26 Aug
2025
26 Aug
'25
9:13 a.m.
On Aug 26, 2025, at 10:51 AM, Martin Eberhard via
cctalk <cctalk(a)classiccmp.org> wrote:
Nice!
How do you load software into it? There's always the toggle switches if you have
enough patience. Or do you just update the ROM?
For that machine, with a full load of memory, you have a bunch of OS options. RT-11/SJ or
/FB, DOS-11, RSTS-11. That last option would be amusing: a machine quite similar to
yours, with the addition of DECtape and another 15 DL11 interfaces, is what my alma mater
used for the college timesharing system in 1973-1974.
paul
Interesting for Tesla’s early history, but skip
to 49:00 for a nice rack
he is putting together with an 11/20.
https://youtu.be/88KHfX_kPIY
He also appears to be on the cctalk list.
:-) Yes, I'm on this list. I was surprised to see Kim Java show that
snippit of my PDP11/20 restoration project. I wasn't even aware that the
camera was rolling at that point!
So far, the CPU and the extended arithmetic element seem to be working
great. I've got my own SRAM board
<https://deramp.com/downloads/mfe_archive/005-Documentation%20and%20Code%20by%20Martin/PDP11%20Stuff%20by%20Martin/Unibus%20Boards/Unibus%20RAM0ROM-Bootstrap/>
in it. The RX211 is also working great, as is the DL11. I'm in the process
of restoring the RK11 disk subsystem (RK03 Diablo drives, external
controller). I can now read, write, and format on one of the drives. The
other has lots of work to be done. I need to tear both drives apart enough
to replace the rotted foam seals for the air-blower interface, and the
rubber strip on the front door. I am also considering cleaning and
re-lubricating the bearings on the positioner assembly. as they feel a
little crunchy. Amazingly, I just bought new air filters for the Diablo
drives!