Amiga A1020 5.25" floppy drive (was Re: Atari modem)

From: Doug Spence <ds_spenc_at_alcor.concordia.ca>
Date: Sun Jun 6 16:16:13 1999

On 19-May-99, Mark wrote:
>Hi,

Hail!

>Talking of the Amiga 1020 drive... I would like to get hold of one of
>these. Am I correct in thinking that they were not sold in the UK
>(where I live)?

I don't know the answer to that. I don't know of that many A1020 owners
in North America, either. :) It was basically only used for reading
MS-DOS format 360K disks with Transformer, but there was also commercial
software that used it to read/write C=1541 disks. I think one of the
RKMs mentions software for reading/writing Apple ][ disks, too, and I'd
like to locate that. (I can only _read_ Apple disks ATM).

>If I can't find an A1020 (or compatible replacement, if any were made),
>I may try and rig up my own drive.

There were third party Amiga-compatible 5.25" drives made. Picking up a
random magazine (Amiga Format, January 1991) and leafing through, I
found an ad for the Cumana CAX1000S on p.165. Not really compatible,
though, as the Cumana drive has a high density mechanism in it. I think
there were others as well, also with high density mechanisms.

The Cumana drive also doesn't seem to have its own power supply. The
A1020 has its own internal supply, instead of drawing off the Amiga's
floppy port.

I've never met a C=1571 in real life, but I think the A1020 uses the
same case as that drive. Just look for a 1571 with a checkmark logo on
it. :)

>To this end, can some kind person who owns an A1020 open it up, and
>tell me what type/model the drive mechanism is, and also describe
>any interface PCB that's inside?

The mech is an ALPS DS/DD, but I don't know the exact model number.
Doesn't matter, because any standard mech will do.

The interface PCB only has three TTL chips and a few capacitors and
maybe a transistor (can't see the third leg). It's probably not _quite_
the same as as the board from a 3.5" drive, because the A1020
isn't recognized and mounted automatically. It has to be MOUNTed
manually, using an appropriate mountlist. (440K Amiga disks! WooHoo!)

It has the passthrough for daisychaining other drives, too.

There's really not much to it. Rigging up the appropriate cabling
between any old 5.25" mechanism and the innards of an A1010 would
probably work.

Note that there is no diskchange signal from the drive. You have to
remember to issue the diskchange command when swapping Amiga-formatted
5.25" disks, to avoid corruption. Not that this is likely to be a great
concern. :)

>-- Mark

-- 
Doug Spence
ds_spenc_at_alcor.concordia.ca
http://alcor.concordia.ca/~ds_spenc/
Received on Sun Jun 06 1999 - 16:16:13 BST

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