14 May
2009
14 May
'09
5:51 p.m.
I thought it could only format "known" disk
types, not arbitrary disks
(a firmware limitation in the formatter application, not a hardware
limitation).
Surely, it's possible to hack an RQDX3 controller's ROM to support arbitrary
geometries? I have an old ST506 MFM drive hanging around here I keep toying with using.
Does someone have a listing for the ROM?
-cheers from Julz @p
16 May
16 May
11:05 a.m.
On 14/05/2009 22:51, Julian Skidmore wrote:
The geometry information isn't in the controller ROM, it's in the
formatter software. In the PDP-11 version, it's in tables in the
ZRQC??.BIN diagnostics program that runs under XXDP. The tables have
space for eight entries. I don't know about the version in microVaxen,
which may be in firmware. The data isn't just drive geometry, though.
There's lots of other formatting information in the tables, some of
which is hard to work out, things like the encoded drive type,
interleave factors, head-to-head skew, cylinder-to-cylinder skew, gap
sizes, step times, replacement and cacheing control tables, location of
spare tracks and blocks, location of disgnostics blocks, track and block
groupings, that are written to the disk. Something like 40 words per
table, IIRC. I worked most out 18 years ago for some Rodime disks but I
can't find all the notes I made.
--
Pete Peter Turnbull
Network Manager
University of York
I thought it could only format "known"
disk types, not arbitrary disks
(a firmware limitation in the formatter application, not a hardware
limitation).
Surely, it's possible to hack an RQDX3 controller's ROM to support arbitrary
geometries? I have an old ST506 MFM drive hanging around here I keep toying with using.
Does someone have a listing for the ROM? 
12:31 p.m.
On Thu, May 14, 2009 at 5:51 PM, Julian Skidmore
<julianskidmore at yahoo.com> wrote:
The geometries aren't in the RQDXn ROMs - the formatter application
writes them to the disk during the formatter process.
There are three VAX formatters I know of - the ROMs on a VS/uV2000,
the Customer Runnable Diagnostics (CRD) and the Field Service
diagnostics.
I know the CRD formatter only allows you to select known drives from a
menu table and the Field Service formatter allows you to enter
arbitrary values (i.e., has a menu plus a fill-in page). The
ROM-based formatter on the VS/uV2000 was the one I appear to have
mis-remembered the capabilities of.
No hacking of the RQDX3 is required, just selection of the right
formatter application.
-ethan
I thought it
could only format "known" disk types, not arbitrary disks
(a firmware limitation in the formatter application, not a hardware
limitation).
Surely, it's possible to hack an RQDX3 controller's ROM to support arbitrary
geometries?
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ethan.dicks＠gmail.com -
julianskidmore＠yahoo.com -
pete＠dunnington.plus.com