IDE-Qbus/Unibus was:Re: Old IDE hard drives

From: Zane H. Healy <>
Date: Tue Jan 13 21:49:20 2004

> IDE or SCSI are the choices we have with IDE drives being frequently
> available. However there is no clear solution (that I've seen) as to an ATA
> interface to either Qbus or Unibus.
> SCSI, on the other hand as discussion here has shown, presents a more
> practical mass storage system because there are plentiful reasonably priced
> small-sized SCSI drives out there and even drive interface cards to be
> found, albeit the cards are relatively expensive and somewhat hard to find.

I really feel that unless you're a serious hardware hacker, SCSI is the way
to go. While finding a SCSI controller will definitely take time and money,
they can be obtained quite reasonably if you're lucky enough (I've obtained
one for $5, and another for $50). For drives, all you need is a Narrow SCSI
drive, and the odds are you don't need anything bigger than 2Gb (I use
100Mb, 200Mb, and 2Gb) drives on my systems). SCSI drives of that size are
available, basically for free.

> To that end, given that there were two known homebrew IDE/ATA adapters (one
> from Ukraine; other shown at: ), I want
> to know everybody's opinion of these?
> I know sometime late last year there was some discussion of IDE on the DEC
> busses and I think the question was raised as to whether either worked and
> how well. The question did not get completely answered from what I can
> find. In fact, the ATA adapter has not shown any development
> progress since April 2002, so it may be a non-starter.
> What has anybody else done toward getting an IDE/ATA adapter of some sort
> built and stuffed into their Qbus or Unibus machine(s)?

The Ukraine adapter isn't really practical unless you're in the former
Soviet Union, and have access to chips that aren't easially available
elsewhere. The "CHD" controller (who is CHD?) looks promising, but it also
looks like a dead project.

One other idea that has been bounced around for Q-Bus VAXen is to install a
FDDI card in the Q-Bus system, and a second card in another VMS system, and
then boot off of a cluster disk. Theoretically it has the potential to be
faster than any disk available on a Q-Bus system! The problem is getting
the parts to test the theory, as Q-Bus FDDI cards aren't easy to obtain (I'm
looking for one).

Received on Tue Jan 13 2004 - 21:49:20 GMT

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