24 Jan
2019
24 Jan
'19
8:38 a.m.
On 01/24/2019 10:38 AM, Ethan Dicks wrote:
On Wed, Jan 23, 2019 at 8:41 PM Allison Parent via
cctalk
<cctalk at classiccmp.org> wrote:
The H27 is media
compatible with RX01 but the boot and driver for it is
unique.
RT11 then likely V4 with heath driver and was supplied as a special version
On Jan 23, 2019, at 8:43 PM, Paul Koning via
cctalk <cctalk at classiccmp.org> wrote:
I have an H11 and it has a real DEC
CPU board. The backplane is
Heath, with industry-standard (not DEC's zig-zag) backplane edge
connectors, and Heath parallel and serial cards, but the CPU card is
100% DEC.
On Jan 23, 2019, at 5:37 PM, Noel Chiappa via
cctalk <cctalk at classiccmp.org> wrote:
http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/PDP-11_Models.html
A variant of the LSI-11 is the H-11 sold by Heathkit. Is that actually the same
board? Either way it would be worth mentioning The heath h11 and the lsi11 are
The same right down to the handle. The prime difference
Is the heath backplane is smaller number of slots and user assembled along with the case
and power supply. The memory, io, and disk system
was all heath and could be used in dec backplanes and DEC cards in heath. The heath disk
was RX01 comparable and could format media.
Right. The H-27 disk system definitely
worked with RX01 media and
could format blank media. I have an H-27 that came with my H-11 but
the former owner (my boss at the time) never used the H-27 and I never
got it working to boot from it. My boss did a massive case mod to
extend the width of the box several inches and made a simple 2-slot
CD-interconnect (two Heath backplane connectors and some wire) so he
could fit in an RLV11. That's how I used it at work, and when the
company closed and he gave me the old box, I undid the mod (it was
functional but not strong and definitely not pretty) and so now I
can't use the RLV11 in there any more (yes I have an RLV12 now). The
point here being, we didn't use the H-27 and I never got it working to
boot from it. All I ever had for this box was real DEC RT-11 (v5.4).
I never got the original HT-11 disks, so if the H-27 needs a special
RT-11 driver, that's likely where I'm getting stuck. from heath (HT11). UCSD pascal with a H27 driver was
also available.? Also
TinyC interpreter as a language for HT11.? Back then that was
about it for
the H11.
Common H27 issue was the hub clamp plastic would get brittle and die.
That clamp is likely extinct.
Its the one item I do not have is the H27.? I have ram, single serial
cards (DL copies),
and a parallel card that was used with the punch reader.? Most people
found the
H11 power supply rather flaky and usually moved to a BA11 as both upgrade
and mechanical improvement.? Most that had the H11 moved to more mainstream
DEC hardware and OS.
All my systems use RX11, RX21, or RQDX2/3 with M7555 breakout board
for floppies and MFM disks (RD52 Quantum), one has tu58,? and one system
has RLV21, RQDX3, RX21-RX02, RLV21-RL02.
Allison