Okay, I've read all the threads linked to. And the threads linked to by the threads that you linked to. And so on.
I had never really read all that stuff before. And I went and updated the 68kmla Wiki entry for ROM DIMM pinouts to mention that the PEX is included in Apple's "Universal" ROM module.
Any idea if Mark Crutchfield actually lives in Austin, TX, where he got his PEX? If so, and if he's willing to help, that could greatly simplify testing of the ROM DIMM. Of course, if he'd let me dissect his DIMM, that would simplify matters even more..... I can put it back together when I'm done. I just tried PMing him, so with a little luck, he'll PM me back. If not, there's an email link on his site I can try.
How can we be confident that the PEX dump is an accurate reflection of what's actually on that DIMM?
Trash80, to answer your question from almost two years ago on the Applefritter thread, I ran off about 200 ROM DIMM module circuit boards several years ago. I still have a few around and that's what I'm using for Jame's ROM. However, I can't get the sockets to work, so we're going to have to solder the chips down, and I would like to be as certain as possible that we're putting the correct code into the chips before I solder them down.
If that works, I have a few more circuit boards on hand, but even if I run out of circuit boards, we can (if we can find them) use slightly modified ROM DIMMs from Power Computing machines.
From the photos, Mark Crutchfield also has a ROM DIMM, and I wonder if his has the same contents as the DigiBarn DIMM...
I used to have sockets built just to suck the contents of a ROM DIMM to a chip programmer, but I tossed them during my last two years of house cleaning figuring I'd never use them again. I could build new ones (given sufficient 7200 logic boards to cannibalize) but it's a nightmare of wire wrap to build them. And they don't work with my Needham Programmer any way, which had a lot to do with tossing them. They do work with a BP Micro 1600 which the folks at Pioneer Data Services had, but I don't know if that door is still open or not. They may not even exist any more. It's been most of a decade...
I had never really read all that stuff before. And I went and updated the 68kmla Wiki entry for ROM DIMM pinouts to mention that the PEX is included in Apple's "Universal" ROM module.
Any idea if Mark Crutchfield actually lives in Austin, TX, where he got his PEX? If so, and if he's willing to help, that could greatly simplify testing of the ROM DIMM. Of course, if he'd let me dissect his DIMM, that would simplify matters even more..... I can put it back together when I'm done. I just tried PMing him, so with a little luck, he'll PM me back. If not, there's an email link on his site I can try.
How can we be confident that the PEX dump is an accurate reflection of what's actually on that DIMM?
Trash80, to answer your question from almost two years ago on the Applefritter thread, I ran off about 200 ROM DIMM module circuit boards several years ago. I still have a few around and that's what I'm using for Jame's ROM. However, I can't get the sockets to work, so we're going to have to solder the chips down, and I would like to be as certain as possible that we're putting the correct code into the chips before I solder them down.
If that works, I have a few more circuit boards on hand, but even if I run out of circuit boards, we can (if we can find them) use slightly modified ROM DIMMs from Power Computing machines.
From the photos, Mark Crutchfield also has a ROM DIMM, and I wonder if his has the same contents as the DigiBarn DIMM...
I used to have sockets built just to suck the contents of a ROM DIMM to a chip programmer, but I tossed them during my last two years of house cleaning figuring I'd never use them again. I could build new ones (given sufficient 7200 logic boards to cannibalize) but it's a nightmare of wire wrap to build them. And they don't work with my Needham Programmer any way, which had a lot to do with tossing them. They do work with a BP Micro 1600 which the folks at Pioneer Data Services had, but I don't know if that door is still open or not. They may not even exist any more. It's been most of a decade...