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About Compgeke

  • Birthday 01/06/1997

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  1. To be honest the main design goal isn't so much for the extreme 3 Radius Rockets + Thunder IV GX 1600 extra power consumption boxes but more for the regular 'old systems. Think a IIci with a random nubus video card and maybe ethernet. You can get picoatx PSUs with 8-10A 5V rails which'll cover that use case no problem, especially if you have a SCSI2SD rather than spinning rust. For more power you're best off going with a flex atx PSU which'll have significantly beefier rails, at the expense of being more difficult to mount inside the case without either drilling some holes in the back or hacking up a bracket. Said brackets wouldn't be particularly cheap on a small scale budget, whether 3D printed or bent metal or whatnot. I don't own a sheet metal brake or a 3D printer anyway.
  2. So this one isn't quite as straight forward as the Mac II stuff is. It's mainly down to the requirement for the -12V rail and cabling to go from whatever is designed to the analog board. The first idea is to do something similar to the Artmix design and use an industrial PSU with custom cabling off that. This would be my preferred option really since it cuts $30-$40 off buying a Flex ATX PSU. The specs on the unit I'm looking at are 5V 12A, 12V 5A, -12V 1A. That would effectively double the output capacity of an original Sony Mac SE PSU while only being $35 for a PSU. I'd still need to crimp some stuff together for the actual harness and a fan connection, but it'd undercut the Artmix design by a lot. We're talking ~$60 in parts, however it would not be fansay inside a Mac SE PSU box. That'd be on you to supply. The other to do this would be to base it on a Seasonic or FSP Flex ATX PSU with a custom harness built. All three of those companies make power supplies with a male header on the power supply rather than built in cables. More or less the easiest way to do it would be invest in some minifit connectors and just remake a new harness, something that goes from the PSU's proprietary connector to the 10 pin Molex of the Mac SE power supply connection. I don't think there'd be much of an issue with needing to isolate a 12V rail for the sweep circuit, however if there is it isn't hard to hack a small inline PCB in that would just apply some extra filtering to the lines going to the sweep connection. Using these you don't have to worry about dealing with excess cable like you would with an adapter that plugs into a normal ATX end.
  3. Compgeke

    Modern PSU for the SE/30

    Just curious, does anyone know just how much current is being drawn on the -12V rail of the Mac SE (or SE/30)? The original PSU is rated 0.5A which is not a lot, whereas something like a picoatx is 0.1A generally. I can probably measure this on my own using a Mac SE but I don't have an SE/30 at all.
  4. Nope, it's an actual PCB with an inverter for the /pfw line included on the board. A bit prettier than cable splicing and soft power will still be retained, rather than being hard on or off. You can buy the Molex connectors Apple used in a solderable package meaning assembly isn't too difficult. Even included a fan header so you can retain the cooling system needed, however how to mount that is a later problem (3D printed bracket or something that slides into the original mounting spot I guess). Combine with a PicoATX PSU and it'd be a reasonably pretty internal setup, providing you aren't running a bunch of nubus cards or a pile of big hard drives. The original PSU was designed for 5V 12A whereas your average picoatx will be closer to 8A. The only real "catch" is the -12V line is pathetic on most ATX PSUs, pico included, but to the best of my knowledge it's not used by much of anything except some nubus cards. It's only 1A on the factory PSUs anyway. I don't have a screenshot of the test board that's being produced right now, but here's an earlier screenshot. With any luck it'll fit the IIsi but some rearranging may be required with regards to overhang on the end. Some sort of support will also need to be figured out but that's easier once we have an assembled board with the connector to know what clearance is going to be under it,
  5. Personally I'd buy probably 50 10v 47uf, and 10 16v 10uf caps. They're common values found in just about every Mac of the era and they all need work. In the past I've used: https://www.mouser.com/ProductDetail/581-TAJC476K016SNJ and https://www.mouser.com/ProductDetail/F931C106MAA The other thing you're going to need to recap is the power supply, I don't know of any in person that've outlasted the motherboard at this point. That one you'll need to crack open for values though. Unlike the motherboard there're multiple revisions of even the "Astec" that have different parts inside.
  6. Compgeke

    IIci PSU shrink-tube optional?

