29 Aug
2006
29 Aug
'06
5:40 p.m.
Subject: Re: Imaging DEC uVAX MFM drives
From: "Chuck Guzis" <cclist at sydex.com>
Date: Tue, 29 Aug 2006 14:04:30 -0700
To: cctalk at classiccmp.org
On 8/29/2006 at 1:47 PM Zane H. Healy wrote:
>I suspect, but this is only a guess, that the issue is the way the DEC MFM
>drives are formated. There are only two ways that I'm aware of to format
>an MFM drive for use on a VAX. One is with a MicroVAX/VAXstation 2000
>(formatter is built into the ROM's), the other is with the Field Service
>Diagnostics (customer diagnostics can't format drives).
Many ways to format media on DEC systems. One is a suitable controller and
(rqdx2/3)on a PDP-11 qbus machine runnig XXDP diags.
The uVAX2000 has formatter in rom (RQDX3 compatable).
uVAX-II with diagnostic/formatter disks (Rx50) and the RQDXn of choice.
The later uVAX-III I think also had more diagnostic capability.
Bingo. Even back in the old PC XT/AT MFM days, you
couldn't always take an
MFM drive formatted on one manufacturer's controller and use it as-is on
another's.
Generally you had WDxxxx (compatable), WD RLL mostly compatable, and
"other" mostly all over the map but may be compatable with WD1003 style.
The S100 market and controllers were a similar problem. Since controllers
were TTL/CPU and PALS usually the formats were not alike but formatting
was usually not a problem.
SCSI is far easier to live with even older near sasi format (Amprolb).
Allison