Which chip for internal rom replacement

[orzel]

Hello,

Say i want to change the ROM chips in a amstrad cpc6128. Either the main 32k one, or the smallest (16k?) used by AMSDOS. I don't mean ROM expansions here.

Is there any modern, compatible chip i could use like a eeprom ? Or can't I avoid using a one-time-only PROM or (even worse) a windowed EPROM ?

[Rabs]

Hello,

Say i want to change the ROM chips in a amstrad cpc6128. Either the main 32k one, or the smallest (16k?) used by AMSDOS. I don't mean ROM expansions here.

Is there any modern, compatible chip i could use like a eeprom ? Or can't I avoid using a one-time-only PROM or (even worse) a windowed EPROM ?

There is a 28c256 to 27c256 adapter on github, see aDIPters. May be suitable as a 23256 replacement.

But I must stress, I have not built or used the project. However, I would be interested to see if it is suitable.

[orzel]

There is a 28c256 to 27c256 adapter on github, see aDIPters. May be suitable as a 23256 replacement.

So basically, "no".
There's really not much difference between 28c256 and 27c256 pinouts... I wonder if they did it on purpose.

Thanks for the link, might give it a try. It's nicely done.

[Rabs]

There is a 28c256 to 27c256 adapter on github, see aDIPters. May be suitable as a 23256 replacement.

Thanks for the link, might give it a try. It's nicely done.

I may give it a try myself, but generally I don't mind using the EPROMs as I have a UV EPROM Eraser.

The PCB is available on PCBWay, see 28C256 to 27C256 and I can see the 28C256 SOIC in stock on DigiKey, see AT28C256-15SU

[orzel]

What about flash chips like  AT29C256 ? they are not easily sourced, but still a lot more recent than amstrad-period ROMs. They are 5v and the pinout seems ok... ?