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  1. mikerofone

    Commodore 8250 disk station making loud buzzing noise

    Awesome, thanks for the detailed instructions Dave! The hot and buzzy regulator is indeed the 323, i.e. the 5V one. The next time I can get tinkering, I'll test it and the others as you described. Good idea to use a "chocolate block" for probing, thanks! I hadn't heard that term before, but I...
  2. mikerofone

    Commodore 8250 disk station making loud buzzing noise

    Allowing myself to bump the thread, in case someone might have an opinion on whether the buzzing sound and heat should be cause for concern. :) Thanks!
  3. mikerofone

    Should Commodore 8250 disk drives be "banging" the drive heads when homing?

    Hi again, starting another thread for a different question about the same device. The drives in my Commodore 8250 disk station don't seem to know when they're at track zero, and I wonder whether that's normal like for the Apple ][ drives, or whether there should be a track 0 sensor that is...
  4. mikerofone

    Commodore 8250 disk station making loud buzzing noise

    Hi all, I got a Commodore 8250 disk station last weekend. It's working mostly fine, but the drives needed some service and I removed the filter cap after it blew up on me. (I looked for Rifas, didn't find any and thought I'd be safe - I was wrong! It stank about 100 times less than a Rifa...
  5. mikerofone

    Profile Hard Drive PSU giving low voltages, any usually suspect caps?

    Yep, I'm familiar with that lovely odor and "looking forward" to that! -_- need to order the replacements first though. "Whoops, forgot to remove that bit in the listing, that was left in from the previous Lisa I sold." Possibly still a lie, but at least the Rifas in the Lisa PSU were replaced...
  6. mikerofone

    Profile Hard Drive PSU giving low voltages, any usually suspect caps?

    Thanks for taking a look and confirming my suspicion! So I'll replace them all and won't take any chances. To clarify, the seller said he replaced caps "where necessary". Apparently, Rifas don't automatically make the cut for him. I checked my message history with him and he thinks that if they...
  7. mikerofone

    Profile Hard Drive PSU giving low voltages, any usually suspect caps?

    Hi all, (TL;DR: My Profile got more and more unreliable in the last two years: It worked fine two years ago, then sat for the better part of a year after which it required multiple power-off/power-on cycles to initialize properly. After an additional 20h of runtime Lisa started crashing more...
  8. mikerofone

    Compaq Portable III - how to get 640KB of base RAM?

    Wow, great job hunting down the culprit! The magic of having more than one device cake to the rescue again. :) Thanks a lot for demystifying my error code in the process! I'll hope that it's a dead RAM chip indeed, instead of the same parity checker chip you found to be bad. I won't be able to...
  9. mikerofone

    Compaq Portable III - how to get 640KB of base RAM?

    Hi silvervest, No worries about the necro. :) I didn't continue the investigation further as I didn't have replacement chips at hand, and instead turned to another machine in my ever-growing incoming project queue... Are you sure that the replacement 128kB you tried were good, i.e. were you...
  10. mikerofone

    Compaq Portable II: low-level format of HDD with MFM-to-IDE adapter

    I have an awl (? this thing) that I pushed against the hole, and then heated up by holding my soldering iron against it. Worked surprisingly well, after just a few seconds it pushed right into the plastic. A bit of wiggling to ensure the hole is wide enough and now the cables fit well. I...
  11. mikerofone

    Compaq Portable II: low-level format of HDD with MFM-to-IDE adapter

    I tried, but they are keyed (one hole plugged), and the headers on my controller aren't. Though, maybe I should just get out them side cutters... if the cables can be keyed, surely the controller end doesn't need those pins either. I just need to triple check that I got the cables the right way...
  12. mikerofone

    Compaq Portable II: low-level format of HDD with MFM-to-IDE adapter

    Sorry for the lack of reply, twolazy. I checked the diagnostic disk and couldn't find a specific formatting tool. I found that the IBM Advanced Diagnostics Disk had a LLF tool (via https://minuszerodegrees.net/ibm_xebec/ibm_xebec_llf_add.htm) but that one failed the same way - the disk kept...
  13. mikerofone

    Compaq Portable II: low-level format of HDD with MFM-to-IDE adapter

    It does. The others aren't populated or documented either. Makes me wonder whether there might be a jumper setting for "initialize drive". As the drive is nonfunctional and I have a second, working one I put into the Compaq, i might as a last ditch effort just try to see what happens when I...
  14. mikerofone

    Compaq Portable II: low-level format of HDD with MFM-to-IDE adapter

    Yup, exactly the same board. It seems that it supports exactly two drive geometries, or at least only two modes are documented in the portable 2 service manual: 20MB (Seagate ST225 compatible I believe) or 10MB, switched by a jumper on the board. This person seems to have been successful with...
  15. mikerofone

    Schematic for Compaq Portable II please ?

    Hi zippysticks and Trapani, just chiming in that I just repaired my Portable II which had the exact same problem. It still turned on but something smelled burnt after 2-3 seconds, and I eventually spotted that the same resistor was quite crispy, but still measured a perfect 22 ohms. The...
  16. mikerofone

    Compaq Portable II: low-level format of HDD with MFM-to-IDE adapter

    Hi all, I got a Compaq Portable II with a Miniscribe 8425 HDD. It's an MFM drive that has an MFM to IDE adapter board bolted to it's underside, labelled WD1001-IWH. The system HDD controller is IDE. The drive seems to be fine mechanically, but seems to be unable to find tracks. Any read to the...
  17. mikerofone

    Imaging a non-standard Apple ][ disk (Wanco 8201 controller) with Kryoflux

    This did the trick! Seems like the only thing I was missing was how the format flags need to be arranged on the command line, as I now was able to get a good reading via the following: $ dtc -finput/track -i0 -m1 -z0 -g0 -n+16 -s0 -e34 -foutput.img -i3 I don't see the neat strings diskblitz...
  18. mikerofone

    Imaging a non-standard Apple ][ disk (Wanco 8201 controller) with Kryoflux

    Hey all, you folks rock, thank you so much! \o/ I have struggled with finding proper documentation for using the Kryoflux correctly, especially for cases where the disk at hand is not of a known format. I always feel like I must be missing an obvious step, as the official documentation goes...
  19. mikerofone

    Imaging a non-standard Apple ][ disk (Wanco 8201 controller) with Kryoflux

    Hi all, I recently acquired a mystery computer from a local auction, which turned out to be some sort of machine controller built from a 16k Apple ][. I've documented this with tons of pictures here: https://photos.app.goo.gl/Hf6aCHKaDx42Xncg7 The floppy drive in there is a Wangco 82 with a...
  20. mikerofone

    PSA: Floppies showing corruption when mounted in Linux = possibly Bootsector virus

    Correct, clamav only reports. My hi-tech way of fixing certainly does NOT involve writing the image to a floppy, fixing it in f-prot on a real machine, and then reimaging it. ...sounds like something I should just set up a dosbox script for, maybe.
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