Page 2.88
CIRCUIT DESCRIPTION
To see when the BUSY line goes to the inactive state, it moni-
tors the logic level of PAO. This simplifies programming since,
otherwise, CB2 must be programmed to respond to the oppo-
site-polarity signal transition.
The CPU uses the INIT line to initialize some printers. It does
this by sending a short pulse (typically 50 ns) to the printer.
The ERROR line asserts if a printer failure occurs, such as
when the ribbon needs changing, or when the printer runs
out of paper. The CPU stops sending characters until the error
is fixed.
Light Pen Port
The light pen circuits consist of U134D, U134B, U134C,
U116E, U131, and part of the PIA at U114.
The CPU cannot respond to a signal from the light pen circuits
without a user-supplied program to set up interrupts, handle
timing, and take care of bit locations detected by the light
pen. As a result, this discussion can only be general.
When the CPU lights a dot on the CRT within the range of
the light pen, the light pen sends a pulse to U134 pin 5.
Jumper J103 allows triggering from either the leading or trail-
ing edge of this pulse. The jumper should be set so that the
leading edge always triggers flip-flop U131.
This pulse latches a logic 1 into U131 pin 5, which couples
through U116E to the light pen strobe input in the CRT Con-
troller, or CRTC (U330), on the video board. The CRTC saves
the address of the byte being accessed. (See the "Theory
of Operation" on Page 4.64 in the "Video Board" part of this
Manual for more details.)
The output of U131 also couples to pin 40 of U114, a 68A21
peripheral interface adapter. The rising edge of the signal at
Содержание Z-100 Series
Страница 2: ...This Document was scanned and contributed by...
Страница 7: ......
Страница 37: ......
Страница 163: ...page 2 125 SEMICONDUCTOR IDENTIFICATION IODEC E 0 decoder for the Z 100 Macros Symbols No Fatal er r or s...
Страница 171: ...page 2 133 SEMICONDUCTOR IDENTIFICATION...
Страница 322: ......
Страница 354: ...Dp p 50 100 0 0 0 4 e C3 4 4 0 Ph Ir COMPONENT BOTTOM S IDE SIDE 0 cs 0 lJ JJ JJ 0 OX g gi l 4 S100 BUS CONNECTION...
Страница 355: ...I N STATUS PORT T E R F A C E CONTROL LATCH 5 25 1797 DATA AND WR ITE PRECOMPEN SATION SEPARATION BLOCK DIAGRAM...
Страница 374: ...G ND CP2 CP3 R 3 R 4 o Ij QQQQQQQQQ Q Q Q Q Q Q Q Q Q XXQXXQQXQ Q Q amzm PICTORIAL 6 5 Caiibration Locations...
Страница 390: ...R9 1 R4 Ri R1 TG43 PS U1 R 19 U18 U21 I Z 14 UaS U32 CIRCUIT I Shown from the c component...
Страница 397: ...Page 7 1 5 1 4 Floppy Drives 7 2 Description Programming Cable Connections Operation 7 5 7 6...
Страница 404: ......
Страница 405: ...Page 8 1 Power Supply Power Line Considerations Specifications 8 2 8 3...
Страница 411: ...page 9 3 REPLACEMENT PARTS LIST V s 1 s I t V p 10 ALL IN ONE...
Страница 415: ...Page 9 7 ACE5fENT p4RTS L 45 44 43 46 61 42 60 40 50 52 I...
Страница 417: ...page 9 9 REPLACEMENT PARTS LIST 1 4 9 io 20 1II l I i jj e e 1 I 17...
Страница 419: ...Page 9 f E LACEMENT pRTS LIST 23 24 h 2S 26 28 29 L 41 40 C 3 0 I t tj t 3 4 Q t...
Страница 426: ......