Macintosh SE EEPROM to ROM adapter

[Wulf Wulf]

I do not know, if it helps, but in this thread (last post) there is another adapter (for one 27C010):

Macintosh SE broken ROM LOW chip

Hi all, I have a Mac SE showing a barcode-like pattern: A friend of mine has the same computer, so we swapped parts until we found the culprit: the 342-0353-A (rom low) chip. I got the BIN image on the web (64 kB), but I don't know if I can use a 27c512 eprom as direct replacement or not; do...

forum.vcfed.org

There are two 4.7kOhm Resistors used to connect the 5V to VPP, PGM and OE.
I think that this is used in the same way in the above adapter.

Thanks for the clue.

 

[Wulf Wulf]

Try asking on Tinker Different, Kai hangs out over there these days.

I'll definitely look into that option. Thanks!

 

[TheBurgerKing]

Has anyone successfully replicated the HI/LO roms using this adapter? Also, was the value of the resistor network (RN1) ever determined?

 

[Daniël]

Has anyone successfully replicated the HI/LO roms using this adapter? Also, was the value of the resistor network (RN1) ever determined?

As mentioned before, Kai doesn't browse this forum anymore, from what we know, so you sadly won't be likely to find the answer here. He's active over on https://tinkerdifferent.com, so it might be best to try and contact him there, or to start a thread about it.

 

[xporadio]

RN1 = 1K

 

[TheBurgerKing]

RN1 = 1K

Thank you. My boards should be here this week. My plan is to test the boards this weekend.

 

[TheBurgerKing]

I built a few of these last night and couldnt get them to work. All I get is a garbled screen. I tried several different values for the resistor arrays, same result. I know the EPROMS are good because they work in a modified socket I made. Has anyone implemented this solution successfully? If so, I am all for some pointers.