18 Apr
2000
18 Apr
'00
12:31 a.m.
My experience with Q-Bus I/O was always spoon-fed via a DRV11-WA card. That
serves to isolate my problems from "theirs." Would it be better done
without the DRV11-WA? It would seem to me that, since the DE timing spec is
typically faster than what the DRV11 requires, yet tolerant of slower and
more varied rates than what the DRV11 can do, it should be quite
straighforward, and probably every bit as fast as anything ANY DEC box with
a Q-Bus can manage. The data I/O comes through a single address, so only
that one address has to be word-wide, not to say it can't be. I do wonder
whether the Q-Bus can generate the appropriate addresses, however, without
hardware help. A bit of steering would, I believe, suffice to make the
interface work from a word-wide bus.
Dick
----- Original Message -----
From: Jerome Fine <jhfine(a)idirect.com>
To: <classiccmp(a)classiccmp.org>
Sent: Monday, April 17, 2000 10:11 PM
Subject: Re: 8-bit IDE
replace
seem
allisonp wrote:
> ALL of the IDE work I've done was with 8085, z80s either stand alone
> (bus less) or S100 Z80s. Further I'm currently working on a Z280 system
> with IDE (Zbus 16bit). This is where I need interfaces and so I can older MFM or
non-existent hard disks. I currently have one S100 system
running a connor3044A (40mb) IDE that will be upgraded to a ST3250
(250mb) as it's a better drive.
The drives I've tried include:
Connor 2022
Connor 3044
WD2120
WD2420
St3096A
St3144A
St3250A
St3660
Fijitsu 528mb
Quantum LPS 80 and 120
Maxtor 124mb
and afew other sub 60mb WD, NEC, Seagate drives.
I now have two 2.5mb IDE in the 700-800mb region I may try one day.
I do have two WD PS/2m30 compatable 8bit IDE 20meg drives.
I think this is a good cross section
Jerome Fine replies:
But have you tried to get an IDE drive to work with a Qbus? That would to be an even better goal? Well at least from my
point of view! I do
admit
to being strictly focused on a PDP-11 as well. I
always wondered why none
of the 3rd party manufactures did not do an MSCP emulation. And if you
are
still concerned about using MSCP until or before the
patent expires, there
are
a number of other possibilities that are much less
difficult and still
allow
a 32 bit block number. Can you at least suggest how
easy or difficult it
might be?
Sincerely yours,
Jerome Fine