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Detail 1-7B

Refer to Detail 1-7B and cut off the indicated 
lugs at one end of the remaining 20-pin socket.

Push the prepared 20-pin socket onto the edge 

of the circuit board next to the 6-pin sockets. 

Make sure the circuit board is between the two 
lugs at each socket connector. Also make sure 
each lug lines up with a foil on the circuit board. 
NOTE: The socket hole where you cut off the 
lugs must be between foil contact 49 and the 
nearby corner of the circuit board. Solder only 
lugs 31 and 49 to the foil on the component side 
of the circuit board.

( ) Locate the 25-pin plug. Thenreferto Detail 1-7C 

and push the longer pins of the plug into the 
four sockets as shown.

( ) Check the four sockets to make sure the edges of 

each socket are parallel to the surfaces of the 
circuit board.

(  ) Adjust the sockets as necessary so they are

parallel to the circuit board. Then solder all the 
socket lugs to the circuit board (both sides).

(  ) Remove and discard the 25-pin plug.

Detail 1-7C

Summary of Contents for HEATHKIT HA8-8

Page 1: ...HEATHKIT MANUAL HEATH COMPANY BENTON HARBOR MICHIGAN...

Page 2: ...expense to the Heath factory any Heathkit Electronic Center or any of our authorized overseas distributors You will receive free consultation on any problem you might encounter in the assembly or use...

Page 3: ...hkit Manual for the EXTENDED CONFIGURATION BOARD Model HA8 8 595 2509 01 HEATH COMPANY BENTON HARBOR MICHIGAN 49022 Copyright 1980 Heath Company All Rights Reserved Printed in the United States of Ame...

Page 4: ...ORG 0 24 Side Select 28 Modification Tests 30 Circuit Description 31 Circuit Board X Ray View 32 Integrated Circuit Identification 33 Schematic Fold in Warranty Inside front cover Customer Service Ins...

Page 5: ...illustrate a single step When you are directed to refer to a certain Pictorial for the following steps continue using that Pictorial until you are referred to another Pictorial for another group of s...

Page 6: ...form an electrical connection be tween two parts such as a component lead and a circuit board foil A bad solder connection could pre vent an otherwise well assembled kit from operating properly It is...

Page 7: ...w 4 Green 5 Blue 6 Violet 7 Gray 8 White 9 Multiplier Color Multiplier Black 1 Brown 10 Red 100 Orange 1 000 Yellow 10 000 Green 100 000 Blue 1 000 000 Silver 0 01 Gold 0 1 Resistance Tolerance Color...

Page 8: ...r C1 C2 C5 B2 25 221 2 2 2 j F tantalum capacitor C3 C4 INTEGRATED CIRCUITS NOTE Integrated circuits are marked for identification in one of the following four ways 1 Part number 2 Type number This re...

Page 9: ...Heathkit PARTS PICTORIAL ALWAYS IDENTIFY AN I C BY THE PART NUMBER OR TYPE NUMBER NOTE THE STYLE MAY BE SLIGHTLY DIFFERENT THAN SHOWN a a s...

Page 10: ...on the circuit board Push the leads through the holes at the indicated location on the circuit board The end with color bands may be positioned either way Press the resistor against the cir cuit board...

Page 11: ...nec tion SOLDER BRIDGES A solder bridge between two adjacent foils is shown in photograph A Photograph B shows how the con nection should appear A solder bridge may occur if you accidentally touch an...

Page 12: ...brn blk red resis tors at the following locations R3 RB R4 C5 01 p F 103 ceramic capacitor Solder the leads to the foil and cut off the excess lead lengths CONTINUED Cl 01 p F 103 ceramic capacitor R2...

Page 13: ...rcuit board foil side down as shown and hold the soldering iron tip between the two points that are bridged The solder will flow down the soldering iron tip CIRCUIT BOARD IC SOCKET 7ZZZ FOIL SOLDERING...

Page 14: ...es at the eight locations indicated SW1 8 section slide switch Mount the switch so the numbers 0 through 7 are away from integ rated circuit U1 as shown Then solder the lugs to the foil and cut off an...

Page 15: ...ou apply downward pressure to the IC make sure each pin is cen tered in its proper socket hole Handle IC s with care as their pins are very easily bent Should it ever become necessary to remove an IC...

Page 16: ...ontacts 24 and 25 as shown Detail 1 6A NOTE Perform the following carefully The sockets are very difficult to remove once they are installed wrong Use the following procedure to install one ofthe 26 p...

