Topic: WTB: quad density 5.25" diskettes for 8250

[Michau]

Pretty much as the thread title says... I need something for my 8250LP, and these QD disks are impossible to find... if you have any to spare, I'd be grateful. I was overbid on today's Ebay auction for 4040

[RobertB]

     I just sent an inquiry to Athana.com for you.  I don't expect an answer until Monday, though.  Cross your fingers! 

            Writing from Aberdeen, Scotland,
            Robert Bernardo
            Fresno Commodore User Group
            http://videocam.net.au/fcug
            July 24-25 Commodore Vegas Expo 2010 - http://www.portcommodore.com/commvex

[BigDumbDinosaur]

DSDD disks will work fine.

[Michau]

DSDD disks will work fine.

Is that so? That would be great I bought a bunch of 150 C64 games, so will try to reformat these disks in my drive

[RobertB]

I just sent an inquiry to Athana.com for you.

     Here is the response!

Hello Mr. Bernardo,

Thank you for your inquiry about 5.25"  Quad Density Disks 96 TPI. We have this product available. The price is  $32.50 EA. BX/10 plus shipping.   We accept Visa, MasterCard & American Express. If you have any questions, please let us know. We will be glad to help.

Kind regards,

Connie Fontaine
Athana International, Inc.
24045 Frampton Ave
Harbor City, CA. 90710
e-mail : connie(at)athana.com
Phone: 310-539-7280

----- Original Message -----
From: <rbernardo@iglou.com>
To: <sales@athana.com>
Sent: Sunday, July 11, 2010 4:30 PM
Subject: Quad-density 5.25 disks?

> Hello, there,
>      I'd like to know if you have quad-density 5.25" floppy disks available.
>
>           Thank you for your time,
>           Robert Bernardo

[BigDumbDinosaur]

DSDD disks will work fine.

Is that so? That would be great I bought a bunch of 150 C64 games, so will try to reformat these disks in my drive

Most likely they won't because the 1541 did not use (or require) DS disks.  The SFD writes more tightly spaced tracks and sectors on the disk, which feature demands better disks.  At one time, BASF produced DSDD disks and I used lots of them with my SFD-1001 drives before I retired them and switched to the Lt. Kernal.  I would buy a box of ten and format them all when I first opened the box.  I never had any trouble with them.

Interesting history trivia: the SFD-1001 was originally intended for use with the B128, which as we all know, was such a huge success for Commodore.  When it became clear that the B128 was an overpriced and obsolete door stop, Commodore called in the liquidators, who also took the SFDs.  What was once a pricey floppy drive became a cheap and easy means of adding more storage to the C-64 and C-128.  You could hang up to four of them on one computer (the SFD's controller could only be set to device 8, 9, 10 or 11).

Interesting hardware trivia: the floppy mechanism used in the SFD was made by Panasonic and was mechanically identical to that shipped with IBM PC-AT machines.  Unlike the PC-AT, which spun its disks at 360 RPM and could format them to 1.2 MB, Commodore rigged up the mechanism to spin at only 300 RPM so it could use the less costly DSDD floppy disk.  That, along with the use of GCR instead of MFM recording, produced a 1 MB usable capacity.  The Panasonic mechanism was very rugged and SFDs seldom failed as long as they were kept reasonable cool.

[Michau]

WooHoo, it works! I bought a bunch of DSDD Maxwell diskettes, supposedly some C64 games were on them. I reformatted them and they work! 1MB on a disk which would have only 360kB on a PC - that's really good.

See attachment

[Steve Gray]

WooHoo, it works! I bought a bunch of DSDD Maxwell diskettes, supposedly some C64 games were on them. I reformatted them and they work! 1MB on a disk which would have only 360kB on a PC - that's really good.

See attachment

I compliment you on your choice of computer! Contrary to other opinions expressed here, the CBM-II machines were actually quite advanced and hardly obsolete at the time. Their pricing was inline with the PET/CBM machines they were designed to replace. Lets not forget that they ran at 2MHz, supported upto 1MB ram, had a SID chip, and probably the best keyboard Commodore ever produced on an 8-bit machine. They even allowed an 8088 coprocessor board to run MS-DOS.
 
The 8250LP is a beautiful drive, with amazing capacity at the time. The combination of B128+8250LP makes a sharp looking system (the LCD monitor doesn't hurt either).
 
As for DSDD disks in an 8250... don't try reusing disks that have been previously formatted on a 1541/4040 or PC because they probably won't work due to the 48/96-tpi tracks meshing with the odd 100-tpi format of the 8250. Brand new, unformatted disks is the way to go, or alternatively use a disk bulk eraser (if you can still find one) to wipe out the formatting completely from a previously used disk.
 
If you need/want more info on the CBM-II machines check out my web page:
http://www.6502.org/users/sjgray/computer/cbm2/index.html
 
Steve

[Michau]

Thank you for your compliments The CBM-II architecture looks really intriguing, and at the same time easy to modify electronically. For me, the most interesting 8-bit machine Commodore ever did.

I reformatted some 1541 disks and they appear to work, but I will be cautious. Thanks for the warning.