MicroVAX II, VAXstation II & rtVAX 1000

These two simulators are bundled in the same distribution because they are very similar in design. The rtVAX 1000, which is also sometimes known as an Industrial VAX 620 was intended for realtime appications running the VAXELN operating system. It is not possible to run VMS on this system due to differences in the way virtual addressing is implemented. The MicroVAX II can run both VMS and VAXELN (and others).



The TOY clock is used in two different ways depending on whether the guest OS is VMS or not. VMS uses the 2 digit year field only as a way of indicating if the time is valid and also if the time has rolled over into a new year. For the time to be seen as valid, the year must be fixed at 1982. Anything else will cause VMS to prompt for date and time on boot. Other O/S's use this field to actually store the current year. To switch between the modes of operation use one of the following commands:

sim> set wtc time=vms
sim> set wtc time=std

The default format is VMS.

By default the memory self tests (6 & 7) are skipped because they take quite some time to run and serve no real purpose when running on a simulator. However if you want the realistic MicroVAX experience then the tests can be enabled/disabled using one of the following commands:

sim> set cpu diag=min
sim> set cpu diag=full


vax630.exe is the MicroVAX II & VAXstation II, vax620.exe is the rtVAX 1000.

File Type Date
simh-master.zip Source (github) -
vax620_630_v4.zip Executable (Win32) 15/08/2011
vax620_630_v3.zip Executable (Win32) 28/06/2011