exxos's Atari, Amiga & retro forum

Are there any EPROM (or EEPROM) chips compatible with the OTP dual TOS Atmel chips? Or the only way is to buy a bunch of them and flash new ones each time you want to make a change? Any affordable tool to program these chips that comes with the PLCC adapter?

I believe Hitachi do some with. HN27C4096 I think they are.

PhilC wrote: 06 Mar 2023 13:03 I believe Hitachi do some with. HN27C4096 I think they are.

I have just purchased a few of them and will check if they work as TOS-ROM in a ST536

@LarryL they will likely be too slow for the TF536 unless you use maprom

PhilC wrote: 06 Mar 2023 13:34 @LarryL they will likely be too slow for the TF536 unless you use maprom

thanks, I somehow expected that :-)
But I am using maprom and I am curious if at least that will work - lets see :-)

I have two other ROM-Boards (one for STF and one for STE) - will try this also.
But not anytime soon - too many projects in parallel ;-)

Cheers
Michael

PhilC wrote: 06 Mar 2023 13:34 @LarryL they will likely be too slow for the TF536 unless you use maprom

out of curiosity... how fast should they be?
My chips are labelled HN27C4096HCC-85, i.e. 85ns
too slow?
The AT27C4096 seems to be 55ns

@LarryL its the 55ns ones as you mentioned.

PhilC wrote: 06 Mar 2023 13:03 I believe Hitachi do some with. HN27C4096 I think they are.

Thanks. But now it seems there is no eprom programmer with the right PLCC adapter for this chip, and this requires a custom adapter :(

They all do. I had to build one for myself. The PLCC-44 adapters you get with programmers are for PIC chips.

There are some that have jumpers on the adapter that works. As mentioned above you can buy the cheap ones and bodge two wires to get it to work.

TL866 II plus by XGecu is probably de facto standard in the community. T48/T56 is newer but more expensive.