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Ultimate PDP-8 ideas thread


Veteran Member
Apr 30, 2003
Katy, Tx
We all have our favorite editors and least favorite. I enjoyed using TECO on the pdp-10. Quite versatile. For a quick edit I still prefer VI over Emacs.


Veteran Member
Nov 10, 2009
Please don't shoot the messenger, I was just mentioning another alternative to Vi.
Definitely not shooting anyone here; I was referencing this: https://github.com/emacs-evil/evil

I'm sure I'd get used to TECO and emacs if I forced myself to learn them, but in the meantime, I just force myself to use EDIT under OS/8. It's pretty bad, but not awful. I do wish it didn't have such a limited buffer. Maybe I'll write an editor that uses a scratch DECtape as the secondary buffer to get some additional spinning tape action. :)


Veteran Member
Apr 30, 2003
Katy, Tx
I never used to think I would like Emacs. Then I forced myself to learn to use it. Actually developed a major mode to help with searching a document for specific words for work. I don't mind it but on quick edits I still use VI.


Veteran Member
Mar 12, 2004
Chicago, IL and Buchanan, MI
Haven't been in touch for a couple months, but he's fine as far as I know. He built a couple of the IO boards a few years back (for himself and Lyle) but didn't like the layout and wanted to respin it before releasing. A few years later ...

Bob's collection went to Florida and he's getting tired of fires and mud but not sure if he's following as well.


New Member
Sep 17, 2023
I have been discussing many projects with various people lately, and thought it would be a good idea to get these out to everyone to "vote" on them and express interest to help myself and others prioritize. I will also touch on projects already completed by others for added visibility.

Without further ado...

Omnibus projects:
  • Bus analyzer card to easily probe the backplane with a logic analyzer
  • PDP-8/A MMU for 128kW
  • "The Ultimate" block device, featuring single-cycle data break, SD card storage, 4095 blocks per device, zero seek time, etc.
  • CPLD CPU set
  • CPLD EAE set
  • TD8E controller clone
  • TU10 controller clone
  • RL01/02 controller clone
  • Punched card reader controller clone
  • Paper tape punch/reader controller clone
  • VGA graphics board (possibly emulating a storage 'scope, supporting bitmapped and vector graphics)
  • Programmable real time clock
  • Posibus converter plus multi-data break board
  • Multi serial/SPI/422/485/MIDI interface board
  • Massive parallel I/O card
  • Sound card and general DAC/ADC board
  • LAB-8/E boards and peripherals
  • LINC/TC12/VC12 coprocessors
Many people want more Omnibus boards. Roland has already done a great job providing perfect copies, including the TA8E controller and the RX8E controller, the latter of which can be used with Don's RX emulator. We already have fast serial boards thanks to Philipp's Omni-USB serial board and other CPLD-based solutions, too. Bootloader, memory, and even the VC8E are all taken care of thanks to the efforts of many, including Roland, Vince, and originally, Steve Lafferty for the memory.

Posibus projects:
  • Expansion chassis (allowing small, pluggable modules, smaller than an Omnibus board)
  • TTY interface (Vince has nearly completed this one)
  • VC8I (point plot display controller)
  • KV8I (vector display controller)
  • TC08 (intelligent DECtape controller)
  • DW8E (for connecting to many Omnibus peripherals)
  • DM04 (data break multiplexer)
  • DF32/RF08 controllers and emulators
  • Negative to positive logic converter
We don't want to leave out people with Negibus/Posibus machines, so having some Posibus peripherals would be useful. These of course can be used with Omnibus machines with the appropriate Posibus converter board. The VC8I and KV8I options could be cloned as they are for an 8/I backplane, as well reformatting them onto a single board for the Posibus expansion chassis. David has already created a working DF32 emulator, but controllers are hard to find. Probably not as hard as finding a working DF32, though...

Schematic projects:
  • Digitize PDP-12 schematics
  • Digitize FPP-12 schematics
  • Digitize FPP-8/A schematics
Vince has already done an incredible job digitizing numerous schematics, including the complete PDP-8/I print set, among many others. Here's the print set for the 8/I: https://svn.so-much-stuff.com/svn/trunk/Eagle/projects/DEC/PDP8I/pdp8i-decSCH.pdf This obviously has many benefits over the original, including readability, text searchability, and the ability to export a netlist and turn it into a Verilog PDP-8/I. The same could be done for the PDP-12 and others, once their schematics are drawn.

Simulation projects:
  • SimH LINC/LINC-8/PDP-12
  • Verilog PDP-12
  • Verilog PDP-8/E
Vince, yet again, has been working on modifying SimH's PDP-8 simulator to support the related LINC machines. He's made tremendous progress so far, but it's difficult when so much of those computers were dependent on the peripherals, which can be difficult to simulate.

Other projects:
  • FPGA PDP-12 (would be particularly fun given the number of cool peripherals)
  • FPGA PDP-8/I
  • FPGA PDP-8/E
  • PLL board for an RK05 to use 12 sector packs in place of a 16 sector one
  • Cataloging all PDP-8 software using SHA signatures, keeping track of metadata, etc.
  • A proper vi clone text editor
  • A comprehensive, all-in-one device dump and restore utility with additional error reporting, based upon David's dumprest utilities
A lot of fun could be had with FPGA clones of these computers, since they could even connect to real peripherals and such, given the appropriate bus interfacing. A PLL board replacement in an RK05 allows us to use PDP-11 packs as if they were PDP-8 packs, so long as they are reformatted.

I'd love feedback on any and all of these ideas, and I suspect some new threads will grow out of this one to discuss specific projects.
Look into my project on www.vandermark.ch/pdp8/index.php
It has an emulator and a lot of software and documents also.