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Kai Robinson

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  1. Just the ground plane to finish off, but otherwise, done.
  2. Personally - for middle layers, i use an orbital sander and a scanner
  3. It's basically a Xerox, for PCB's - but there's no easy way to scan it in
  4. OK been chugging away with this - i'm 75% complete with the rear traces...
  5. Someone pinged me a set of KiCad redone SE/30 schematics, that's my next project after this - i'm a masochist for this stuff, i guess Anyway - i finished the top of the board just now - have a look. I've yet to finish the silkscreen etc, but electrically it's finished up top, at least.
  6. Kai Robinson

    Wanted - Macintosh SE Schematic Pages 1&2 (not SE/30)

    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.
  7. Kai Robinson

    Wanted - Macintosh SE Schematic Pages 1&2 (not SE/30)

    Yep, that’s the only one that I have. I’m missing page 2, too.
  8. Kai Robinson

    Wanted - Macintosh SE Schematic Pages 1&2 (not SE/30)

    Am i allowed to bump this? I'm happy to pay for a set of bomarc ones, if thats even still an option.
  9. I was involved in the reverse engineering of the Amiga 500+, Rob Taylor (@PeepoUK in twitter) was the man behind that idea - he since went on to do all the models of C64 board. We've got a discord server, and after watching Adrian Black's repairathon, i realised that no one had done this for a Mac...there's no reason to not do it either, so...i volunteered
  10. So - now that the board scans have been done, it's a matter of adding them into Sprint Layout Editor and then adding the components/pads, silkscreens, tracks and ground planes. So, here you can see the board view so far, after 8 hours, and what i'm seeing in sprint.
  11. Re the ATTiny85 - take a look here - i don't have any in my kit, or the means to test if it works, but if someone could, it might solve a very big problem:
  12. After scanning @ 1200dpi, and some jiggery pokery in photoshop to merge the images, you should end up with something like this. These are low-res versions of the board, in time i'll pop up the full versions.
  13. Well, this was around saving battery damaged SE boards - almost all the chips in that area aren't the customs - the BBU is in a nice PLCC socket, and the ADB, GLU & RTC are the only others that I can think of that aren't readily availble via ebay or mouser/digikey/utsource. The ADB Chip is a PIC16CR54, trying to dump the contents of that - although re-writing it shouldn't be too hard anyway. The GLU is a PAL16L8 - i've dumped the contents as a rom, parsed it through a PLD Analysis, and got a nice shiny equation list and fusemap for a new ATF16V8. The RTC is pin compatible with the ATTiny85, and i have code for that that should do the job nicely. All of this would be open source. If i could get a clear shot of the schematics for the SE that don't look like garbage, i can read the pin names, and that'll help reverse engineer that, although that should be salvaged from the original board - all the customs should be.
  14. Well, that might be possible with replacing the fixed SIMM sockets with something else - but for right now i'm not going to be modernizing or optimising the design at all - it's going to be a 1:1 reproduction. Not interested in scope creep.
  15. So - as the title explains, this is designed to save as many Mac SE's as possible. So many have died thanks to the stupid PRAM battery on the board, and with the SE being a 2-layer PCB with just through hole components, it's actually one of the easiest to save. So - how do you reproduce a PCB? First, get a Mac SE PCB - in my case a 'dead' board from eBay for €29 - thanks, random spanish man! Then, you get to work desoldering. Literally EVERYTHING. Not a single component must remain! However, 30 year old solder and my ZD-915 desoldering station caused a handful of through holes to just pull out of the board, or some traces would come up with it. I found that pre-heating the joint, with a little flux (AmTech RMA-223), would make the solder melt a lot cleaner when you use the ZD-915 desoldering gun. You must use a lot of heat, on these boards. For those joints that have been corroded, you must flood the area with flux, heat from both sides, then try and move the pin using a soldering iron (i find 420 degrees C suitable, with a standard flat tip) before trying to use the desoldering gun. Sometimes it won't always come out of the joint, in which case reflood with flux, and attack it with desolder braid. I use 2.0mm GootWick, which is fantastic stuff (thanks to Louis Rossmann for the recommendation). As part of this process, I made a list of the parts that you need to save, and the ones that you can ditch. Obviously, all the custom Apple ones are a must - the rest are either still available, or are available as new-old-stock or pulls. So - here's what you need to save: SIMM Sockets - IMPOSSIBLE TO GET - desoldering these needs HEAT as there are a lot of connections to the ground plane. Pre-heat the joints, maybe add a dab of proper Kester 63/37 eutectic LEADED solder (none of that RoHS crap), flood with flux. PDS Socket - Amphenol/AMP/AVX DIN-41612 3-row, 96-pin connector (Style-C) - Available new, but still worth reclaiming as sifting through the minute variations of parts is an arse... Inductors - probably easy enough to get new ones, but ehhh, they don't really break, and they fit fine. AM26LS30's - NLA, only available as NoS or Reclaimed AM26LS32's - Available new, but still worth reclaiming MC3488A - NLA, only available as NoS or Reclaimed RTC Chip - Custom Chip - maybe possible to clone using pin-compatible ATTiny85 ADB Chip - Apple branded PIC16CR54 - maybe possible to re-produce/clone GLU Chip - Apple branded PAL16L8 - maybe possible to re-produce/clone BBE Chip - Custom Chip NCR5830/AM58C30 SCSI Chip - NLA, only available as NoS or Reclaimed WIM/SWIM Floppy Chip - Custom Chip Hi & Lo ROM Chips - Toshiba TC531000CP MASK ROM's - Reclaim & reuse, but these are the same pinout as 27C512, but adds A16 in place of VPP pin - you can use 27C1001's on an adapter - doug brown made a similar setup with a built in ROM disk for the Mac Plus. 74LS245 - Available new, but still worth reclaiming - replace with CY74FCT245ATPC or CD74FCT245E 74F257 - Available new, but still worth reclaiming - replace with CD74ACT257E DB19 Connector - NLA, only available as NoS or Reclaimed. These are a bastard to get out cause the lugs are soldered. I found that pre-heating the joint first, filled with flux, then pressing hard into the pad with the desoldering gun, waiting til you see the solder go molten, you can often schlorp out the majority of the solder and then tidy up with wick afterwards. Passives - REPLACE ALL - use high tolerance metal film resistors & nichicon or panasonic electrolytics. Maybe try and save the PLCC Socket if you can. remove it cleanly - sometimes the pins pull out but they can be put back in if you're careful. Once you've saved all those parts, it's time to get scanning! 800 to 1200dpi on your scanner. If your scanner bed cant quite fit the whole thing on, scan one side, then rotate 180 degrees, scan, flip the image, then you can merge the images in photoshop. My scanner clips about 5mm off, so i use this method. There will be a part 2 to follow...but any questions so far?
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