68kMLA Classic Interface

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Wanted - Macintosh SE Schematic Pages 1&2 (not SE/30)
Posted by: Kai Robinson on 2020-06-26 06:45:15 So - in my efforts to reverse engineer the Mac SE logic board - i've found a few alternatives to Apple's 'custom' chips. I managed to get (read:forcibly eject) the equations from the GLU chip (it's a 16L8), but the /OE data is a little OTT. If anyone has either of these pages of the SE Schematic that don't look like they were drawn on an etch-a-sketch and scanned in using a hand scanner by someone coming off a meth addition, it'd be much appreciated. Or even if you have page 2 - i might be able to do something with it at any rate! Failing that - the signal names on the GLU Chip would be useful, as i only have the generic pin config for a 16L8. Many Thanks, Kai
Posted by: maceffects on 2020-06-26 07:45:31 I can't speak for anyone else, but this sounds very exciting! Where would such schematics be? I have the Inside Macintosh books which I think are online with PDFs as well. I don't recall seeing them in there, but I have tons of hardware books of that era.
Posted by: Kai Robinson on 2020-06-27 23:29:28 OK - so - first you desolder literally everything on the board, and i mean everything. Then you scan the board at 800 or 1200dpi, load the image into Sprint Layout - draw the outline of the board....then the ground plane, then add the component legs or pads, then join the dots, with traces - it's almost therapeutic! Then sprint kicks out a set of gerbers - voila, 1:1 cloned PCB, which is then sent off to PCBWay/SeedStudio/JLCPCB etc for manufacture. Then once the board is built up and tested and verified, i'd sell them for cost + 10% to cover the costs of the initial project, then open source it on github after i've recouped the costs involved.
Posted by: Kai Robinson on 2020-06-29 06:18:51 Am i allowed to bump this? I'm happy to pay for a set of bomarc ones, if thats even still an option.
Posted by: maceffects on 2020-06-29 06:26:53 This is the best I have in my collection of schematics. This is probably the one you have. I don't recall seeing a Bormarc SE but I could (hopefully) be wrong.
Posted by: Kai Robinson on 2020-06-29 07:01:07 Yep, that’s the only one that I have. I’m missing page 2, too.
Posted by: Trash80toHP_Mini on 2020-06-29 10:54:57 There's no SE listed in Uniserver's offerings, but the Classic is listed if that might be of help" I've got Apple's 512K schematic if that might be useful from the other end of the Compact lineup?
Posted by: Kai Robinson on 2020-06-29 18:07:49 Unfortunately both systems are so very different from either the Plus or the classic, VIA vs TPI, ADB, different custom logic etc. I ideally need to write down the pinout for the BBU, GLU & ADB Chips.
Posted by: Trash80toHP_Mini on 2020-07-09 09:28:44 I have pp.1-8 of the SE. I could use just the one(?) SIMM page of the BOMARC SE/30 set. Apple's stuff I can't grok, hoping the SE/30 scheme is similar enough to my IIsi set to act as a rosetta page.
Posted by: Steven on 2021-02-06 06:43:28 Guys, i need a little help with my mac se fdhd. i opened it up and the battery made a little mess. Although it was still working i found that against the battery holder there was a ceramic capacitor which lay loose because of the corosion. it says A5E 104 Z5B 537 I found out it’s a 100 nF ceramic cap but not sure about the voltage though and whatever is written on it. i do have a 100 nf ceramic cap which is 25 volts. Could anyone give me the right values of this cap? i would love to have it complete again. thanks in advance. steven
Posted by: Kai Robinson on 2021-02-06 07:46:05 Hi @Steven - Can you post a pic of the location of the cap? I have the full schematic and BOM available.
Posted by: Steven on 2021-02-06 10:41:41 Hi Kai, The cap is just to the left of the battery holder. as you can see c10 is out.
Posted by: Steven on 2021-02-06 10:42:17 It is a small yellow one like the other ones on the board.
Posted by: Kai Robinson on 2021-02-07 02:35:22 C10 is a 100nf decoupling capacitor.
Posted by: Kai Robinson on 2021-02-07 02:35:55 BTW if you want a new battery holder, i have a link to where i get them.
Posted by: Steven on 2021-02-07 09:11:53 C10 is a 100nf decoupling capacitor. Thank you Kai, does it say what voltage it should be able to handle? Or isn’t that of utmost importance? should 25v do?
Posted by: Steven on 2021-02-07 09:12:47 BTW if you want a new battery holder, i have a link to where i get them. Appreciated, got one out of an old 7300/200.
Posted by: Kai Robinson on 2021-02-07 09:16:11 Thank you Kai, does it say what voltage it should be able to handle? Or isn’t that of utmost importance? should 25v do? 25vdc is more than enough, it's only decoupling the +5v rail.
Posted by: Steven on 2021-02-07 09:56:22 25vdc is more than enough, it's only decoupling the +5v rail.
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