Remote job submission from PDP-11

Glen Slick glen.slick at
Wed Oct 7 11:06:41 CDT 2020

On Wed, Oct 7, 2020 at 8:37 AM Ethan Dicks via cctalk
<cctalk at> wrote:
> On Wed, Oct 7, 2020 at 5:07 AM Peter Allan via cctalk
> <cctalk at> wrote:
> > I am looking for the following software products for a PDP-11, ideally to
> > be run on RSX-11M.
> >
> > 2780/3780 Protocol Emulator
> I used to do this with specialty hardware...
> ... and there were "non-intelligent" mostly-software HASP and 3780
> emulators, but I say mostly-software because you still needed a serial
> interface that could do Bisync (BSC) - like the DP(V)11 or DU(V)11.
> ISTR these chewed up a bunch of CPU, even on a VAX, and that's why we
> had a market for a $2,500 card and $20,000 license.
> While I do have all the code (and a fair amount of the hardware) from
> Software Results, writing a COMBOARD emulator would be rather complex
> - the core is a 68000 (easy enough to start from) with a COM5025 or
> Z8530 for a USART (probably not a ready-to-drop-in chunk of code) plus
> a DMA engine to the host bus implemented in two ways (different
> COMBOARD models).  That last bit would require deep understanding of
> the original hardware.
> There were also intelligent sync serial engines for this from other
> vendors, including DEC (KMC11, and probably a later one but the device
> name escapes me).

I was curious about this DEC M8704 DMS11-DA that sold cheap a few days
ago. It has eight SMC COM5025 "Multi-Protocol Universal Synchronous
Receiver/Transmitter USYNR/T" chips:

Apparently it can't do anything on its own. It needs to be connected
to a UNIBUS through a companion KMC11 processor board, which might not
be too common if someone wanted to put together a working

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