17 Oct
2007
17 Oct
'07
4:30 p.m.
I've
always known it as an 'R80' drive.
Right... it says "R80" on the front, but in a variety of places
(Ultrix device drivers, perhaps?) it's also called the RB80,
presumably to distinguish it from the RM80 and RA80 (same HDA, for
folks unfamiliar with it, but 3 different host interfaces). From what I remember, the boards are thr same in the
R80 and RM80 (the
difference, as I said being that the latter has an external
Massbus
interface) but different in the RA80.
The R80 has an 8085 in it, with rows of 8355/8755 (ROM/IO chips) IIRC.
There's an interesting diagnostic facility on one of the boards
consisting of a couple of hex switches, 8 LEDs and some momentary
switches. From what I recall, amongst other things you can read any
location in the 8085's memory space...
Yes... I didn't explicitly state it (but implied
it via the device
names DQA0: and DQA1:) that the RL02 did not require a RL11. As far
as we were concerned, it was a feature, since RL02 was our
"sneaker-net" medium of choice, and at the time, an RL11 was on the
order of $600.
If you have the tape drive versions, there's a normal RL-style connector
on the CPU distribution panel, so presumanly you can cable up an external
RL02.
Can you use an RL01, I wonder. No idea why you'd wnat to, but the manuals
don't say one way or the other, so I am curious.
Once the cables were installed, though, it was a nice
package. The
fact that it was an inexpensive (for the time) Unibus VAX, made it a
I find it impressive that you can build _any_ VAX using standard chips
(OK, with some PALs, and the memory ECC gate arrays from an 11/750 (I
think), but the latter are hardly an important part of the CPU) on 3
hex-height DEC boards.
-tony