    You'll be able to get by fine without rewrapping 'em in heatshrink. I've never done it myself and never had issues, taking note from pretty much every PSU manufacturer out there who also didn't wrap 'em in heatshrink.
  7. Compgeke


    Old school setup for hooking ti a projector generally. To the best of my knowledge there aren't any monitors that'll sync - more or less just late 80s/early 90s projectors (the suitcase sized ones).
  8. Compgeke

    PowerMac G5 Power Cord

    Something worth noting is some later ones require a 20A cord and as such have 3 horizontal pins rather than 3 vertical pins. It's still a standard connector but somewhat less common for a home user.
  9. Compgeke

    Macintosh SE flicker and interference

    Don't trust it. Capacitors are cheap and can fail short and/or go pop when they fail, spewing corrosive goo all over the board. In general capacitors tend to work a little better once warmed up a bit which is probably why it's seemingly working now. Let it sit a few days and it'll be back to before.
  10. Compgeke

    Homebrew PRAM Batteries

    While not quit replacing the Rayovac bricks, these're "in the spirit" so to say. I've been playing with replacing the 1/2AA batteries with CR2032s in systems as a means of cutting costs. I can get a holder for ~$0.75 and a battery for $~0.40 in bulk, a lot cheaper than a $3-$5 battery. Even if they die faster, still cheaper than a 1/2AA. They also tend to be more resistant to leaking, but that's not to say they can't. They do tend to be less destructive if they do. First one I did was a Mac IIsi. It's a bit hacky since I used a reclaimed battery holder made for through hole and it doesn't quite line up. From what I hear it hasn't died yet though - I didn't keep this machine. Next system I tried it on was the Mac IIfx. 7 months later, it's still going fine, power on included. I did use some new holders though, Keystone surface mount ones. They more or less line up perfectly with the original pads, meaning you can tack them down with a little glue then solder like a surface mount device. Some other systems I've done this two are a Macintosh IIci (power on circuit needs repairs, no idea if it's still working) and a PowerComputing Power 100. The Power 100 is still going fine, and it is one of the systems that needs a battery to turn on. Eventually I need to break out the Radius 81/110 and try it out too, I don't have any real batteries for it. I like to keep the real batteries in the special systems like the Daystar Genesis MP - boards I'd like to avoid doing rework on.
  11. Compgeke

    Soph's mac finds

    PCP24xk is the PrecisionColor Pro 24xk with QuickColor. I didn't get a full run of it on the IIfx though, for some reason it'd get part way through and Type 1 error on me. Doesn't do it with any of the other video cards. It's the one card that showed the greatest improvement in PowerPC vs 68k. The one surprising outlier was a dear old Mac Toby that benchmarks almost identical to the Radius PrecisionColor Pro 24xk. I need to make a thread for this some day.
  12. Compgeke

    Soph's mac finds

  13. Compgeke

    Soph's mac finds

    So I spent today benchmarking a bunch of video cards in my IIfx and a PowerComputing Power 100. Unfortunately that Radius card would be much better suited to a PowerPC mac than a 68k mac, but it's a fair bit worse than HPV in the 8100. Under Macbench 4, my PrecisionColor Pro 24xk gets a score of 157 in Publishing Graphics in the PowerComputing but only 48 in the IIfx. An 8100 with HPV will net you a score of 169. I need to get a Quadra to test some stuff in some day to see how much that improves over the 40 MHz '030. If it were me, I'd save it in case I run across a 7100 as an upgrade over the onboard graphics, or something like the Radius 81/110 or PowerComputing Power 100 I've got.
  14. Compgeke

    Mac IIci capacitor damage

    Did you clean the board, and I mean really clean the board after recapping? Cap goo gets under chips and causes weird issues until really cleaned.
  15. For the SCSI 2 SD config did you set the vendor and model to the one in the SCSI2SD in a 68k Mac thread, including the spaces before/after? That’s required for the stock drive setup to recognize the scsi2sd. A really easy way to get the drive setup off the iMac is to use sheep shaver with local disk access enabled so you can copy to/from the computer. Make a 1.44 MB disk image, uncompressed, in disk utility, copy the drive setup, unmourned image, copy image to the local computer, write with favorite utility. If I remember I’ll try and upload one to the thread tonight to make it easier. Another thing to check on your Iicis is the caps and batteries. Both are known to leak on these systems whether they’re in use or not.