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aeberbach

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  • Location
    Melbourne, Australia
  • Interests
    guitar, iOS, making things

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  1. Technically even one extra video card is a second card in a SE/30 - the onboard video simulates a NuBus card in slot E. I don't know if anyone has tried adding two video cards but I don't know why it would not work.
  2. I did make a thing for my own use that requires a Mean Well PT65B supply - it might not be so useful unless you are doing something to replace the original video out, but I'm happy to send STL files if anyone wants to print this thing. It's three parts - mainboard is just within the print capacity of a Prusa MK3S and power supply component is in two parts to avoid the need for supports while printing.
  3. Do you have a crimper? It’s a really important part of the experience, I bought one recently after folding down the tabs with needle nose pliers for years. You don’t have to spend $900 on a real Molex-branded one of course but you must have one!
  4. Interesting - I bet that's for the many CGA or Amiga-style monitors around at the time, if it isn't a proprietary connector for their own monitors. It could be a mirrored display solution - a CPLD with a ROM for configuration, some RAM for a buffer and connection to the PDS slot can easily grab writes to the onboard video memory and output that video in another format. It could also be a 1-bit 640x480 display card. Four memory chips gives it 64k 16-bit words. If the jumpers (JP1, JP2, soldered) follow Asante's scheme that's set for Slot A. If that is a slot identificati
  5. I’m looking at C6, originally 1uF. I see on the schematic it is between pin 7 of UB11 and gnd, labelled SND-R-A/D. Below, UB10 has SND-L-A/D with a 0.1uF cap in the corresponding place. Does anyone have any more detail like a data sheet for these chips? The smallest OS-CON capacitor available is 3.3uF, wondering if it could be used here. I really do like to replace with can style caps if possible - I have a perfect main board to recap and want it to look as original as possible.
  6. I really lucked out with this eBay purchase. It looked good in the pictures but I didn't know it would be this good. And the processor is socketed, so I think I know where the Bolle 50MHz 68030 card is going to live!
  7. @MrFahrenheit Such disparity between values suggests that component is to lower power supply ripple. It was common for “just in case” layouts to be made especially then when a PCB revision was much more expensive and physical space less important than now. If they could buy power supply ‘A’ for $X, then the cost of a 2200uF was warranted. If they could buy power supply ‘B’ for $Y, then the cheaper capacitor was used. (it’s interesting to take a basic power supply, like AC rectified with diodes in a full-wave arrangement and see what happens to ripple using an oscilloscope as a capa
  8. Hey congratulations on that setup, I think I saw that on reddit too. It’s hard to find a machine like that now. I was more an Amiga user back in the day - had a 2500 - it’s nice to imagine what it could have been if someone competent (like Apple even) had that to work with. if I had that I would stay SCSI with a SCSI2SD... perhaps add a FlickerFixer card but not much else.
  9. I may bother the pros with questions, but making this happen with a MAX10 FPGA is also partly a personal learning project. I have no clue about where I might get hold of ASIC equations right now
  10. I would really like to develop a new PDS graphics card for the SE/30. The “Toby’ video card is well documented in the available Apple manuals and seems like a good starting point. (Best way to get a card seems to be buy a whole SE/30 that has a card in it. That’s how I got my Radius anyway.)
  11. Personally I would not be interested though clearly many are. There’s a point at which the thing you have ceases to be a Mac or an Amiga and is just a FPGA or ARM in a retro case, and at that point I think a software emulator is more desirable. Also I’d hate to see the bitter divisions and FUD around the uncertain origins of Vampire and its stewardship come to 68k Macs.
  12. The compact notched keyboard M0487 is a budget board, no mechanical switches, so is a bit mushy. The M0116 might be a good option with ALPS switches just like your AEKII but much narrower. Original equipment on the SE/30 and others; same key layout as M0487).
  13. Ohm’s law tells you current = voltage / resistance, so current = 5 / 180 = about 28mA. Normal for an old LED. Changing R111 to be a 470 or even 680 would probably be a good usable value for a modern power LED, the last thing you want is maximum brightness! You can avoid desoldering anything on the main board by just adding a resistor in series on one leg of the LED. I don’t know how a IIci connects the LED but if by wire that is easiest and you can make it really neat with heat shrink. (There’s a IIci I want but the seller is asking $399. Looks nice but they won’t say anyt
  14. Having a voltage rating that is too high is never bad, it just has to be enough. It’s like using 14 gauge wire for a LED that will see 3V at 10mA. While the measurable resistance of that wire might be very slightly better than a 30 gauge length of wire you won’t really see a change. When I started doing electronics it was not uncommon to salvage huge “computer” electrolytics from power supplies sometimes rated at 450V - I could use those in 9V applications with no problems, in the days before I could afford a stock of more reasonably sized parts. I don’t know what the wobble freque
  15. As long as your physical size is OK, and you don’t substantially worsen parameters like ESR, using capacitors that are well overrated for voltage is not a bad thing at all. Sometimes you might even find they are cheaper if they are a more common part than the lower just-good-enough one.
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