VERAULT
Veteran Member
Does anyone know what size and format the Twiggy 5.25" apple drives were? Ya know since they were the ONLY 5.25" floppy drive made by apple with 2 heads...
They used a bizarre format with 46 tracks (using a non-standard TPI of 62.5, vs the 48 or 96 of 40/80 track 5.25" disk drives) with between 15 and 22 sectors per track, for a total of about 870K. The media had a similar magnetic coercivity to 1.2MB high-density floppy disks, it wasn't the same formula as double density disks.Does anyone know what size and format the Twiggy 5.25" apple drives were? Ya know since they were the ONLY 5.25" floppy drive made by apple with 2 heads...
I thought the 8050 required a processor and a good amount of RAM in the drive; rather the opposite of Apple's minimal drive design.
I have an 8050 Drive as well. Dont they require 100 TPI or 96 TPI Quad Density Disks (Ideally)?
Id let you know but my at&t 6300 has psu issuesI know for certain that the Olivetti M24 did at least use 80-track double-sided double-density drives, and could come with them in a stock configuration. Maybe the American edition, the AT&T PC 6300, used it too.
I have floppies labeled with "96 tpi" and "100 tpi" manufacturer's labels. This always got the better of me, so I asked a customer engineer at Verbatim (when they were still operating out of Santa Clara). His response? Identical media--if preformatted, formatted at the stated track density, but otherwise, nada. Mostly a sales gimmick."Quad Density" disks had the same magnetic properties as "normal" floppy disks, they were just (supposedly) manufactured to a higher quality standard because the narrower heads on the QD drives made them a little more prone to errors due to imperfections in the disk surface. Whether there was ever really any difference in practice is certainly a valid question.
Just curious if anyone actually used these and in what. I can’t say I ever saw commercial software on this format.
Commodore did produce several Quad Density drives (what you are describing) and they held 1MB. SFD-1001 is one example, and I believe the 8250 is another.All I could find on this subject is below
DSDD vs DSHD vs DSQD - Vintage Computer Forum
For discussions related to the hobby of collecting, restoring and generally having fun with Vintage Computerswww.vcfed.org
But I am curious what were 5 1/4” 720k DSQD disk drives used in and what years ?
We’re these just a Commodore thing?
When I was very young one of my friends had a 5 1/4” 720kb internal disk drive which was apparently worth mentioning in the 80’s though I remember nothing else about the machine
I do vaguely remember 720kb 5 1/4” disks at a local computer store but never thought much about it.
Was this a thing you bought if you had an old floppy controller that only supported 720kb to max out your 5150?
Just curious if anyone actually used these and in what. I can’t say I ever saw commercial software on this format.
Thanks