15 Dec
2009
15 Dec
'09
4:05 p.m.
Tony Duell ????????:
I've wondered about that too. I wanted to use a G/HPIB ISA card with a
cheap PC to emulate the then more pricey 9134 and I was told that it
was not possible to make a 9914 based ISA card talk Amigo as a device.
But considering that they're used in Xebec controllers that doesn't
seem right. What changed in the Amigo/SS/CS-80/IEEE specs that made it
impossible? I vaguely remember something mentioned about a problem
with how MSDOS talked to discs: by reading/writing sector by sector
instead of files and some associated timing problems. I don't know if
that's correct though, since the Xebec controllers--both the 1-disc
and the 2-disc talks fine to the HP-150. The only problem with it is
that it cannot format a 10Mb disc; it insists on formatting it as a
single 5Mb. Reads & writes it fine, though.
(I'd like to find out how to format discs on a PC for use in the 9134
drives. I could probably use bigger discs if they could be formatted
properly.)
This was from memory. Unfortunately, the 91xx discs are buried deep,
not quickly accessible. I was pretty sure it was a 9914 for some
reason. Perhaps I was thinking of the older floppy drives. Somehow I
forgot to take pix of the HP controllers and only had pix of the Xebec
controllers. Which I can't find now.
--
jd
The Xebec OEM
controller for the 9134A uses a 9914. It speaks Amigo.
IIRC, the later HP board used for the 9133A also uses a 9914. The 9121
Interesting...
I wonder why HP went away from the 9914 in the drive units (all later
drives seem to use either the 8291 or the Medusa) while keeping it in
the host computers.
also uses a
9914.
Every 9121 I;ve seen has an 8291 in it. I have the 'service manual' for
the 3.5" floppy drive units, and while the only schematics it contains
are for PSUs it does contain full parts lists for the controller board in
the 9121. It states it uses a 8291.