Mac II + Turbo 040 help

[ObeyDaleks]

So here's an update. I flashed new 4.11 and 4.01 ROMs, and neither of them worked. Both of them produced a chime, but no video and the computer froze. I found a version 3.07 dump as well but don't have any more eproms, so I had to order a few more. My guess is it's not a ROM issue but rather the hardware is not capable of supporting Mac II. I read somewhere that the first release was exclusively for the IIci, which is probably what this card is. I will try the 3.07 rom, as well as any older version I am able to find.

Interestingly, the programmer was unable to read the original ROM from the card (some error indicating a pin issue), which is a mystery since the computer was able to POST with that ROM installed.

I might be doing something wrong, this is the first time I've used a programmer. But it's so straightforward, I'm not sure what I could be doing wrong. I literally pick the eprom model from the list (AT27010 PLCC32), load the rom dump, then write to the eprom. It writes and verifies. It even has a feature to verify that the eprom matches the rom dump.

 

[Phipli]

but don't have any more eproms, so I had to order a few more.

You should be able to just erase and reflash them?

 

[Phipli]

Interestingly, the programmer was unable to read the original ROM from the card (some error indicating a pin issue), which is a mystery since the computer was able to POST with that ROM installed.

This usually means you have the wrong brand / model selected, or that you need to reseat it in the adapter. The adapters are terrible. I find they work best if the chip isn't quite pushed down all the way.

 

[ObeyDaleks]

This usually means you have the wrong brand / model selected, or that you need to reseat it in the adapter. The adapters are terrible. I find they work best if the chip isn't quite pushed down all the way.

Ok so I figured it out. It had some sort of ID check as part of the read process, and it was failing. So I just disabled it and it read the original ROM fine. I saved it off to a file (not sure how to determine the version).

 

[ObeyDaleks]

You should be able to just erase and reflash them?

The eproms I have, which match the original rom (AT27C010) are OTP (one-time programmable). They cannot be erased or overwritten.

 

[Phipli]

The eproms I have, which match the original rom (AT27C010) are OTP (one-time programmable). They cannot be erased or overwritten.

Grab yourself a AT29C010 instead.

 

[ObeyDaleks]

So I got the new EPROMs and tried flashing 3.07 but unfortunately it didn’t work either. I guess if I ever get a IIci, I might try it there to see whether it’s just a compatibility issue with the Mac II or the card is just broken.

Since I can’t get this one to work, I got myself a 50Mhz Daystar PowerCache and it works great with the adapter. I would guess that it gives me a similar performance boost as that 33Mhz Turbo 040.