[Simh] SCSI-Interface for simh-vax?

[Jordi Guillaumes i Pons]

Mark,

I’ve got two QBUS interface cards installed in my VAX 4000-200 and uVAX 3300 systems. I think I’ve got no docs though. Would that be of any help (ie, testing stuff on real hardware)?

Jordi Guillaumes Pons


El 1 set 2018, a les 20:36, Mark Pizzolato <Mark at infocomm.com> va escriure:

> On Saturday, September 1, 2018 at 10:45 AM, Eberhard Heuser wrote:
>> Are there any plans to add a SCSI-Interface to the VAX-code?
>> 
>> I want to add the CD-R burning capability but there is no interface
>> (SCSI or IDE) that allows to communicate on the diagnose level
>> with an CD-drive.
>> 
>> I have seen that one can access a physical CD-drive but only through
>> the pudriver and not via the pkdriver.
> 
> Well, none of the current VAX simulators had a native SCSI interface 
> which was interfaced with the pkdriver.  Without a simulated system
> there is no place for SCSI support.
> 
> Meanwhile, 99%+ of the host systems are natively capable of burning
> CD/DVD.  I am not aware of any DEC supplied software running on 
> VAX/VMS which was capable of producing a CD image in the ISO 9660 
> file system format.  All CDs that I ever encountered on DEC systems 
> (produced by DEC for use on VMS systems) had ODS2 file systems on 
> the CD media.  All of the existing VAX simulators can easily produce an
> ODS2 disk image of arbitrary size which can then be readily written on 
> the host system to CD or DVD media with host supplied tools.
> 
> Even if a simulator comes along which does have a built in SCSI support,
> arbitrarily extending that support to interface with CD/DVD media for 
> burning activities would be a challenge to achieve in a portable way 
> to work on most host platforms and as such probably won't get done
> unless you're interested in taking on the project.
> 
> After thinking a little more, I vaguely recall that there was indeed a 
> Qbus board which had a SCSI chip that used the PKDRIVER.  This
> was called the KZQSA.  I tested one once and was fundamentally
> unimpressed by its performance primarily due to it not being a
> DMA device.  In any case, I haven't seen any detailed documentation
> on this board which would be necessary to write a simulator of it, 
> but if you can find documentation, feel free to take a crack at
> simulating it, and delving into the host platform complexities (in 
> a portable way) to burn CD media.
> 
> - Mark
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