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Author Topic: Can a 1581 drive be made to read Amiga floppies?  (Read 3962 times)

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Offline commodorejohn

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Re: Can a 1581 drive be made to read Amiga floppies?
« on: August 18, 2011, 07:07:50 PM »
Both Amiga and 1581 disks are MFM-encoded as opposed to the 1541's GCR encoding, so it might be within the realm of possibility, actually. It's certainly not going to be supported by the drive firmware, but luckily the CBM 8-bitter drives have enough onboard RAM to allow for significant reprogrammability. There's already utilities that finagle it into reading and writing PC floppies, so I don't see why it couldn't be tweaked to support Amiga disks.
Computers: Amiga 1200, DEC VAXStation 4000/60, DEC MicroPDP-11/73
Synthesizers: Roland JX-10/MT-32/D-10, Oberheim Matrix-6, Yamaha DX7/FB-01, Korg MS-20 Mini, Ensoniq Mirage/SQ-80, Sequential Circuits Prophet-600, Hohner String Performer

"\'Legacy code\' often differs from its suggested alternative by actually working and scaling." - Bjarne Stroustrup
 

Offline commodorejohn

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Re: Can a 1581 drive be made to read Amiga floppies?
« Reply #1 on: August 18, 2011, 10:11:54 PM »
Quote from: mongo;655265
It can't support Amiga disks for the same reason a PC floppy controller can't support Amiga disks. The Amiga reads or writes a whole track at a time. There's no gaps between sectors like there are on a PC floppy (or a 1581 one). That's why you can fit 880k on an Amiga floppy and only 720k on a PC one. You cannot write a whole track of data to a disk with the controller in the 1581, even with the Write Track command, even if you had enough RAM.
Ah, gotcha. Interesting...
Computers: Amiga 1200, DEC VAXStation 4000/60, DEC MicroPDP-11/73
Synthesizers: Roland JX-10/MT-32/D-10, Oberheim Matrix-6, Yamaha DX7/FB-01, Korg MS-20 Mini, Ensoniq Mirage/SQ-80, Sequential Circuits Prophet-600, Hohner String Performer

"\'Legacy code\' often differs from its suggested alternative by actually working and scaling." - Bjarne Stroustrup