Basic eprom for nms8220

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Van sdsnatcher73

Prophet (2223)

afbeelding van sdsnatcher73

03-01-2021, 06:27

sdsnatcher73 wrote:

@Roadfighter: I sent the file to your e-mail (may end up in a spam folder so please check)

Now sent to @makinajava who actually needs it Wink

Van makinavaja

Master (219)

afbeelding van makinavaja

03-01-2021, 13:24

Manuel wrote:

Perhaps you missed my post in which I explained how the ROMs are organized inside the 128kB EPROM? Also, you seem to have missed the subROM?

Yes, I did, didn't read it correctly, undertood something else oO oO
Anyway, thanks for your answer, and thanks to everybody for their help (specially you @sdsnatcher73 for the rom Wink )

I will keep you updated about this computer

Van sdsnatcher73

Prophet (2223)

afbeelding van sdsnatcher73

03-01-2021, 14:21

Looking at the 128kB dump and the pinouts of the original Mask ROM and a 27512 chip you are probably better of programming the first 64kB of the ROM dump (which contains all that is needed on the NMS8220). Only thing I don't know is what you should do with pin 22. It is A16 on the mask ROM (which is most likely always low in the NMS8220) but It is /OE on the 27512. My guess is that it should also be low to enable output so most likely placing the programmed 27512 in the board will be enough.

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