18 Mar
2012
18 Mar
'12
8:06 p.m.
shows the 3.5" SS (9121) as being 16 x 256 so I
wonder what the 128 byte sector is, if anything
that I'm seeing
All the ofifical HP docuemtnation that I have (for example the
programming manuals for the 9121, the techref fro the HP150 which used
the HP9121) confirm this. 16 sectors/track, but rather fewer tracks than
uyou might expect (70, IITC, numbered 0-69).
The 9121 was desigend ot be software conmpatible with the older 5.25"
drice units, which had 35 cylidners, 2 heads. Ther was a way to tell hem
apart, but it was not obvious, so machiens that expected the 5.25" drive
could use a 9121 too.
I have no idea waht the extra sector you're seeing is. Does it appear to
contain data (any readable text?). Or is it jsut 0xE5s or 0s' or something?
-tony