Re: Extracting files off “unknown” 8 inch disks. Any thoughts…

[Terry Stewart]

>Here's a writeup for those interested:
>http://www.classic-computers.org.nz/blog/2017-04-15-
adventures-with-an-8-inch-disk-drive-part1.htm

One thing in this project puzzled me.   Initially when I was testing the
drive I tried to format it for 77-tracks. I used the command FORMAT B: /u
/T:77 /N:15  .   It wouldn't let me.  MS-DOS said "
"Formatting 1.15M
parameters not supported by the drive"

After trying a few other things (unsuccessfully)  I just tried a straight
FORMAT B: /u
It then formatted it without complaint?

Listening to the head moving, I counted 77 tracks. The last three tracks
the clicking stopped.  I'm assuming the head just wrote over that final
track 3 times.  MS-DOS told me I'd formatted for 1.2MB.

I'm puzzled why I couldn't format the disk using the /t:77 and /n:15
switches.  Did MS-DOS just go by what was in the CMOS.  If that's the case,
why have those switches at all?   Are they just legacy switches for
pre-CMOS machines?

Anyone know the answer to this?

Terry (Tez)

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