02 AUD3LEN equ aud3 04 AUD3PER equ aud3 06 AUD3VOL equ aud3 08 AUD3DAT equ aud3 0A The bitplane registers BPLlPT equ bplpt 00 BPLlPTH equ bplpt 00 BPLlPTL...

Страница 372: ...rpt 1C SPR7PTH equ SPR7PT 00 SPR7PTL equ SPR7PT 02 Note SPRxDATB is defined as being 06 from SPRxPOS sd_datab should be defined as 06 however in the 1 3 assembler include file hardware custom i it is...

Страница 373: ...COLOR03 equ color 06 COLOR04 equ color 08 COLOR05 equ color 0A COLOR06 equ color 0C COLOR07 equ color 0E COLOR08 equ color 10 COLOR09 equ color 12 COLOR10 equ color 14 COLOR11 equ color 16 COLOR12 eq...

Страница 374: ...In sprites a mode in which a sprite uses two DMA channels for additional colors In sound production combining two audio channels for frequency amplitude modulation or for stereo sound AUTOMATIC MODE...

Страница 375: ...g when sprites playfields or playfield objects attempt to overlap in the same pixel position or attempt to cross some pre defined boundary COLOR DESCRIPTOR WORDS Pairs of words that define each line o...

Страница 376: ...es and video output DEPTH Number of bit planes in a display DIGITAL TO ANALOG CONVERTER A device that converts a binary quantity to an analog level DIRECT MEMORY ACCESS An arrangement whereby intellig...

Страница 377: ...UTION A horizontal display mode in which 640 pixels are displayed across a horizontal line in a normal sized display HOLD AND MODIFY A display mode that gives you extended color selection up to 4 096...

Страница 378: ...be aware of any other task NANOSECOND NS One billionth of a second 1 1 000 000 000 NON INTERLACED MODE A display mode in which 200 lines are displayed from top to bottom of the video display in a nor...

Страница 379: ...al analog device used to adjust some variable value PRIMITIVES Amiga graphics text and animation library functions QUANTIZATION NOISE Audio noise introduced by round off errors when you are trying to...

Страница 380: ...s to have full control over its own virtual 68000 machine TIMBRE Tone quality of a sound TRACKBALL A controller device that you spin with your hand to move something on the screen may have buttons for...

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