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D8085AC and D27128D extracting program from EPROM
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Dom87:
Hi folks.

I have an old piece of test equipment that uses an old school D8085AC processor and what appears to be a NEC D27128D as its EPROM.
I was wondering how difficult it would be to extract the instructions from the D27128D and turn it into something meaningful, like assembly, that I could use to start figuring out the functionality.

Thanks
Deni:
Reading out EPROM is easy - there are many device programmers on the market, you can even build your own one usind Arduino, for example.
The next step, disassembly, shoudl be simple too - there are many disassemblers for 8080/85. Analyzing disassembled code - well, that's up to your skills and persistence...
Dom87:
Thanks Deni.

I found this article here from a blog called Dances with Ferrets...  ;D https://danceswithferrets.org/geekblog/?p=315 and I now created an extract.
Is there any particular disassembler you would recommend?
eblc1388:
Hi Dom87,

The author's Eprom reader in your above link generate a hex dump with ASCII, which is then send to your serial port on the PC. Therefore, each 8-bit Eprom data is sent as two ascii bytes, and the text file you can then capture in the terminal.

However, most disassembler would only accept a true binary file image for disassembling. You will then need to do a lot of editing before the disassembler will accept it. You can modify the Arduino sketch to transfer the HEX data continuously without extra data like ascii representation, linefeed or carriage return, but then you still need to process the captured file into a true binary file.

I don't know if one can send a binary values of 0x00~0xFF directly via the serial port.

Regarding the disassembler, I would recommend the DASMx Version 1.40. Just search for "DASMx Version 1.40" in Google.

edit: added disassembler info
amyk:

--- Quote from: eblc1388 on May 09, 2020, 02:20:54 am ---I don't know if one can send a binary value of 0x00~0xFF directly via the serial port.
--- End quote ---
Yes you can, but you'd need some sort of framing protocol like PPP, HDLC, or SLIP. Otherwise it's just a stream of bytes.
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