RX02 drives / RT11
Jerome H. Fine
jhfinedp3k at compsys.to
Sun Sep 24 20:08:06 CDT 2006
>Gary E Kaufman wrote:
> I'm relearning RT-11 on an 11/23 I was kindly given (thanks David!).
Jerome Fine replies:
If you have any other questions about RT-11, please ask. Are you
using V05.0x of RT-11 or V04.00 of RT-11? Both will work well,
but the utilities in V05.0x are a bit improved.
> I'm having trouble with the RX02 drives. I can boot RT11, and .format
I strongly suggest that you make a backup copy of DY0:
COPY/DEVICE DY0: DY1:
DIFF/BIN/DEV DY0: DY1:
> About 1/3rd of the time I get an error while formatting, this is on
> known good 8" SS/DD media that has been extensively tested on a CP/M
> system in both SD and DD modes.
It is possible that DY1: is slightly out of alignment of dirt on the heads.
I suggest that you use the backup copy of the RT-11 boot floppy and
using a blank floppy and ...
> On media which does format fine, I get gobs of bad blocks using
> .initialize/badblocks DY1:
test the floppy on DY0: using
instead of DY1: and see if there is a better result.
> The only media that seems to work fine is "real" RX02 media.
There are no "real" RX02 media - as has been explained by others. The
RX02 media are ONLY an RX01 with the header being set to double
density and the data area then being used at the higher density.
> Is the RX02 incapable of formatting it's own media? Is there a common
> hardware problem that I should look for? Filter caps? Clean the
> stepper motor?
As explained by others, a DEC RX02 floppy drive
is NOT able to perform a RAW LLF (Low Level Format)
of an 8" floppy. That was a decision by DEC to
attempt to force DEC RX02 users to purchase 8" floppy
media from DEC at prices which were many times higher.
All 3rd party RX02 compatible drives which I ever used
(such as DSD or Data System Design) had the ability to
do an LLF of 8" floppy media. Or a Tony Duell suggested,
first do the LLF as an RX01 on a non-DEC system, then
change the media to double-density with the RT-11 command:
on the DEC RX02 floppy drive.
As for other hardware problems, I am only a software person.
My idea of fixing a hardware problem is the swap hardware.
Tony would not approve, but I don't have the hardware
background not the inclination to learn - I am too busy
running a Prime number sieve program looking for Prime
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