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Kai Robinson

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Everything posted by Kai Robinson

  1. BOMARC SE SCHEMATICS!!!!! :o Mac-SE-PS-KBD-Mouse.zip Mac-SE-MB-video (1).zip
  2. @maceffects did you flood the socket area with flux? You need a temp of around 420 degrees centigrade on a desoldering gun. To remove cleanly, you need to add fresh solder to the pins or holes left behind, you NEED flux so it flows nicely, then it's a matter of using the desoldering gun on the pads. Max of a second on the pad, tip flat, not at an angle, then wiggle a little then press the trigger. Right now, I'd advise re adding solder to the socket area and continuity test, patch any broken traces later.
  3. Bonjour Tim! Ca va? J'habite en Bretagne pour douze ans, pres de St. Malo Those PDF's are GREAT! The schematics are especially valuable - do you have schematics of the whole system? @quorten has been vectorizing the only existing page of the schematics, and page 2/3 would be invaluable! :o Many Thanks, Kai
  4. Right so today has been interesting... First thing i checked was the BBU and the ROMs from my board, using a spare board that @cheesestraws sent me a few weeks back - they checked out - even the mac classic BBU was tested as working - so yes, confirmed, the Classic BBU is identical to the SE's, in functionality and pinout. Then i bridged the /AS to A8 bridge and voila - bus traffic appeared! However that was about the size of it - no magic beep, still. Then i looked at the 74F257 spot...err...oops. I'd only tacked in the DIP sockets, and not connected the rest So, wit
  5. I think i have the answer!!!! /AS was cross connected to A8 on the PDS Slot -(anyone with the sprint layout file can check this) one track intersected a little too close - should be possible to cut the trace and patch it around - but this looks promising - i was wondering why there was no activity on any of the buses! I'll try this fix in the morning - but for now the missus is groaning at me to turn the lights off and come to bed...and we all know that happy wife = happy life
  6. @mogs Get the PLCC nozzle and some AMTECH RMA233 flux - it'll make things a lot simpler. I'll await your inner layers idea - consider my curiosity suitably piqued
  7. In theory you could remove it all, then rely on the SIMM only...but i wouldnt confirm that theory. I'd still get an SOJ stencil and replace the damaged chip or chips. To diagnose, you'll need an oscilloscope and/or a logic probe. You want to check each pin of the address and data bus - see if the waveform looks solid, ie ___/‾‾‾\__/‾‾‾\___ Rather than ___/WWNLS\__{Y}_V\ (it's hard to draw in ascii - but if you look at Adrian Black's TI/99A repair video's you should get an idea.
  8. Easiest way is to examine the address and data bus with it powered on - if one line looks squiffy, you can usually pin it down to a single chip. These can be replaced easily enough by any 4Mb x 4 DRAM chips - i recommend the Toshiba TC514400's - as they're cheap and plentiful. You'll need a decent hot air station, flux, tinfoil, kapton tape and a bit of practice. I also recommend a SOJ-26 solder stencil, so you can use solder paste rather than drag soldering, although that's an option too, using a K-Tip on a decent iron.
  9. I'm happy to give up a handful of SWIMs to anyone that wants to reverse engineer them
  10. Uploading this, for those that might be interested in a 68020 accelerator design. Wireless World, July 1987 - 68020 cache design.pdf
  11. Latest acquisitions! GENUINE NoS 3430045A's (Sony SND Chip) GENUINE NoS 3440042B's (RTC Chip for SE & SE/30's) Refurbished, used 344-0062A's (SWIM Chip, Harris branded with 1990 Date Codes) - These look to be genuine, just the tops have been skimmed and re-printed - not a cheap job, these won't rub off with alcohol. So if anyone needs one - ping me a DM,
  12. The PCB itself - no. The GAL's on the board? Yes, unless you're lucky and they're 16V8's in combinatorial logic mode. Else you'll have to deconstruct the GAL logic using a logic analyser.
  13. Top and bottom layers provisionally done Now, the inner layers should be just ground and power - but i fully expect there to be some surprises. I know there's talk of these being 6-layer boards, but honestly, these are cost reduced SE's with no PDS slot and only 1 ADB, the schematic isn't all that complicated and that's the other thing, we have the schematic! Would anyone like to take a look at the Sprint Layout file so far?
  14. @pinto_guy do you have any information on the screens used, or the interface that connected to the LB in these machines?
  15. I've known about the TTL output for a while but...i thought the output signal would be useless for TFT's - do you have any more information?
  16. I read it parsing the text through google - was accurate enough to understand!
  17. So to bypass the analogue board/psu issue and reduce the incident of electrocution, i have made my own PSU for the board tests out of a Meanwell RT-65, some 16-gauge wire, some spade terminals, ring terminals, a DPST switch and a 3-pin 1 amp plug Works first time! Although i maybe should have used 18-gauge wire, but squeezing them into the molex terminals was hard enough... So now all i need is an enclosure - open chassis aren't my favourite thing in the world. I also crimped a molex KK plug for a 64 ohm speaker, so i can have audio confirmation of beeps at startup
  18. Thanks to the BOMARC Schematics - most of the pinouts are mapped for a lot of these ASICs, it's just a matter of tallying pin vs function, and the painstaking process of writing them down!
  19. @anthon - Thanks! It's still a WIP - still not sure what could be wrong at this stage, but i have my eye on the RESET circuit... @quorten, @asicsolutions - This might help you with the BBU - while categorising the ASIC Customs and making pinouts for them, i decided to do the BBU and colour code it all: https://docs.google.com/spreadsheets/d/1NDIA5orTwraRmOUgzrKxWYXcf2AXdULkdwUm020HdXI/edit#gid=1403563772
  20. Here's one to start with - runs a 68000 at 16MHz, includes 16K of Cache and a 68881 FPU... https://drive.google.com/file/d/1Op7TzK1pxRjqcT68MoZE1G4HNkS5GJNe/view?usp=sharing All the GAL equations and schematics included.
  21. Would you mind sharing the 1200dpi scans of the inner layers with me, so i can try for a 1:1 layout? VRAM is easily available on UTSource as NoS, as is DRAM for making 30-pin SIMM's, i have 50x PCB's for 30-pin SIMM construction, and new PE Connectors SIMM Sockets.
  22. ADB XCVR available! These work in: Classic, II, IIx, IIcx, IIci, SE/30 & Quadra 700
  23. @techknight SE/30 is on the bench now, i can't help myself! @Bolle did you manage to image the inner layers?
  24. @rplacd actually - the most beneficial thing would be to strip and sand the board so the inner layers are visible, and scan them! I live in a shared flat and have no 'outside area' that's suitable for it, really. At the end of Sunday - this is how much i've managed to get done of the top layer;
  25. For now this is mostly going to be a placeholder, until the SE boards are finished, but as the title explains, this is designed to save as many Mac Classics as possible. So many have died thanks to the stupid PRAM battery on the board. These are 4-layer PCB's with a mix of through hole and SMD component. You will need at bare minimum, a soldering iron, hot air soldering station, desoldering station and a decent selection of hand tools. So - how do you reproduce a PCB? First, get a Mac Classic PCB - in my case a 'dead' board from Mr Adrian Black! Then, you get to work d
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