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I do recall seeing that SCSI drive case before. And after a little Googling... PocketPro ad at left on page 31 ($29.95 without adapter, $54.95 with): https://www.wap.org/journal/showcase/washingtonapplepijournal1996v18no4.pdf PocketPro 25S ad at right on page 95 ($29.95 without adapter...

It might be possible to find. It's just not high priority for me right now since I have other good and working 1MB SIMMs. But I can come back to this at anytime, get a new chip and see if that works. Pretty amazing animated GIF you made there! That must have taken some serious time to...

EBAY shows four 1MB SIMMs for a good price until shipping to Japan is added https://www.ebay.com/itm/153233852691 So I don't really know.

Thank you very much! I will do that test when I have time, but for now, I humbly wish to thank you for educating me on the proper way to diagnose 30-pin RAM SIMMs down to the chip level. Amazing!

I confirmed that pins 1 & 25 are connected to each other on all 8 chips. I then tested between SIMM pad 23 and pin 1 of each chip and found that only the second IC from the right, as shown below, is connected to pad 23.

@YMK I apologize. I was busy and hadn't looked at the LC321000-10 datasheet (SMD chip version) as I should have. But extracting the relevant chip diagram from the correct SMD version datasheet shows this... Din = pin 1 Dout = pin 25 So the 2 pieces of advice you gave me were: You should...

@YMK To understand how to test "D6" I was looking for a schematic of 8-chip 30-pin SIMMs. I only found this one, which doesn't have 8 chips... SOURCE: https://alexandrugroza.ro/microelectronics/system-design/4mx9-simm/index.html The only useful thing the above schematic tells me is that...

Thank you for the specific guidance! I appreciate it. I've extracted the content you spoke of here... It is basically the same content as what @retr01 posted here, and what is shown on this website. It was that same info I consulted when putting together my opening post. Simply put, that...

@Crutch , could you please provide an exact link to the "THINK Reference" you are referring to? The best I can find on Macintosh Garden is Symantec THINK C 6.0.1, but when I open "THINK Reference" on "Development.img" in Mini vMac, I only see this... Now THAT is the speedy testing tip I was...

Kai, thank you for your reply. I gleaned the Rear = Bank A, Front = Bank B info from this Low End Mac article. (6th paragraph from the top) I know for a fact which SIMM is bad because I put it into different slots with 3 other known-good SIMMs and the Sad Mac codes changed in accordance to the...

I've been testing my inventory of 1MB RAM SIMMs using my Mac SE Reloaded machine, and with one particular set of SIMMs, I get a Sad Mac at cold boot showing these 2 lines: 00000004 <— "Bank A" 00004000 <— Failed bits... AABBCCDD AA = bits 31-24 BB = bits 23-16 CC = bits 15-8 DD = bits 7-0...

MFM encoding in combination with an ST-412 interface. Details... https://en.wikipedia.org/wiki/ST506/ST412

It seems everyone now understands the HyperDrive I show is not SCSI, I should add that at 7:14 in my GCC HyperDrive 10 video, I show it is an ST-412 interface (instead of SCSI). That interface requires two cables. Also, as I point out in that same video, the HyperDrive was on the market at the...

Not sure. It was like that when I got it. But it probably can be straightened without issue. Now that I know the chip is pre-programmed, I need to build the board, then test it. I can then report back here as to the result.

Good question. You are referring to this ADB chip used by Kai's PCB... @Kai Robinson, from what board were these chips extracted? (The two in the photo above are the 2 you kindly shipped to me.)

Kai, thank you for that important clarification, especially because your Github page here does not clearly state the chips that you need must be special pre-programmed chips that are to be acquired from the place like UT source. In an older PM, you had previously told me the following... But...

Explained in green at the bottom of page 4 in my BOM here. I have not built or tested one of those boards because I have never bought the required programmer. I assume @Kai Robinson has programmed and tested at least one of them though.

I actually did some EBAY searching. For a scratched up 2G unit which nobody wants, you'll pay about US$80. For a more pristine unit that is also functional, you'll pay US$250. But if I had a functional unit, I'd probably keep it in a case or drawer mostly, whipping it out to show people when...

My preference too "if and only if" it arrives intact. Knowing how these items get kicked around, it probably wouldn't unless they spend a lot more on packing material to ensure the glass arrives in a pristine condition.

I take it you have the RAM chips with the Apple logo printed on them? Those seem to be the worst in terms of reliability for some reason.