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  1. glitch

    Ohio Scientific Challenger 4P C4PMF garbage screen

    A couple dead 2114s would make sense, they are a common failure in many things that use them, including OSIs. H/D/M? is the typical boot prompt for disk systems with no ROM BASIC. You press (with caps) D for disk boot, H for hard disk boot (yes, this is a thing!), and M or anything else will...
  2. glitch

    Ohio Scientific Challenger 4P C4PMF garbage screen

    Makes sense, it really looks like it's doing nothing. Dead 6502s certainly aren't unheard of, and with the stock power supplies, a C4P runs hot, which I think makes life a lot harder on especially the RAM. I designed a new universal RAM board, available as a bare board, kit, or assembled+tested...
  3. glitch

    Ohio Scientific Challenger 4P C4PMF garbage screen

    That's great that the lot includes original diskettes! Don't put any in that drive until you're 100% sure the machine is functional: the OSI floppy controller is a very early design that does not use a LSI floppy controller chip, and it's easy to have some problem with the controller frag...
  4. glitch

    Ohio Scientific Challenger 4P C4PMF garbage screen

    The schematic is available, and people did use the Z80 to run CP/M! Seems that the 6800 didn't see a lot of use. The 560Z board does give you true "multiple processors executing code at the same time" multiprocessing. With that board, you can use the 6502 (or whatever CPU is selected, on the...
  5. glitch

    Weird situation with bad sectors on ST-225

    Agreed. I use SpeedStor for LLF and bad block detection/lockout, as well as exercising new-to-me drives or ones that have sat a long time. The SpeedStor seek test is great for getting head positioning mechanisms freed up and going again.
  6. glitch

    Ohio Scientific Challenger 4P C4PMF garbage screen

    Make sure you hit RESET, OSIs usually don't automatically do a reset on powerup! Welcome to the world of OSI! They're interesting machines, and there's a lot of hobbyist interest in them. Check out osiweb.org for more documentation/information. There's also an OSI-specific forum over there...
  7. glitch

    Mid Atlantic FS: Honeywell/Micro Switch Hall Effect Keyboard

    Are these not the same switches rated for a zillion keypresses, like used in the NEC Spinwriter keyboards?
  8. glitch

    Kaypro II "Everything is Broken" Repair

    Carried one on the Amtrak train once, in 2010 IIRC :P People knew what it was! Probably helped it was on the way to HOPE.
  9. glitch

    Mid Atlantic FS: Honeywell/Micro Switch Hall Effect Keyboard

    eBay listing link: https://www.ebay.com/itm/275373808709 Deskthority thread link: https://deskthority.net/viewtopic.php?t=24031 I bought this keyboard a number of years ago with the intention of using it with my Polymorphic Poly-88; however, I found a George Risk keyboard sometime after that...
  10. glitch

    Mid Atlantic FS: 14 Original Random SIG/M 8" floppy diskettes

    link: https://www.ebay.com/itm/275373685432 Already imaged and sent off to The *HUMONGOUS* CP/M Software Archives, though we don't believe these contain anything missing from the current online archives. Figured maybe someone wants these since they're originals and not just user copies, like...
  11. glitch

    Kaypro II "Everything is Broken" Repair

    That's been my experience as well. You see some really complete sets with diskettes and manuals going for $250+ sometimes (actually selling that is), but for an AS-IS "unable to test/smoked a lot when I plugged it in" listing $50-100. I'd imagine a big part of expense going overseas is the...
  12. glitch

    Kaypro II "Everything is Broken" Repair

    Figured someone would get it :P
  13. glitch

    Kaypro II "Everything is Broken" Repair

    Can't save all of them! Thanks! Are they uncommon/expensive on the other side of the pond? They're something that often "just shows up" here.
  14. glitch

    Kaypro II "Everything is Broken" Repair

    Surprisingly well, the outside is in very good condition. There are of course dings and scratches here and there, but I'd have expected paint bubbling/lifting with the amount of corrosion and crust on the fasteners and floppy drives! On the B: drive, it was leaving white streaks on the bottom of...
  15. glitch

    Kaypro II "Everything is Broken" Repair

    Full writeup here: http://www.glitchwrks.com/2022/06/29/kaypro2-repair I bought this Kaypro II as a local pick-up deal in either late spring or summer 2010. It came with a ton of documentation, original diskettes, a Kaypro-branded Diablo printer, and even the faux leather carry cover...
  16. glitch

    Mid Atlantic FS: Microsoft C Compiler 4.00 for MS-DOS Boxed Set

    link: https://www.ebay.com/itm/275368323499 Looks complete, outer sleeve a little beat up. Auction-style listing, starting at $1!
  17. glitch

    Easy IMSAI SIO2 Modification to Allow Use with MITS Disk Controller/FDC+

    writeup here: http://www.glitchwrks.com/2022/06/25/imsai-sio2 Turns out it's fairly easy to disable the command register on the IMSAI SIO2 and allow the SIO2 to coexist with the MITS disk controller (or FDC+). I was able to do it without any cuts or jumps on the actual circuit board, so there...
  18. glitch

    OMS-02 6507 Single Board Computer

    Full writeup here: http://www.glitchwrks.com/2022/06/22/6507-sbc BillO on the 6502 forums traded me a blank board for his then-current OMS-02 6507 SBC back in 2011. He was interested in building one of my 8085 SBCs and I just happened to have a spare board for the 8085 SBC rev 2 on hand, at...
  19. glitch

    Mid Atlantic FS: Microsoft MASM 6.10, Boxed

    I had problems with floppies getting zapped in the mail in the mid/late 90s, mailing shareware disks around. I'm told that the post office doesn't use that kind of scanning equipment before, but still put the stickers on :P
  20. glitch

    GWMON-65 Small Monitor

    I think it's finally ready to be poked at: https://github.com/glitchwrks/gwmon-65 This is a monitor that follows the same command syntax and input/output formatting as GWMON-80, our small monitor for 8080 and compatible systems. It's not really a straight-across port as parts were rewritten to...
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