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Crutch

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  1. Crutch

    SE/30 not booting from hard drive

    Does your SE/30 have a stock ROM? What system version are you running?
  2. Crutch

    SE/30 not booting from hard drive

    It feels very unlikely to me that you are having a hardware problem (bad traces or bad cable) and the SCSI drive would show up and work perfectly if you start from a floppy. It sounds much more likely there is something on your hard drive causing an incompatibility. Have you tried booting with extensions off? Have you tried installing a fresh OS on the HD (try 6.0.8, nice and small and compatible) and booting from that?
  3. Crutch

    This disk is killing my 400k drives!

    Yes. Originally it came on two 400k disks. Later it was shipped on a single 800k disk. I prefer the full-on classic experience complete with grinding 400k disk drives when you reach a new room, naturally ... “Nya nya nya nya nya”. Greatest game ever
  4. Crutch

    MacSCSI by John Bass AT LAST!

    @Dog Cow implies he has the info. https://macgui.com/news/article.php?t=471 He says it was in the Sep 85 Dr. Dobb’s and subsequent issues. Maybe try here? https://archive.org/details/dr_dobbs_journal
  5. Yep here it is, Technical Introduction to the Macintosh Family p. 227: ”Note: On the older 400K disk drives, a buffer in RAM (actually the low-order bytes of words in the sound buffer) is read by the Analog Signal Generator (ASG) to generate a pulse-width modulated signal, like the sound signal, that controls the speed of the disk motor. This speed variation is responsible for the characteristic humming of the disk drive. The Macintosh Operating System uses this speed control to store more sectors of information in the tracks closer to the edge of the disk by running the disk motor at slower speeds. On the BOOK drives, the variable disk speed is automatically controlled by the disk drive hardware.” https://vintageapple.org/macprogramming/pdf/Technical_Instroduction_To_The_Macintosh_Family_1987.pdf
  6. Excellent, there’s the answer. If indeed all it needs is a PWM on one of the pins, a fun and entirely useless project would be to build a little Arduino hack to enable use of a 400k drive with an SE or Mac II ...
  7. Crutch

    Macintosh 512K revival

    Just what I needed - thank you!
  8. Crutch

    Macintosh 512K revival

    Do you have a photo or reference that shows how to adjust the track 0 sensor? The diagrams in Dead Mac Scrolls are for 800k drives only, I think.
  9. Crutch

    Mac Plus or Mac SE?

    Actually .... I just realized I have a spare Plus keyboard. Platinum I think, with some yellowing, but in great shape otherwise. It’s possible the comma key switch needs replacing (might just need the WD40 treatment though), otherwise it works perfectly. $50 to a 68kmla’er. DM if interested. Happy to test it again also.
  10. Crutch

    Mac Plus or Mac SE?

    In my experience the most cost effective way to get a Plus keyboard is to buy a Plus that comes with one, then sell the Plus. example - this person is considering offers. Comes with a nice working external SCSI HD also. https://www.ebay.com/itm/392855518072
  11. Crutch

    Mac Plus or Mac SE?

    A Plus and an SE with the same amount of RAM* should be almost 100% compatible. The SE will be a bit faster due to architecture improvements, and of course has the fan (though I think heat-related failure rates of pre-SE Macs are generally overstated) and internal SCSI if you like that. I don’t have an SE at the moment but would be surprised if it broke any games that work on a Plus (of course, the really old games might not work on a Plus in the first place). * noted because old games that inappropriately assume the screen buffer is in a fixed location can be broken just by adding RAM
  12. Having some 400k drive issues and hoping a resident expert here can help ... A few weeks back I got out a classic old Mac boxed game (Dark Castle, if you’re wondering) and decided to play it from the disk on my 512k. Annoyingly, the disk wouldn’t read, and suddenly neither would any other disk, so I took a look at the disk - the disk medium looked 100% fine. I decided the 400k drive head must be dirty, opened up the 512k and thoroughly cleaned the head with isopropyl alcohol. Still won’t work or recognize any disk at all (attached video shows what it does when I insert any disk on startup), and will fail to initialize anything inserted. Now I make a mistake and decide, somewhat stupidly, that the disk is probably fine and I just had a weird sudden drive failure ... so I try the same disk in an external 400k drive. All the same things happen. Suddenly I’m worried I’ve ruined two of my drives with this bad disk! Again, cleaning the drive doesn’t help. So I open up the Dead Mac Scrolls and google around for help — I see various mentions of a “track zero alignment procedure” (the Dead Mac Scrolls, p. 274, says if you can’t even initialize a disk, it’s not a stepper motor misalignment but possibly a track zero sensor misalignment) but no good photos or specific instructions for a 400k drive (the Dead Mac Scrolls diagrams are for an 800k drive only, I think). But anyway - how would I very suddenly experience track zero sensor misalignment only after using this particular disk? By the way, I did something risky and tried the same disk again in a disused 800k drive I had lying around ... it also failed to read, and AGAIN the next disk I inserted couldn’t be read either ... however, in my 800k drive, running a normal cleaning disk with alcohol through the drive a couple times got everything back to normal and it’s now 100% fine. Again, though, head cleaning didn’t help my 400k drives at all. So - here are my questions: 1. What the heck could possibly be wrong with this disk that it can ruin any 400k drive it touches (but again, looks entirely OK - it’s not like it’s shedding dust or the disk medium is visibly scratched or anything) 2. What’s the proper and official way to clean the head of my 400k drives? Since head cleaning fixed my 800k drive, I’d think that cleaning the 400k drive heads should work, but it doesn’t seem to ... do I need to do anything other than wipe the little white shiny head guy with alcohol? 3. Is there anything else I should try, like this track zero sensor alignment procedure? Is there a clear set of instructions for that somewhere, specific to a 400k drive? Thanks for any help! 43F84BDC-9B40-43A1-BC28-2C2737C5250C.MOV
  13. I see now you said you had a mouse freeze, meaning you can’t move the mouse at all right? Is this happening every time? Often that indicates a hardware-level issue and Macsbug might not work. (In that case, almost nothing will work really ... ). I had similar issues to what you describe with a Turbo040 installed in one of my SE/30s in the past, never could figure it out entirely — seemed to be heat related (after a while the thing would run hot, and issues would occur randomly). But yes to activate Macsbug you should just be able to hit the interrupt switch, assuming one is installed. If Macsbug isn’t installed, that should bring up MicroBug. Either way, if nothing happens, the Mac is past the point of diagnosis and must be reset. If you CAN get Macsbug up, the next question will be to see what chunk of code is running at the time of the crash. “WH PC” may tell you, or if not do a stack crawl with “SC6”. The Macsbug reference linked above describes these commands - I actually think it’s one of the best Apple technical docs of the time, with great examples and even a basic overview of 68k assembly, but it does require patience to learn.
  14. Crutch

    PB145B’s finds

    Which sensor? I have a bad 400k drive despite being lubed and cleaned. I don’t know much about them.
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