> On Sep 13, 2025, at 4:15 PM, Paul Koning via cctalk <[email protected]> > wrote: > > > >> On Sep 13, 2025, at 12:35 PM, Milo Velimirović via cctalk >> <[email protected]> wrote: >> >> >> >>> On Sep 13, 2025, at 10:49 AM, Bill Gunshannon via cctalk >>> <[email protected]> wrote: >>> On 9/11/2025 4:30 PM, Jim Davis via cctalk wrote: >>>> You can get an emulated 11/23 running 4.2 BSD for $3.00. That's crazy. >>> >>> Can you tell me where? With that glaring error I am really >>> interested in learning more. Google finds nothing with those >>> terms. >>> >>> bill >> >> It has to be hyperbole. >> >> No pdp11 ran 4.x, the best you can do is 2.11— which is still being patched >> and maintained; see the pidp-11 mailing list. Probably not $3.00, but $30.00 >> will get you a sytem on a DIP package that will emulate most anything. Spend >> a bit more for a Pi4 or Pi5 if you want to drive a PiDP-11. > > I would think a Raspberry Pico, which goes for $4, is enough of a processor > to run SIMH. Not a large config I suppose, and given that it's a bare metal > system the port would be a bit of work. But it seems doable. > > paul >
SIMH seems to be a bit heavyweight for a Pico, especially in the memory department. I’ve been working on a standalone emulator for a while. An RP2040 is capable of running an 18-bit system with around 64KW of memory while an RP2350 is capable of running a full 18-bit system with 124KW. Using a “Maker Pi Pico” board from cytron.io <http://cytron.io/> (an additional $10) to provide an SPI-based microSD drive, I’ve been able to fun RSX-11M V4.5 and RSX-11D V6.2. Performance is not great but for ~$15, I can’t complain. John.
