25 Jul
2012
25 Jul
'12
6:54 p.m.
On Wednesday (07/25/2012 at 08:19PM +0100), Tony Duell wrote:
I certinly am. The upper board in the drive chassis, the oen that hinges
open. It contains a couple of 2901s and some 2911 sequencers IIRC.
(2) 2901's and (3) 2909...
I've neve seen an official version of it.....
YEars ago, I read out the ROms from an RX02 controller board and
disassmebled the code. I then hand-commented it (well, it was soemthing
to do on the train from Bristol to London :-)). Unfortunately, whilre I can
stil lfidn the hand-commented listing, I cna';t fidn the origianl
machine-readabvle listing anywhere. So I can't easily send it to you.
Are you talking about the board on the drive itself? My old company Writing a disassembler for the mcirocode wasn't
hard once I'd understood
the hardware. Thgen figuring out what the code did wasn't that hard
either, I think it took 3 or 4 train jouneys :-)
I find (4) ROM-like substances on the RX02 controller in front of me.
Three are MMI 7643-5 devices which are 1024x4 bipolar PROMs at locations
E67, E60, E48.
One is a TI TBP24S41 which is also a 1024x4 bipolar PROM at location E53.
RX02 print set here,
http://www.bitsavers.org/pdf/dec/disc/rx02/MP00629_RX02_Sep78.pdf
page 22, shows them all as 7643 type so the TI part is a later substitute
I suppose.
E67 is labled "229F1".
E60 is labled "230F1".
E53 is labled "431F1".
E48 is labled "232F1".
These are not socketed so will need to be desoldered and then fed into a
programmer/reader. It looks like my DataIO System 19 will do 24S41/74S476
so I think I can read them there.
If I desolder these and read them, do we really have use for the bits?
If we'll archive them because there's no archive already anywhere else,
that's good enough reason for me.
Chris
--
Chris Elmquist