[Info-vax] SimH with framebuffer and hobbyist kit?

[Stephen Hoffman]

On 2013-04-02 14:26:29 +0000, sean at obanion.us said:

> 
>> 
>>> The VMS V7.3 SPD should say which systems (and configurations) are supported.
>> 
> 
> I have run VAX/VMS 7.3 on my real MVAX 2000, though with 16MB memory 
> (card from Clearpoint...).  This was part of a SCSI enabling project of 
> mine, leveraging reverse engineering by others.  It was slow, did not 
> support TCPIP Services (might support Multinet), but did support LAVC 
> (to a SIMH VAX emulator under OS X) and LAT.  The 7.3 SPD did not list 
> MV2000, but ISTR Hoff saying something like “nothing was changed to 
> prevent it” and I suspect that any prior supported configuration would 
> still be supported.  The Hobbyist version has most if not all of the 
> patches included in the download from last year.

The SPD changes resulted from some measurements that were made and the 
resulting generic increase to the physical memory requirements for the 
OpenVMS VAX software to sixteeen megabytes.

Measurements were (unsurprisingly) showing that low-memory systems had 
poor performance, and the VAXstation 2000 and MicroVAX 2000 were 
constrained to fourteen megabytes.

There were no corresponding changes made to the OpenVMS VAX code used 
by the VAXstation 2000 and MicroVAX 2000, and no boot support was 
removed, nor flagged, nor anything done to prevent bootstraps.    (In 
retrospect, it might have been useful to the system managers to have an 
"unsupported" diagnostic generated and continue booting, but...)

Based on what was being seen back with testing then, the VAXstation 
2000 and MicroVAX 2000 systems will probably still boot and run V7.3, 
but even the maximum-memory configurations will either be constrained 
about what OpenVMS components and particularly application code can be 
run, or it'll be running its memory at disk speeds, or both.   Add 
clustering, DECnet Phase V, DECwindows and a decent-sized application...

-- 
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