Subject: Re: Floppy init
To: None <port-vax@NetBSD.ORG>
From: John Wilson <>
List: port-vax
Date: 06/21/1999 13:00:19
>Date: Mon, 21 Jun 1999 12:37:04 -0400 (EDT)

>If your using a RQDX2 or RQDX3 there is a PDP-11 formatter for RX50
>so the controller an do it.  Also the VAX diags (MDM) had an RX50
>formatter. So if someone can write it the controller can do it.

At least the PDP-11 flavor of this utility (ZRQC??, right?) will only do
RX33s, are you saying there's a way to convince the hardware to do RX50s too?
In my MSCP reverse-engineering adventures I found that the RQDX3's "OP.SP8"
command (WHY doesn't it use OP.FMT like the RQZX1?) is always issued (from the
various PDP-11 utilities that support formating RX33s) with the P.FMTI field
set to 2**31.  I don't remember if I ever got around to trying this but I was
thinking maybe it's actually supposed to be some kind of format menu bitmap,
in which case maybe 2**30 would do the next lower density or something?
Hey it's worth a shot.

N.B. another piece of RQZX1/RQDX3 annoyance is that the RQZX1 apparently
expects the disk to be "online" (with MD.IMF) before formating, while the
RQDX3 expects it to be "available".  Hey whatever.  It seems that these are
the only two device combinations that allow formating the easy way (i.e. with
a single opcode, instead of downloading T11 code into the controller), so
the PDP-11 utils refuse to try either OP.SP8 (name comes from RSX macros)
or OP.FMT except on those devices.  Luckily they don't seem to mind if the
so-called "RX33" is 96 MB long and takes 10 minutes to format, so I've had
no trouble formating Zips on an emulated PDP-11 as long as the controller
and drive types are set to report the right device types.

John Wilson
D Bit