9 May
2009
9 May
'09
8:07 a.m.
Steven Hirsch wrote:
Back to the original subject:
I have IMD chugging away merrily on the Compaticard and, thanks to
some advice from Dave, can use it as the secondary controller.
Now, I'm trying to figure out how to format a SSDD diskette for the
Xerox. They use a screwy format where track 0 is FM 128 bytes/sector
(26 x 128) and all the others are MFM 256 bytes/sector (26 x 256).
Is there a way I can kludge through this with IMD? Or, do the Xerox
system utilities actually reformat track 0 when you sysgen (in which
case, it really doesn't matter what track 0 is configured as)?
Steve
Then try to figure it out, Steve. You're doing yourself a disservice by
throwing in the towel so easily on every little question.
Richard wrote:
<<Of the 100 or so Xerox floppies I've archived so far, track 0 varies
enough that my guess is it doesn't matter. I've seen a lot of 26x128 as
you mention, but every once in awhile it is 26x256, and sometimes the
interleave matches the rest of the tracks and sometimes it doesn't. When
the disk is DSDD, track 0 side 1 always matches the rest of the tracks
at 26x256, even if side 0 is 26x128. When I use IMDV to look at track 0,
sometimes it's completely blank and sometimes not. Richard >>
These are not surprising observations: not all disks are bootable. Not
all those disks were necessarily formatted on the Xerox.. some might
have be pre-initialized. 26x128 on T0S0 is your format for booting.
Format -- not sysgen -- formats. Sysgen -- not format -- puts boot
code on that track.