DEC Pro operating systems and MFM emulator

Warner Losh imp at bsdimp.com
Sat Jan 23 12:54:41 CST 2021


On Sat, Jan 23, 2021, 11:47 AM Paul Koning via cctalk <cctalk at classiccmp.org>
wrote:

> The question was asked (I misplaced the note) if the OS images that are on
> the Xhomer website work with David Gesswein's MFM emulator on real hardware.
>
> You can turn these into emulator data files, provided you have the latest
> ext2emu tool that's part of David's software (as of 1/19/2021).  The format
> needed is "Elektronika_85" which is the Pro format, called that because it
> was first added to the emulator as the format found on the Russian bootleg
> copy of the Pro of that name.
>
> Results, on my Pro 380:
>
> 1. P/OS 3.2: works.
> 2. Venix: panic at boot, "Bad access number".  That doesn't mean anything
> to me.  I wonder if the issue is that Venix doesn't support the 380.
>

The Venix image is special. Venix doesn't support more than 16 sectors per
track. You may need to put it on a disk whose geometry is 16spt. Maybe that
is why? Venix should support both the 350 and 380.

Warner

3. RT-11 5.3: works.
>
> For grins I tried a smaller interleave factor than the default 5:1, since
> it seems reasonable that this should make things go faster on the Pro 380,
> given that its CPU is about 4x the speed of the one in the Pro 350.
> Somewhat to my surprise this isn't the case; the performance indicates that
> at 4:1 or smaller interleave the software misses the next sector and has to
> wait for another revolution.
>
>         paul
>
>
>


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