H8-8080A 28C256 EEROM adapter!

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norberto.collado koyado.com

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Jul 29, 2022, 7:35:05 PM (10 days ago) Jul 29
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Joseph Travis came with the idea of expanding the ROM space on the 8080A CPU board. This will allow to add extra features while keeping the original XCON-8 FW. 

Based on feedback from Joe, I put together the following board to achieve this. 

The original 8080A ROM socket (IC 204) will pick up addresses from A0 to A12. Then A13 and A14 can be soldered to the 8080A board to expand such address range. Also, you can manually control A13/A14 thru the jumper by selecting GND or VCC to either pin.

I need help in finding the pins to insert into the IC 204 socket as the round pins will damage IC 204 socket. I do not want to replace IC 204 socket with a machine tooled low profile IC socket as the board could be damaged in the process.

Attached is the diagram and board layout. I will post to the website tonight.

Thanks,
Norberto


8080A_2732_EEPROM.pdf

norberto.collado koyado.com

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Jul 29, 2022, 8:08:53 PM (10 days ago) Jul 29
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Looking for this type of IC socket but with the IC flat fins on one side (not round pins) pins for a 24 pin ROM socket.



From: se...@googlegroups.com <se...@googlegroups.com> on behalf of norberto.collado koyado.com <norberto...@koyado.com>
Sent: Friday, July 29, 2022 4:34 PM
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Subject: [sebhc] H8-8080A 28C256 EEROM adapter!
 
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