29 Oct
1999
29 Oct
'99
1:18 p.m.
I've found someone who has the entire collection of
disks from USUS,
the UCSD Pascal User Group, and he's cheerfully coaxed his Linux
box's disk parameters into reading the 800K 5 1/4 Pinnacle Systems
disks he had. I hope to decipher the .SVOL "disk volume in a file"
method they were stored in, and post them to my web page soon.
Cool. I *highly* recommend that someone, somewhere, store the raw
disk images for future use. If someone wants to "pull files" out of
the images, that's fine, but the exact image should be kept as the
"master reference".
He also mentioned he has source code on 8 inch disks
from an
Ohio Scientific, Inc. machine. He thought hed have more trouble
finding a way to read those because of its scheme of using an
6820 parallel port controller and a 6850 serial port controller
to access floppies. Is that true?
Yep. Serial data (I think async, with start and stop bits) goes
through a modulator and onto disk. Reverse the process to recover
data.
Should the normal scheme for
connecting a Shugart-y drive to an old AT-era WD controller
work to read these old disks?
Nope, the format is *nothing* like IBM3740, which is all a standard
PC-clone FDC will do. (Admittedly, there are a lot of variants of
IBM3740 that a 765-type FDC *will* do.)
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
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