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About Compgeke

  • Birthday 01/06/1997

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    Fairfield, California

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  1. Maybe it's been a while but we haven't have forgotten you! The PCB for the Macintosh IIc* is finished footprint wise, and I think we've got the components nailed down too. So, onwards with findings: 1.) ATX seems to not be ATX 100% of the time. By that I mean we've been thinking @blusnowkitty's IIsi had issues this whole time but that's not the case - it's my ATX PSU I was using. It seems some ATX PSUs are more forgiving to rapid on/off. The other one wouldn't reset right away so the system would shut down right. The new one wasn't happy that there wasn't an immediate drop in the ATX_ON signal and reset right away. The fix was to up the resistor for the /pfw line which now works perfectly. Even better is that change didn't break compatibility with the Quadra 650 - need to test IIcx and IIci later today. Here it is with those changes in the Quadra 650. Line is still high enough to not mess anything up - works fine! I've also done some load testing with the final version of the board! Full tilt 33 MHz '040, three 24-bit video cards and a spinning hard drive still keeps it above 5V on the board output - and that's with 1oz poverty copper.
  2. More update: For get the whole voltage thing for now as I've now got two IIsi s confirmed working. Got a 2nd recapped and it's all rainbows and sunshine. And here's a video of it working:
  3. Compgeke

    Recommended system extensions?

    That's just Mac OS being Mac OS. Anything prior to OS X does that really.
  4. I got the IIsi board today, got it recapped and got it working. Some fun discoveries though. To start with, the IIsi is possibly special. By that I mean it's /pfw voltage for button press seems to be a bit different. Lemme make a list. IIsi I have here: 3.4v @blusnowkitty 's IIsi: 4.4v IIci: 5.1v IIcx: 5.1v Q650: 5.1v. Notice a slight difference? I do. With the good news - the transistor board is working fine for me. As is the 74HCT04 and zero resistor setup. The bad news - why are the IIsi s giving different readings. Why is the one with the lower readings working and the higher not. I need to probe more IIsi for "wtf is going on" - see which is the anomaly. Good news is there's someone else close to me with a IIsi who also needs some help with another machine. I'll see if I can get a reading off theirs.
  5. Compgeke

    040 Recommendations?

    Quadra 650 for sure. The cases are pretty reasonable despite being ugly. They run at 33 MHz and are (usually) a full '040. There's no reason to pay the extra cost for something like an 840 for an extra 7 MHz. As a bonus only the power supplies need recapped - the motherboards are solid caps from the factory. 800 is the same machine but in a worse case. They're more prone to breaking.
  6. To expand a bit, the LC is a different thing all together. Physically this particular board won't fit within the LC PSU shell. The LC also doesn't require a /pfw inversion (they don't support soft power) and it uses -5V rather than -12V. We've talked about it and even have some plans however that's an "After this one" project.
  7. Of course, if you're working with other people I'd recommend using KiKad There's Eagle can be a bit special when exporting to work with other programs and break silkscreen text placement and those kind of goodies. That, and you'll lose all the device footprints and just get holes in general. Not really something heavily needed and the exclusion enables it to fit in a IIsi easier. The 10 pin connector has a fairly snug fit (and really, you could get away with no standoffs) so as a good measure one's thrown on the other side. I ran some traces through there on the last (that should be final - pending IIsi testing) revision to allow for a cleaner layout and more space for the 5V and ground planes. I Here's the board we have for testing at the moment (first version with planes). It does work (I can pull a fair amount of current) but I'd like better. Here's the current setup, the one that cut out that top standoff hole. A slight modification on the brown board gives significantly better area for the rails. And ground:
  8. A few days late, but the third version boards finally showed up. Built and working 100% no issues for me on my test systems, a IIci, IIcx and a Quadra 650. As some bonus fun, I can now load up the systems and stay (barely) within tolerance on the 5V rail using only poverty spec 1oz copper. +/- 5% (so 4.75 -> 5.25v) are generally considered acceptable ranges. On final boards they will be thicker than 1oz copper - we're just cutting a good $20/run off of testing boards by using the cheapest option. That's a 33 MHz full '040, a spinning hard drive and three 24 bit color cards. A PaintBoard Li, a Supermac Spectrum/24 PDQ and a Radius Precision Color Pro 24xk. Maybe tomorrow I'll dig up some more ram and see if I can up that draw to better match what you'd find inside a compact mac. Maybe a CD drive or something.
  9. So if we were to switch to a board using a transistor rather than the inverter (smart move really) here's something along the lines of what it'd come out like. With rearranging of the big stuff, I'm able to clear up even more space which adds even more free plane space between the power supply connectors. This means more current handling again. Any traces possible have been routed along the outside as well, rather than through the center splitting it up. Notable usability changes: I've moved the fan connectors over to the edge of the board closest to where a fan mounts in the case. During testing I'm getting tired of fighting with the connectors behind the power supply cable. I'd imagine you guys would feel the same. The LEDs are now a bit hidden when installed in the system. The good news is you'll still be able to see red or green reflecting off everything as long as we use a diffused LED. So, current handling fun: Here's the narrowest areas +5V has to pass through. I can run a IIci w/ nubus video card and spinning HDD off just one of those so this will hopefully be plenty. In theory ~75 mil * 4 with thinnest possible copper would net you ~10.5A current capability. Going to 2oz copper (the logical thing to do for a PSU board) would get you closer to the 18A mark. Ground has more area to pass through than +5V so that won't be an issue. Now, 10.5A is less than a factory IIci power supply however it's also more than a stock IIsi power supply. As far as something like +12V, it's a single 75 mil trace. With 1oz poverty copper that should be able to push 3.5A give or take. Good news is that is higher than a IIci's 2.5A or a IIsi's 0.8A on 12V.
  10. More progress tonight! I don't have the IIsi stuff or Rev 3 boards in the mail yet but I do have a transistor test setup. I can confirm everything works fine using a 2SC3904 NPN transistor and a couple resistors. It's built on a piece of solder breadboard with some machine pins soldered on so I can just plug it in the 7404 socket and pull the resistors off the PCB. Don't mind the bodge wires here - they're just making up for the Rev 2 board still be traces, easier to rework than planes. The Quadra 650 also works fine with the 74LS04 (and two 680 ohm resistors) and a 74HCT04 (with no resistors). Snowcat tried building a transistor setup for his IIsi and it's still not working - the 74HCT04 is the only one that's worked right for him. On Friday I'll have the IIsi board and I can start figuring out if it's his board or if the IIsi is weird. As a bonus, here's a video of the setup working. The first one I've actually recorded of it working. Sorry about the focus!
  11. Compgeke

