Hi Chuck, The drive is a Qume Qumetrak 242 so I assume soft sector? I'm open to correction.
On Fri, Sep 8, 2023, 4:15 PM Fred Cisin via cctalk <cctalk@classiccmp.org> wrote: > On Fri, 8 Sep 2023, Anders Nelson via cctalk wrote: > > Hi all, > > I just bought a very clean, DSDD 8" disk drive off eBay and it has a 50p > > connector which I guess is the common Shugart type? I also found a 50p-> > > 34p adaptor PCB design someone documented online. > > very few of the lines need to be rearraanged, so you can just twist a few > wires in a cable. One exception is that if you need the TG43 signal for > writing, then you will need additional circuitry. > > > I haven't delved much into floppy formats (high level or low level) but > I'm > > somewhat familiar with filesystems from FAT12. My ultimate goal is to > > create an open-source USB adaptor that reads/writes the contents of an 8" > > disk but presents itself to an OS as a Mass Storage Device (block > device). > > Is such a thing possible? > > Sure. Ine the very early days of external USB floppies, there existed a > rare few in which the circuitry was a general purpose FDC. All currently > produced ones are locked in to only supporting a couple of PC 3.5" > formats. Look for "mode 3", which is support for the NEC format, which is > compatible with 8" formats, IFF you can modify the hardware to work. > > > I once created a terrible custom format for storing data on a flash chip > > which required no low-level format, but I expect a magnetic disk needs > > headers/trailers to know when a track starts/stops so it can skip around. > > Yes. It is called "IBM format", but that is confusing, since it is > talking about the track structure that IBM designed (3740?), NOT about IBM > PC (which does use that structure) > > > I checked out the KyroFlux website and it seems there are dozens of > formats > > that were used for 8" disks - is there a favorite format among the > > community that allows full use of a 1.2MB 8" disk? > > Not everybody will agree, but, . . . > NEC modified their 3.5" drives to be 360RPM, same as their 5.25" 1.2M > drives, and 8" drives. Thus, they used the same format on all three > sizes! > > http://www.xenosoft.com/fmts.html#8 > > > -- > Grumpy Ol' Fred ci...@xenosoft.com >
