amiga archaeology.
© 2002 Jamie Zawinski <jwz@jwz.org>


Flushed with my success with getting that Mac doing something interesting, I started messing around with my ancient Amiga 1000 again. This is the machine I traded in the Mac for, back in the day. I still have it, and as of a year ago, it still worked: I was still able to play Lemmings on it, displaying to my big TV. But, the last time I turned it on (about six months ago) the magic smoke escaped. Eeek! Turns out that some component of the SCSI controller in one of the two external 20M (yes, M, not G) hard drives I have had turned to dust. I don't remember what was on that disk, but I'm pretty sure I have floppy backups of everything.

Anyway, that was sad, but I got my Lemmings fix by getting UAE, the Amiga emulator, running on Linux. It works really well! Though I think it really ought to also simulate the distinctive groooonnnnk sound that Amiga floppies made: it just doesn't seem the same without it. It's like the music in the game has been replaced with the ``no-disk-noise remix.''

I've found that to get the Amiga to boot, I sometimes have to smack the top of the floppy drive when it's about halfway through reading the Kickstart disk. This isn't terribly surprising, since it's all tricked out; it's got 2M of RAM on a daughter board that sits on a riser between the CPU and its socket, and there are hand-soldered ground wires going all over the place, because at some point in the '80s I read that the grounding on this board was sketchy and that it would crash less if you soldered together pin N of all of the RAM chips (or something like that.) Plus at some point I had to replace the floppy drive (I bought a box of 20 drives and found 2 that worked) but it didn't quite fit, so I had to take tin snips to the shielding, and jam in a big screw to replace the missing "eject" button. It's quite the little Frankenstein.

So, since my A1000 is apparently disintegrating before my very eyes, I figured now was a good time to get the bits off those floppies and onto a network-connected machine. It's apparently impossible to actually read Amiga disks in PCs, in much the same way that you can't read old Mac floppies. I was hoping that perhaps this meant that old Macs could read Amiga disks, and I could use this ClassicII to do it, but I haven't found any evidence of that being possible either. (Three different incompatible breeds of floppy drive controllers? Who knew.)

So then I went digging through my Giant Box of Cables, in hopes of getting a serial link going between the Amiga and Linux, and transferring files with Kermit or something. I found all kinds of interesting (and sometimes unidentifiable) things, besides the usual tangle of power supply cables, speaker wire, and RCA cables, like:

But the one thing I couldn't find was a null-modem adapter. This was puzzling, as I was pretty sure I'd even used one within the last five years, so I couldn't imagine where it got to. But, it turned out that one of the unlabelled serial cables was rolled, so that worked.

First I tried transferring files using Kermit over the serial port, at 19.2Kbps. That was paaaainfully slow, so I dug up a copy of CrossDos, and tried transferring the files by writing them to PC-formatted disks from the Amiga. That was, I think, even slower, and certainly more work, so I went back to Kermit.

Old versions of Kermit have about 75% transfer overhead, which is huge. There are apparently ways of lowering that overhead by changing the settings in the Kermit programs running on both ends to increase packet size, etc... But the Kermit binary on my Amiga doesn't have those newer options. I tried, repeatedly, to download newer binaries of Kermit to the Amiga, only to find that every single time, the last few bytes of the file were getting left off, and so I couldn't unpack it! I even tried appending a bunch of NULLs to the file before transferring it, but that made the unpackers unhappy too...

It's very strange rescuing all these Amiga files from oblivion: I keep running across things like 8-bit 320x200 photos with my friends from high school mugging for the camera. Very disconcerting. And ``rescuing the files from oblivion'' is really what it is: because I think the only way to keep information from vanishing is to keep it online. Hardware decays, backups decay, hardware to read backups vanishes. But if the file is sitting in your home directory, and you keep automatically copying it around as you upgrade to newer and newer computers, the bits will continue to be readable... Assuming people keep the emulators running.


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