35-track drives for the Atari?

[+Larry]

I'm looking at the parameters for a couple of uncommon drives for the A8. These are 35-tracks and 77-track drives.

 

I recall the 77-tracks as being used with 8" disks. For a time (mid-80's?), Top Dos did not support 80-track, 3.5" drives, so I formatted my 3.5" disks with the parameters for an 8".

 

That was 77 tracks, 18 sectors/track, 128/256 BPS, single or double-sided. That would be a maximum of (apx) 700 KB, so I didn't lose too much from the normal 3.5" config. The ATR 8000 could handle these non-standard drives and possibly the Percom drive controller.

 

I also seem to remember that some CPM drive and maybe Radio Shack used 35-track drives, so presumably these could be used with the ATR 8000 as well.

 

Does anyone have any more info, especially on the 35-track versions?

 

Thanks,

Larry

[Rybags]

I'm not sure there were 35 track mechs as such.

 

e.g. the C= 1541 drive only utilizes 35 tracks which was by choice as the drive mechs weren't reliable with their format on the higher tracks, although it's entirely possible to access the remaining tracks.

[tschak909]

Only the earliest Shugart SA400's were 35 tracks. Even the disks at the time were 35 tracks (had a smaller window) By 1978, everything in the 5 1/4" form factor had switched to 40 tracks.

 

An example:

 

http://upload.wikimedia.org/wikipedia/commons/d/dd/Verbatim_5.25_minidisk_tracks_1978.jpg

 

p.s. note the original name of Verbatim Corp. (Information Terminals Corp)

 

-Thom