IDE on Qbus (was Re: Microvax II)

From: ajp166 <ajp166_at_bellatlantic.net>
Date: Mon Oct 16 19:20:42 2000

From: Ethan Dicks <ethan_dicks_at_yahoo.com>
>Has anyone designed a quick-n-dirty Qbus IDE adapter? If one is willing
>to let the VAX processor do the work, it could be as simple as mapping
>the I/O registers of the IDE drive into some I/O addresses. Not much
>more than a few Qbus drivers and an address comparator, a la older ISA
>IDE cards. It would probably heavily tax most CPUs, though.


Some Russin person did. it's out on the net somewhere.

As to taxing the older CPUs... How? IDE can do real slow, that's
not much of an issue. Most of the VAX cpus do not handle
interrupts very fast due to the huge overhead of context switch.
But they can PIO in a loop fairly fast, that is to the limits
of Qbus.

Allison

Allison
Received on Mon Oct 16 2000 - 19:20:42 BST