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Macintosh SE/30 logicboard recreation (thread revival)

Posted by: Cam on 2023-03-22 13:42:11

Don't know if anyone in Canada is looking for a source of 64 pin SIMM sockets, but I ordered and installed these https://www.componentonline.com/product/426B-64-1A/0015821104 and they seem to fit fine, AND have metal release tabs.
The company has a minimum $ order ($30 CDN?) and I'm not sure if they ship internationally.
Shipping was very fast, but then again they're not very far from me; your experience may differ.

Back to troubleshooting . . .

Posted by: alectrona6400 on 2023-04-22 15:48:29

Where is a good place to buy a PCB like this? I have an SE/30 motherboard that's had some damaged traces and pads from neglect due to (very) bad caps and I'd like to save it with a nice fresh board.

Posted by: Daniël on 2023-04-23 04:06:28

Where is a good place to buy a PCB like this? I have an SE/30 motherboard that's had some damaged traces and pads from neglect due to (very) bad caps and I'd like to save it with a nice fresh board.

JLCPCB and PCBWay are the "big ones" for hobbyist PCB manufacturing, so to speak. I would just go for whichever one could provide it the cheapest, which tends to be JLCPCB in my experience. There are other Chinese PCB manufacturers, as well as Western ones like OSHPark, but they'll likely be much more expensive.

Do note that practically all PCB manufacturers have a minimum order quantity of 5 PCBs. So if you just want one, you'll still get four blanks. You might be able to find people to do a group buy with, or could try selling the other boards to fellow enthusiasts on the forum through the Trading Post.

Posted by: WillJac on 2023-04-26 06:18:00

Where is a good place to buy a PCB like this? I have an SE/30 motherboard that's had some damaged traces and pads from neglect due to (very) bad caps and I'd like to save it with a nice fresh board.

I can probably provide you with one. DM me and we can discuss.

Posted by: storhemulen on 2023-05-07 11:49:59

Has anyone been able to use the PLCC for the rom instead of the SIMM? No matter what we do, we can’t get it to boot. With a simm in place it boots right away.

If anyone has had success with these, I’d be very grateful for some rom files so I can compare. Byte swap has been done as per instructions.

Did you ever get it to work with PLCC ROMs? I can't get it to boot either.

Posted by: Jockelill on 2023-05-07 12:38:40

Yes we did, needs to write the 64k file to each rom.

Posted by: storhemulen on 2023-05-07 14:32:26

Yes we did, needs to write the 64k file to each rom.

Hmm. Does not compute. 😀

1. Swap data bytes, save to new file
2. Split into 4 parts
3. First part goes in RU1

Correct?

Posted by: storhemulen on 2023-05-07 22:31:13

Hmm. Does not compute. 😀

1. Swap data bytes, save to new file
2. Split into 4 parts
3. First part goes in RU1

Correct?

Answering myself here...

Should have checked the github page more carefully. Then I would have noticed the files already prepared in the "ROMs" section. Guess I should get the board working with those first and then try to flash my own files.

Since I am using 29F010 flash which holds 128 kbyte, this means I have to pad each 64 kbyte file with itself, right?

cat SE30stockU1.bin.swapped SE30stockU1.bin.swapped > SE30stockU1.bin.swapped_doubled

Posted by: storhemulen on 2023-05-08 02:09:22

Sorry for spamming, really keen to get this working... 😎

From Bolle's github: "...stock SE/30 ROM split up in to four files and bitswapped".
I was raving about swapping bytes, but I guess the correct thing to do is to swap each bit so that bit 31 becomes bit 0, bit 30 is bit 1 and so on.

Let's say I have a stock ROM file (checksum 97221136) called orig.bin. Would below scheme work?

