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Macintosh SE/30 logicboard recreation (thread revival)

Bolle

Well-known member
Haven't changed anything on those connectors but at least on the audio connector I see that it might be problematic.
It hasn't been a problem on the boards I ordered so far and they already must have been this way.

Looks like Eagle indeed only adds a restriction around the drilled hole on the internal layers. On the outer layers the restriction is around the actual solder pad, which is big enough to also cover the milled slot, however on the internal layers it's not.
Going to update the board files with manually added restrictions on the internal layer fills.

On the serial and ADB port mounting holes it is ok (and actually wanted) that the milled slots connect to the ground fills.
There's no VCC fill there, so no shorts will happen.
 

marciot

Well-known member
@Bolle: I have a severely damaged LC III motherboard I might eventually scrap. It has a 68030 soldered in. What form factor of chip does your motherboard use? If there is an interest in salvaging the processor from old LC IIIs, I might attempt to remove it.

Also, just curious, is it even remotely possible to upgrade a Mac Plus to SE/30 specs using a new motherboard like this, or are there other issues to contend with?
 

joshc

Well-known member
@Bolle: I have a severely damaged LC III motherboard I might eventually scrap. It has a 68030 soldered in. What form factor of chip does your motherboard use? If there is an interest in salvaging the processor from old LC IIIs, I might attempt to remove it.
The 030 in the LC III is a PLCC package, the 030 in the SE/30 is a 128 pin PGA. So as far as I know, unless there's a socketed PLCC that goes into the 128 pin PGA socket...but I also don't know if the pinout changed between them (guessing it did?).

Also, just curious, is it even remotely possible to upgrade a Mac Plus to SE/30 specs using a new motherboard like this, or are there other issues to contend with?
Nope, there is no commonality between the Plus and SE/30 beyond the 9" CRT, so you would run into numerous problems:

The chassis rails/space/dimensions for the logicboard are different.
There is no space for a PDS card to sit.
The SE/30 uses a different analog board/PSU to the Plus, so a Plus AB cannot be used with an SE/30 logicboard.
 

tevruden

Member
Nope, there is no commonality between the Plus and SE/30 beyond the 9" CRT, so you would run into numerous problems:

The chassis rails/space/dimensions for the logicboard are different.
There is no space for a PDS card to sit.
The SE/30 uses a different analog board/PSU to the Plus, so a Plus AB cannot be used with an SE/30 logicboard.

Sort of... its possible, but not really prudent.

The physical layout of the connector might be different but the signaling for the 128k / 512k / Plus / SE / SE/30 are all the same. The SE-type motherboard just drops the battery and speaker pins and adds way more grounding (Edit: It also adds -5V but only serial uses that.) It'd be trivial to create a cable that does the conversion.

If my assumption about the SE/30 logic board being the same dimensions SE motherboard is correct, it'd fit physically. There's sufficient clearance in the Plus chassis for the ram and rom SIMMs, from a quick eyeballing of the frame (doesn't look like they change the slope of the frame much.)

The difficult part would be:
  • The Mac Plus doesn't have openings on the case for ADB
  • You'd need to source the entire BOM for the SE/30 logic board including the custom apple chips
  • Can the Plus's power supply can provide sufficient current for the SE/30 motherboard?

Oh and you'd have the dubious honor of having to slide the motherboard in and out every time instead of hinging it in.
 

Daniël

Well-known member
The 030 in the LC III is a PLCC package, the 030 in the SE/30 is a 128 pin PGA. So as far as I know, unless there's a socketed PLCC that goes into the 128 pin PGA socket...but I also don't know if the pinout changed between them (guessing it did?).

Those are QFP, not PLCC. I don't think any 68k CPUs other than the original 68000 came in PLCC form.

The only way to use a QFP CPU on a PGA board, would be to do what some manufacturers did around that time, by just making a PCB with PGA pins on one side, and the QFP CPU on the other:

1646762138224.png
 

daanvdl

Active member
Does anybody know what the value is of the SMD ferrite beads on the bottom of the SE/30 board?
(L22,L20,L19,L18,L17,L16,L15,L14,L13,L12,L11,L10,L9,L8)
It is unfortunately not described on the BOM and part list :-(
 

Scott Squires

Well-known member
I take that back. It's been so long since I had those boards out; it has to have been no-socket PGA vs. socketed PGA.
 

Daimakaimura

New member
Hello everyone, I am in the process of ordering the PCB from JLCPCB and I am a bit confused. Apparently I need to specify the dimensions of the PCB. I am already uploading the zipped "Board Files" folder from the repo but the dimensions fields appear empty. Apologies if the question is stupid but it is the first time I order a PCB. Does anyone know what dimensions shall I provide when ordering it?
 

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Daniël

Well-known member
Hello everyone, I am in the process of ordering the PCB from JLCPCB and I am a bit confused. Apparently I need to specify the dimensions of the PCB. I am already uploading the zipped "Board Files" folder from the repo but the dimensions fields appear empty. Apologies if the question is stupid but it is the first time I order a PCB. Does anyone know what dimensions shall I provide when ordering it?

If the file is uploaded correctly, it should automatically fill this in. If it doesn't, ensure that the ZIP only contains the contents of the "Board Files" folder of the GitHub, and try clearing website cache or an entirely different browser if it still doesn't do so.

EDIT: I have been told JLCPCB at this moment is having issues with interpreting Gerber files, so it might just not work due to a problem on their side.
 
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Bolle

Well-known member
Board size is 222.63mm x 226.06mm

Looks like they're having issues with their Gerber parser lately. Up until last week the files I exported using a very old version of JLCs cam job files worked just fine. Had to move on to their newest job files for the gerbers I uploaded last week and they looked just fine.
Seems like they're having issues now yet again.
Board outline is in the .GKO file and it's just fine. I'd just enter the size and see what happens if I needed boards right now. (or wait and try again later if their gerber parser stops timing out while processing)
 

cheesestraws

Well-known member
I'd just enter the size and see what happens if I needed boards right now

FWIW, an (admittedly much simpler) board I ordered from them that did this came out fine when I entered the size manually. I get the feeling it's a front-end issue rather than anything more serious.
 

Franklinstein

Well-known member
I take that back. It's been so long since I had those boards out; it has to have been no-socket PGA vs. socketed PGA.
I think the only Mac board I've seen where they changed the CPU from PGA to QFP in a revision is one of the compact Mac IIs, either the cx or ci.

I may have to order one or three of these boards though since I have at least one dodgy original board that doesn't want to cooperate.
 

robin-fo

Well-known member
It‘s working! After many weeks I found some time to have a look again at my assumed-non-working replica board. As it turned out, the RAM I tried before was not compatible or broken. So when I installed the brand-new RAM sticks I received today (thanks, @Siliconinsider !!!), it booted instantly to the flashing question mark!

So my recommendation for everybody with a SE/30 with fine horizontal stripes and death chime is to try known-good RAM first! (Thanks to everybody in this forum who indicated this before)

And thank you, @Bolle , for giving my SE/30 a new lease of life!
 

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Garrett B

Well-known member
Nice work! I'm sure that was a great feeling to see it boot after troubleshooting.

Are you booting without the RTC chip installed? I thought that was necessary for proper startup, but maybe not?
 
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