DEC MicroVAX 3900 (KA655) with OpenVMS VAX | PCjs Machines

DEC MicroVAX 3900 (KA655) with OpenVMS VAX

Log in with SYSTEM / QUOKKA1953

The machine boots itself: the KA655’s self-tests first, then OpenVMS, about a minute to the<br>Username: prompt. Click the terminal before typing.

The machine below is a DEC MicroVAX 3900 , the Q22-bus VAX built around the KA655 CPU module:<br>a CVAX 78034 at 3.125 MHz with the CFPA floating-point accelerator, the CMCTL memory controller, the<br>CQBIC Qbus interface, and the KA655 console/diagnostic ROM at physical 0x20040000.

Attached devices:

RQDX3 MSCP Disk Controller, with an OpenVMS VAX V5.5 system disk<br>auto-mounted on DUA0:

The console serial line on OPA0:, as a glass TTY — DCL and the boot stream render correctly, but<br>screen programs (EDT, EVE, NOTES) do not paint

The disk image is fetched read-only; writes go to an in-memory copy-on-write overlay that vanishes<br>when you close the tab. Set autoBoot="false" on the element of<br>machine.xml if you would rather stop at the KA655’s >>> prompt and boot by hand.

[PCjs Machine "vax3900"]

Waiting for machine "vax3900" to load....

The port, the media it loads, and how to run it locally are described on the<br>DEC VAX page.

[GitHub Source]