Page 17: ...o that about half of the plug pins are in each socket Adjust the sockets as necessary so they are parallel to the circuit board Then solder all the socket lugs to the circuit board both sides Remove a...

Page 18: ...on the component side of the circuit board The other pins will be soldered later Locate a 6 pin socket Then refer to Detail 1 7A and cut off the indicated lugs at one end of the socket Push the prepar...

Page 19: ...f the lugs must be between foil contact 49 and the nearby corner of the circuit board Solder only lugs 31 and 49 to the foil on the component side of the circuit board Locate the 25 pin plug Thenrefer...

Page 20: ...to the component side of the circuit board in the location shown Position the circuit board as shown in Pictorial 1 9 with the component side away from you Carefully peel the backing paper from the re...

Page 21: ...d 1 8 of insulation from the other end of a 12 red wire Twist the strands at each end of the wire tightly together Then melt a very small amount of solder on these ends to hold the fine strands togeth...

Page 22: ...follows Position the Extended Configuration Board in side the chassis as shown NOTE You must install this circuit board with the components toward the rear panel Then carefully push the connectors on...

Page 23: ...r solder bridges or other construction errors TEST 2 Check the upper right corner of your CPU cir cuit board for the presence of a jumper wire between holes Xl and X2 If there is a jumper wire at this...

Page 24: ...obtained the proper results proceed to Status Port NOTE The following sections describe the three functions available with the Extended Configuration Board and some modifications that you must make to...

Page 25: ...Port 170 78H l73Q 7BH is not in use normal without H47 01 Port 170 173Q has an H47 normal with H47 10 Undefined 11 Undefined 0 Boots from device at port 174 177Q H17 normal I 1 Boots from device at p...

Page 26: ...the bus pin 46 low when a write is performed at I O address 362Q 0F2H and it sets data bit D5 to a logic 1 This in turn disables the ROM on the CPU circuit board and allows you to address the RAM betw...

Page 27: ...This capacitor will no longer be used Refer again to the inset drawing and carefully unsolder or cut the leads of resistor R6 68 ft blu gry blk This resistor will no longer be used Cut a 3 4 length o...

Page 28: ...he following lengths of green wire Then remove 1 4 of insulation from the ends of each wire 1 1 2 2 3 4 Connect and solder one end of the 1 1 2 green wire to hole T2 Connect and solder the other end o...

Page 29: ...rcuit Read the entire instruction first Then carefully do each step without interruption IC204 Install a ROM IC 444 70 at IC204 in your CPU circuit board as follows 1 Remove the IC from the conductive...

Page 30: ...perform a side select You can configure your Computer to use the side select function in two ways Method 1 preferred allows you to use an unused bus line while Method 2 requires a connection to the H...

Page 31: ...nsulation from each end Position the controller circuit board as shown in Pictorial 2 8 Then solder one end of the 3 1 2 green wire to the foil at pin 32 of socket S103 on your controller circuit boar...

Page 32: ...ly the center pin is used Reinstall the tie bracket and top cover on your Computer MODIFICATION TESTS The following test will check the modifications that you made on your CPU circuit board To make th...

Page 33: ...buffer via pins 1 and 19 ROM DISABLE Latch U3A and buffer U6D generate the ROM DIS ABLE signal If data bit D5 is low and a write is performed at I O address 362Q the write signal 362IOW from U6B clock...

Page 34: ...umber R5 C3 etc on the X Ray View B Locate this same number in the Circuit Com ponent Number column of the Parts List C Adjacent to the circuit component number you will find the PART NUMBER and DESCR...

Page 35: ...LACED TOP VIEW DESCRIPTION LEAD CONFIGURATION U1 442 54 7805 5 volt regulator OUT OUT U2 443 754 74LS240 Tri state inverting buffer 2G 1V1 2A4 1V2 2A3 1Y3 2A2 1Y4 2A1 1G 1A1 2A4 1A2 2Y3 1A3 2Y2 1A4 2Y...

Page 36: ...Integrated Circuits cont d...

Page 37: ...voltage readings and any other infor mation you think might be helpful Please do not send parts for testing unless this is specifi cally requested by our Consultants Hints Telephone traffic is lighte...

Page 38: ...HEATH HEATH COMPANY BENTON HARBOR MICHIGAN THE WORLD S FINEST ELECTRONIC EQUIPMENT IN KIT FORM...

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