First splitting the original into 4 parts:

srec_cat orig.bin -binary -split 4 0 -o rom0.bin -binary
srec_cat orig.bin -binary -split 4 1 -o rom1.bin -binary
srec_cat orig.bin -binary -split 4 2 -o rom2.bin -binary
srec_cat orig.bin -binary -split 4 3 -o rom3.bin -binary

Then using a 4 byte width for reversing all 32 bits of data:

srec_cat rom0.bin -binary -bit_reverse 4 -o rom0_bitreversed.bin -binary
srec_cat rom1.bin -binary -bit_reverse 4 -o rom1_bitreversed.bin -binary
srec_cat rom2.bin -binary -bit_reverse 4 -o rom2_bitreversed.bin -binary
srec_cat rom3.bin -binary -bit_reverse 4 -o rom3_bitreversed.bin -binary

Posted by: Bolle on 2023-05-08 02:45:41

First splitting the original into 4 parts:

srec_cat orig.bin -binary -split 4 0 -o rom0.bin -binary
srec_cat orig.bin -binary -split 4 1 -o rom1.bin -binary
srec_cat orig.bin -binary -split 4 2 -o rom2.bin -binary
srec_cat orig.bin -binary -split 4 3 -o rom3.bin -binary

Correct so far.

When reversing the resulting split files leave out the 4 byte width as the split files are only 8 bits wide:

srec_cat rom0.bin -binary -bit_reverse -o rom0_bitreversed.bin -binary

Posted by: storhemulen on 2023-05-08 03:32:15

Correct so far.

When reversing the resulting split files leave out the 4 byte width as the split files are only 8 bits wide:

srec_cat rom0.bin -binary -bit_reverse -o rom0_bitreversed.bin -binary

Thank you! 🙂

Posted by: Jockelill on 2023-05-08 04:19:16

@Bolle beat me to it, but the above solution works I can confirm. And yes, the ones on Github can be flashed directly to the roms.

Posted by: storhemulen on 2023-05-08 10:18:31

It's alive, kind of! My monitor can not sync the 22 kHz signal correctly, but it's enough to tell that I have a mouse pointer that I can move.

Most of the components mounted, but no SCSI or floppy controller yet.

Hooked the board up via VGA and a small adapter board.

Time to mount the remaining components and possibly get a custom ROM flashed.

Posted by: joshc on 2023-05-08 10:48:03

It's alive, kind of! My monitor can not sync the 22 kHz signal correctly, but it's enough to tell that I have a mouse pointer that I can move.

View attachment 56297

Most of the components mounted, but no SCSI or floppy controller yet.
View attachment 56298

Hooked the board up via VGA and a small adapter board.
View attachment 56299

Time to mount the remaining components and possibly get a custom ROM flashed.

Rounded corners and a cursor is good news 🙂 Nice one.

Posted by: croissantking on 2023-05-08 12:01:20

Being able to use PLCC chips for the ROM will become increasingly important with the scarce availability of 64-pin sockets.

Posted by: Phipli on 2023-05-08 12:08:44

Hooked the board up via VGA and a small adapter board.

Phew! I was about to panic and tell you to attenuate that video signal 🙂

Posted by: storhemulen on 2023-05-08 22:54:26

Phew! I was about to panic and tell you to attenuate that video signal 🙂

Not to worry. The signal out from the adapter board is below 1 Vp-p. I built the little board here:

Compact Mac video adapter « waveguide.se

[img=mac-se-video-bmva.jpg] For many years I have had an old Macintosh SE logic board that was scrapped out from an old Apple repair shop. Someone had broken the SIMM sockets at some point by snapping the retaining clips at the ends. A common problem u...

www.waveguide.se

Posted by: storhemulen on 2023-05-11 08:27:04

A cheerful chime and a moveable pointer on the CRT, which means a little step further for this Reloaded board.

No disk with question mark though. Maybe this is normal behaviour if both scsi and floppy controllers are missing?
We'll see when they are properly mounted.

Posted by: joshc on 2023-05-11 08:48:33

Maybe this is normal behaviour if both scsi and floppy controllers are missing?
We'll see when they are properly mounted.

Yeah that's why.

Posted by: ace192 on 2023-05-14 03:15:53

This is a great project! How many different logic boards have been recreated so far, just the SE/30?

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