PDP 11 Hacking: GOT IT WORKING!!!

From: Jerome H. Fine <jhfinexgs2_at_compsys.to>
Date: Wed Feb 9 20:17:27 2005

>Vintage Computer Festival wrote:

>>On Wed, 9 Feb 2005, Jerome H. Fine wrote:
>>Other question:
>>(a) Which memory are you using?
>I ended up with a Camintonn MEV-504 which is a 2MB Qbus card.
Jerome Fine replies:

Interesting that the CMV-504 stopped with a different error
than the M8044 board from DEC. If you eventually run
RT11XM mapped monitors, you can use the extra memory,
especially V05.0x from RT-11 which can use all 4 MBytes.
But remember that the RX02 controllers support only 18 bit
addresses (256 Kbytes or 1/4 MByte).

>>(b) Does the DSD drive work as well?
>The DSD drive works on drive 1. I'm about to go open it to see about why
>drive 0 is not spinning.
I saw your reply that the drive belt is the problem.
Usually it is something simple with RX02 drives.
But until you were able to boot on DY1: proving
that the controller and floppy were OK, it was
almost impossible to know. Knowing where to
look is a big help!

How does the DEC RX02 drive work?

DSD also makes a DSD-880/30 which is an emulated
RX03 floppy drive (works great in single sided mode as
well as an RX02) and 3 * RL02 drives which can't
be removed. I have a spare, but no spare controller.
They are heavy to ship!

>>(c) How do you clean the heads on an RX02 drive?
>With a standard 8" drive cleaning kit (I've got several around here
>somewhere) or with a cotton swab and some head cleaner. If you go with
>the latter method, you must open the RX02 enclosure, then remove a screw
>or two that allows you to flip up the controller board, but you must
>remove a bunch of cables and connectors to do so (make sure you note where
>they go; they're all pretty obvious except for the small cables that go
>off to each drive, which are on different positions on their respective
>connectors). The drive heads are then accessible, and you can clean them
>with a bit of your preferred cleanser and a cotton swab. Then
>re-assemble in reverse.
>I did this with Howard Harte's RX02 drive when we were reading disks on
>his system last week and it made a huge difference with certain disks:
>they would return numerous read errors until I cleaned the drive head
>(which had a skidmark on it) and then they read just fine (except for one
>which had a hard error).
I should get one, but I use the RX02 or RX03
so rarely these days.

Sincerely yours,

Jerome Fine
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Received on Wed Feb 09 2005 - 20:17:27 GMT

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