18 Apr
2007
18 Apr
'07
1:45 p.m.
On 4/18/07, Barry Watzman <Watzman at neo.rr.com> wrote:
The H-11 was offered from 1977 (when Heath entered the
computer business)
until about 1981 or 1982 ... Although I didn't introduce the H-11 and by the
time I took over was only trying to sell off our inventory, I felt guilty
for offering the system, because I knew that almost everyone who bought it
was making a several thousand (1970's) dollar mistake.
My boss of 10 years ago would be one of the customers who was _not_
making a mistake... he was a PDP-11 consultant who started his own
business (that went under in 1988 when our primary customer decided
to not pay 30K in outstanding invoices and hire our engineers out
from under us, but that's a different story). He
bought an H-11
(and hacked it up enough to use an RLV11) rather than go to DEC
for a "real" PDP-11. I don't have the numbers in front of me, but
he did save a few thousand dollars by going with the H-11.
I think most of your former H-11 customers were probably thinking
the same thing - buy a full-on PDP-11 from DEC for several
thousand, or buy an H-11 for a smaller number of thousand, then
add whatever DEC cards were needed to get to the desired
configuration.
By the time I started working at that company in 1986 or 1987,
I had already amassed a bunch of PDP-8 gear because it was
"so last week". To do some contract work for this
aforementioned company, about five years or so after Heath
stopped selling the H-11, I picked up a used PDP-11/23 in a
BA-11 chassis w/CD slots (BA-11N?) so I could run an
RLV11 myself, and migrate data/programs to and from the
client site. The BA-11N w/KDF11 (11/23 CPU), 64KB of
MSV11-DD (M8044) memory, DLV11J (quad serial), RXV11
(RX01 8" floppy controller), an LPV11 (line printer interface
for an LA180 I already had), and a BDV-11
bootstrap/terminator card was $300. The RLV11 was another
$100 from Newman Computer Exchange or another company
just like them. The 5MB RL01 drive came over from my
PDP-8/a, the RL02 was on loan from my boss... so for $400,
I was in business. A far cry from the thousands he spent on
his H-11 a few years earlier, but my rig would *not* have
been cheap in 1981. It was a good, solid RT-11 system that
I still have set up in about the same configuration (just a bit
more memory now, on a manually-upgraded 22-bit backplane).
That H-11 coincidentally happens to be the most recently used
DEC system in my collection. I'm still trying to get that H27
drive working. I should check bitsavers for schematics for the
Qbus floppy card. The card itself works to a point - if I install
it in a minimal system (CPU, serial, RAM, boot/terminator),
I can get the system to read in the boot sector from the floppy,
but it hangs about the time RT-11 is running far enough to
turn the interrupts on. I suppose I should also track down an
H-11 configuration guide or module list or installation docs or
whatever it came with to ensure I have a happy set of cards
set to happy values. I've checked each chip on the H-27
interface, so I'm reasonably certain it's not a simple hardware
problem; I'm not so convinced it isn't a jumper or other
configuration problem.
Mine came to me with only the enclosure and backplane being
native Heathkit. The rest was 100% DEC (the floppy was never
attached while I worked at that company). If anyone has any
H-11 "getting started" docs, I'd appreciate a copy.
Thanks,
-ethan