[rescue] Amiga 1000 rescue!

[Peter Corlett]

On Tue, Jun 22, 2010 at 08:28:22PM -0700, Ian Finder wrote:
> Just picked up an Amiga 1000 with a bad floppy drive, and no OS media.

Aha, an old platform I'm intimately familiar with.

You're currently in a bad position since that machine expects to boot off an
Amiga-formatted floppy. You might need a Kickstart disk as well if it's an
early A1000, which are like hen's teeth. (But they're not copy-protected so
it's a case of finding an image and writing it to a floppy.)

You may be able to wing it with an old PC floppy drive. The Amiga expects
drives that provide a diskchange signal, but you will probably be able to
find a PC drive in your junkbox that ties the signal in the right way to at
least convince the machine to boot. If you're really lucky, it supports
diskchange as well. Those are also like hen's teeth.

You can adapt a drive to support diskchange if need be: back in 1990, I
attached a microswitch to a drive to tell whether the drive was loaded and
used a bit of 74 series logic to provide the right signal back to the Amiga.
This allowed me to use cheaper 5.25" floppies/floppy drives and yet fool the
Amiga into thinking they were 3.5" and use them normally.

I can probably dig up schematics if you want to go that route.

Once you have a working drive, you still need to get data onto a disk. PC
disk controllers can't write the Amiga format, and you need to have already
booted the Amiga to load the drivers to allow one to read PC-formatted
disks. If you're expecting to be copying lots of data between a PC and
unusual floppy formats such as the Amiga, consider buying a Catweasel board.