IBM channel-attached DASD emulation

Noel Chiappa jnc at
Sat Dec 26 07:36:32 CST 2015

    > From: Guy Sotomayor

    > It's typical of most of the vintage gear. Folks save the CPUs and ditch
    > the peripherals.

It's not entirely sloth and stupidity, though. Disk drives in particular
(usually the biggest issue in this area) are complex precision machinery that
operate at very high speeds, etc, and working on them is a formidable job,
and requires specialized parts which are, in general, no longer available.

    > I think the biggest problem is that there isn't a spec per-se on
    > Massbus. A lot of reverse engineering will be required to make it work
    > properly in all cases.

If it were done, though, that would be wonderful, especially for people with
PDP-11/70's; the UNIBUS on those machines is reputedly the slowest of any
PDP-11, so having mass storage on the MASSBUS is really necessary for good
performance. (Apologies for my -11 centrism in an IBM-focused thread... :-)

But finding the connectors (and probably the cables too) is going to be a
cast-iron nightmare. Maybe we could settle on an alternative (the way I think
we should switch to pairs of dual cards with Berg/DuPont headers, with
standard flat cables between them, to replace the now-unobtainable BC11-A's -
DEC showed this works, with the M9014/M9042..)


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