Interesting reading here under disk formats: https://en.wikipedia.org/wiki/86-DOS
Sounds like there were two Tarbell controllers, single and double density but both single-sided ? Also sounds like the FAT12 disk formats were not quite MS-DOS compatible... m ----- Original Message ----- From: "Richard Cini via cctalk" <cctalk@classiccmp.org> To: <cctalk@classiccmp.org> Sent: Wednesday, August 09, 2017 2:52 PM Subject: Re: Disk imaging with IMD - question > Thanks Chuck. The Gazelle uses the Tarbell DD controller which uses a 1793 > which I believe is 3742 and s/34 compatible. > > Rich > > Sent from Verizon/AOL Mobile Mail > > On Wednesday, August 9, 2017, Chuck Guzis via cctalk <cctalk@classiccmp.org> > wrote: > > On 08/09/2017 10:57 AM, Richard Cini via cctalk wrote: > >> "DON'T ASSUME..." AS THEY SAY ON TV. I'M OK WITH THE ADDITIONAL CLARITY. >> SINCE YOU HAVE A WORKING 242, WOULD YOU MIND CONFIRMING THE JUMPER SETTINGS >> FOR ME? JUST TRYING TO ELIMINATE AS MANY POTENTIAL ERROR POINTS. > > I had a look and a mental fart. I have the 842--the full-height model. > I suspect that the jumpers are completely different. > > If you can use IMD to format both FM and MFM at 500Kbps on your 242--and > "Analyze" reads the format okay, your SCP disks aren't probably standard > IBM 3740 or System/3 type diskettes. They could be in a proprietary > recording format, such as Intel MMFM or Futuredata GCR. > > --Chuck > >
