Floppy drive Jumper question

From: Aaron Christopher Finney <af-list_at_lafleur.wfi-inc.com>
Date: Thu Mar 25 12:33:18 1999

On Thu, 25 Mar 1999, Fred Cisin (XenoSoft) wrote:

> > Does anyone happen to have, in some vast catacombs of old manuals/docs,
> > the jumper info for a Panasonic JU-475-2GRJ 5 1/4" floppy drive? Or maybe
> > you can shed some light on what the following sections/jumpers might do?
> > . . .
> > I'm trying to get this drive working with my ATR8000 (recently resurrected
> > from the dead) and am not having much luck formatting disks with it. Any
> > help would be much appreciated.
>
> The Panasonic (AKA Matsushita (AKA Shugart)) #475 is a "1.2M" drive.
> The ATR8000 formats that I have seen were "720K" (in this case actualy
> about 800K), also once known as "QUAD density", NOT "high density". It'll
> be a LOT easier if you can find a 5.25" 720K drive. In the case of the
> Shugart/Matsushita/Panasonic, that would be the #465. (and #455 is the
> 360K model)
>
> If you don't have a choice, then you will need to either jumper or modify
> the drive for 300 RPM operation (default on 1.2M is 360RPM), and jumper
> or modify the write current for low density operation (aka 360K mode),
> while still permitting the 96TPI track density. Typically 1.2M drives
> change the track density along with the recording density.
> SOME revisions of the #475 could be set right, some required some
> minor board modifications.


Thanks Fred, and Pete for the jumper info...

Yes, I've been informed that the maximum drive size on the ATR 8000 is
720K. The CP/M disks I have are for a 40-track, double-sided 5 1/4"
floppy drive. Unfortunately, my floppy drive supply is a bit low, and all
I have are a few Shugart DS/DD 360K drives and this Panasonic.

Thanks to the jumper info Pete sent along, I got the floppy configured OK
for 360K operation, and can format and read disks on it (although it is
the same as the two Shugart drives I had attached...). This drive *is* a
little different than Pete's; I have the holes/markings for some of the
jumpers he mentioned, but no posts, so I may be SOL on doing it the easy
way. And finding a 720K drive at auction for a couple of bucks is probably
the easiest way of all...

I've got a couple of 720K 3 1/2" drives on the way from Haggle, but I
really wanted to get a couple of 720K 5 1/4" floppies on there as well.

Question: Is one media supported more than the other when it comes to
reading/writing Atari format disks with a PC? I know that MyUtil does
something weird with the second side of a floppy (or is it on the Atari
side - something about it writing backwards?), but it'd sure make things
simpler if I could read/write at least 180K disks on the PC (without
using Prosystem)...
Received on Thu Mar 25 1999 - 12:33:18 GMT