    Macintosh SE Clock Battery Mod

    I had an SE with a CR2032 mod that worked for over 2 years until I sold it. Still working at the time. I'll have to see how low a Mac SE will go before losing PRAM\clock settings with a bench PSU. It'll be a lot quicker than waiting for batteries to run down.
  12. And as an alternative to that, anyone in the Bay Area or Sacramento Area have a IIsi I can borrow for testing? I'll even recap it for ya if it's not yet recapped as long as I can get something to test with .
  13. I managed to get V2 boards a day early and really early. Like check tracking when I got up and "Delivered: 6:54 AM". Electrically they work 100% fine. No need for bodge wires to make them work! 680 ohm resistors have gotten the 7404 to work properly, no matter which variant you install. You'll notice some bodge wires here - that's playing with current handling. Using just the fairly small PCB traces, I can power a Mac IIci, Supermac Spectrum/24 PDQ, RasterOps PaintBoard Li, Toby video and a single 3.5" Quantum hard drive. The voltage starts to sag quite a bit though - getting me barely ~4.7V. That's not good enough. Add a 2nd hard drive and it'd drop below 4.6V and the system won't start. The patch wires there are just for extra current handling. They're 20 gauge copper so not terribly big. With these I can run all the above plus a 2nd hard drive and still get 4.8V. The next board revision will have planes rather than small traces and should help significantly. As for the placement, the board now has the 10 pin on the opposite end of where it was before. This allows it to plug into a IIsi motherboard directly. There's plenty of clearance between it and the SCSI connector so that won't be an issue. The next thing are the LEDs. Doing some testing I had with random chinese $0.01/ea LEDs, 4.7K worked great. Of course, we have higher standards for actual stuff and called for Cree LEDs (~$0.10/ea as singles, not a huge difference). I've got some of the red Crees but they're way too bright on the 4.7K resistor off the 5VSB rail. Upping it to a 10K helps, but the LED is still retina searing bright straight on. They really don't need much current. We're going to grab some Lite-On LEDs and hopefully they'll be somewhat worse LEDs. I mean that in a good way. Picture below has Chinese Green old school tech in front, Cree in back, both on 4.7K resistors on a 5V rail. Next board will be ordered Soon(tm). It's going to move +5V and Ground to planes, clean up the resistor placement and include standoff holes. If it works fine and can handle heavy loads, it'll become the final revision. Overall, project's going good. Here's a pile of test boards I've built
  14. Compgeke

    Regressing to an earlier OS?

    In general the 9600 would be significantly slower than a G3 at most tasks. Plus it's still got SCSI and EDO ram. I'd personally look into the G4 "Sawtooth" machines myself. They can also run 8.6 and are pretty reliable. Disk I/O is plain IDE, so you can just throw in an IDE -> SATA adapter and run a 120 gig SSD or whatnot for ~$35 in parts. The RAM is standard SDRAM so upgrades/replacements are easier to source than the EDO RAM. The one downside is they don't have the mac 9 pin serial ports or ADB if those are important features. If you need a copy of the Sawtooth 8.6 CD, I've got that here. It should work on any of them.
  15. Compgeke

    SCSI to Ethernet Adapter on New Hardware

    But he's already building in disk emulation support - negating the need for a SCSI2SD.