Search results

I'm not sure that page is correct. Years ago I crawled through the Apple Developer Notes for those machines in detail. I'm not going to redo that work, but my conclusion at the time was that the 7200's list of supported memory chips/DIMM configurations suggested that a 256 MB DIMM could be...

Apple's talk about megabits per chip is detailed talk about the exact way the machine addresses memory. Without understanding all about RAS and CAS and how memory is addressed, that's not going to mean much to you. I typed a very detailed explanation once. I have no idea where. Probably...

Four ANS Macintosh ROMs ready to test. Will get them to ClassicHasClass soon.

Thank you. That's what I needed to know. The need for swapping order/label is not an error, so much as an artifact of historical labeling. There's probably something that needs to be changed to make it more sensible, but I'm not sure what at this point. Ah, here's what happened. My...

Checking: You left the extracts in the order that kansas_deinterleave produced? In other words, U1 = U1, U2 =U2, U3=U3 and U4 = U4? I must swap U2 and U3 (artifact of labeling on circuit board) and I want to confirm that you did not pre-swap them. It seems unlikely, but a careful reading...

Enabling the use of WE was almost an after thought in the lay out. The _WE pins are all hard wired high. I think I left clear traces between _WE and Vss, but they would have to be physically cut and then the line to the DIMM _WE pins connected with resistors and I think in one case a jumper...

ANS 2.0 means the first one above, "ANS Deinterleaved.zip"? That is correct. Actually, I made a provision to enable the WE pin to all of the chips from the WE pin(s) on the DIMM. It's been 20 years since I laid the thing out. IIRC, connecting them requires installing a couple of 0 ohm...

Heh. Rob's stuff seems to still be online: http://synack.net/~bbraun/kansas/ Original files for Kansas ROM dump and file reads directly from ROM chips are at https://sphinxgroup.org/Firmware/

Explanation is in the thread linked above. I'm not sure if Rob's deinterleaver is still downloadable from links in that thread, but I believe it is here: https://sphinxgroup.org/Firmware/PEx/Deinterleaver%20Utility%20and%20Examples/ What it boils down to is that one divides the ROM dump...

Heh, Rob Braun wrote the decoder script that converts ROM dumps into four files to be programmed into x16 chips on a module... https://68kmla.org/bb/threads/pex-rom-project.23568/post-269617

I don't know how I never noticed this thread until now. Visiting here too seldom. I can make copies of those ROMs, but will need some help processing the dumps to get them ready. I still have thirteen blank ROM circuit boards and hundreds of flash chips. Process the dumps. Program them...

There are four things that come to mind when shopping for that kind of part: 1) Is the shop reputable. IOW, will you get the part that is listed. 2) Is it the correct part number. In this case, yes, it is. 3)* Is the part in the correct package. The part is actually the tiny silicon...

That's them. They still have the 64 pin SIMM socket for less than $2. However, the Quadra connector, 8817-140-170LH no longer has a search result. Back in 2021 there was pricing (don't know about stock) here...

It may not be power drain per se. It may be that the memory controller does not have/use enough drive strength for the number of chips connected to the bus. The current provided on the address/control lines may be too low. But... It seems to me that the number of chips with 4 X 128 MB...

A bit cheaper at under $2, but I don't remember how easy or difficult ordering is. It's been too long: https://www.connectorpeople.com/Connector/TYCO-AMP-TE_CONNECTIVITY/8/822019-2

Generally, one SCSI jumper represents '1', one represent '2' and one represents '4'. The SCSI ID is the sum of the jumpered values. For none jumpered, one gets '0'.

A lot more work, but might it be possible to work backwards through the firmware? Find the references to the known register in the LC475 firmware. Identify the surrounding code, used to set clock speed. Then search for similar code in the Q/LC/P 630 firmware and then look at which register...

Kind of you. I think regular work outs is the way forward. I'm used to being able to step out the door and just run 4 miles without giving it a lot of thought, so current condition is weird, but perhaps inevitable given weight gain, age and intense sedentary desk jobs. When I was much...

Still in yard work mode, although when I posted that in Sept. I wasn't getting a lot done. Did more a few weeks ago until we settled into deep freeze for a week. I've been weak for a couple of years. Don't know if I convalesced too long after lung pudding/covid and knee surgery in 2022, or...

All the PPC601 machines that ran at 100MHz or over came with a Peltier equipped heat sink with those four clips. Shreve Systems used to sell them for some absurd price like 10 for $20 or some such. I wish I'd picked up a box at the time, I think. That said, I did some experiments a couple of...