From: Fred Cisin <cisin at xenosoft.com>
Subject: Re: place your bets
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Message-ID: <20070303100354.K76450 at shell.lmi.net>
Content-Type: TEXT/PLAIN; charset=US-ASCII
On Sat, 3 Mar 2007, Chris M wrote:
> For fun, how's about we create a list of units that
> had 8" drives. Off the top of my head:
<snippage>
Cromemco CDOS
Cromemco Z2 (Micah)
....
There are a lot more.
..........
------------------------------
AFAIK 8" drives for the Z2 were all third-party; however, the
System 3 and 300 were stock 8" drive systems, first the dual
Persci's and later Tandon TM 848's.
mike
This is on-topic if you think the HP9830 is a computer :-)
I'v been thinking about the internal cassette tape drive of that machine,
with particular refeerence to being able to read/write the tapes in some
other machine. By chance I was looking at the technical manual for the
Racal Thermionic (the company name, it doesn't use valves!) Digideck P72.
This unit has obvious similarites to internal tape drive on the HP9830,
in fact some mechanical parts will interchange between the 2 units.
Anyway, it appears the data format is very similar too.
There are 2 tracks on the tape. A pules on one track is a '0'. A pulse on
the other track is a '1'. And a pules on both tracks together is a marker.
The format of a byte on the taoe is
M b b b b f b b b b M
Where 'M' is a marker (and both markers are part of a given byte, by
default, therefrore, there are 2 markers between the data bits of
adjacent bytes on the tape), 'b' is a bit of the data byte and 'f' is a
flag bit. The flag bit, being in the middle, appears in the same position
in the serial-parallel conversion shift register no matter wheter the
tape is moving forwards or backwards. I think HP used it to identify the
bytes in the fiule header or something.
It's not chear whether HP record 2 markers between each byte, or just
one. But the Digideck can do either.
Anyway, the Racal manual refers to this as 'B.M.S. format'. Has anyone
heard of this? A google search doesn't find anyhting that looks relevant.
-tony
>From time to time I get asked about the Teletype ASR33 Parts List (much
harder to find than the other 2 volumes of the maintenance manual) and
the service documentation for the Facit 4070 paper tape punch (which was
used by just about all computer manuafacturers in the early 1970s...)
I was poking around on www.hpmuseum.net and _both_ are on that site. The
trick is that :
HP2752A == ASR33
and
HP2895A == Facit 4070 with HP modifications (an extra interface PCB, etc)
In the fromer case the 3 volumes of the Teletype docs are available to
download separately (the HP manual just gives the modifications to make
it HP-compatible, and the schematics), tin the latter case there is one
manual, most of which is the Facit service docs and parts lists.
-tony
> Al Kossow wrote:
> > > I have see some disk drives on your homepage and want to ask you if
> > > sale the magnetic and coils from the old diskdrives?
> >
> > no
>
> Hear hear!!
>
> Peace... Sridhar
>
-- html links to eBay auctions clipped.
"magnetic and coils from the old diskdrives" aren't what you'll find
in commodity discs today. I assume he's asking about linear motors
>from large drives, circa '85 and earlier, which have mostly gone into
landfills.
A linear motor from an early 80's drive is on the order of 4" x 8" with
a pretty massive casting.
>
>Subject: Re: place your bets
> From: Fred Cisin <cisin at xenosoft.com>
> Date: Sat, 03 Mar 2007 14:08:57 -0800 (PST)
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>Are there ANY 30 year old computer companies that didn't?
>(not counting "consumer electronics" companies :)
>
Apple! While there were add on 8" drives Apple started with 5.25.
I'm sure there are others.
Allison
A local Art museum here in the Houston area is putting on a Geek Art showing
in August and connected me for ideas and possible help. Is there anyone on
the list living in this area that may have some computer generated art or
any art that would be willing to loan out for the show? Contact me off list
if you like to help out. Any suggests from the list on what you would like
to see in a geek art show let me know also.
Thanks for your time,
John Keys
Apologies for being off-topic. Please reply to me directly, and not the
list.
I've got an ATI Rage 128 GL 16MB PCI video card from a B&W Mac G3. I
put it in my Dell Precision 530 workstation, CentOS 4.4 Linux recognizes
it, but no video comes out. Not even when I tell the BIOS to use that
instead of the AGP card.
Looks like I need to change the firmware from the Mac version to PC.
Searching on Google so far hasn't turned up anything. Anybody know where
to look? Or does anyone have a comparable video card for trade/gift?
--
--- Dave Woyciesjes
--- ICQ# 905818
--- AIM - woyciesjes
"...Talking to you is like clapping with one hand."
Anthrax, "Caught in a mosh"
With that work done, it may be practical to boot your HP over a serial port
at a reasonable
speed, but loading a large ABS file this way can take a very long time (as
things are).
I generally don't recommend the serial boot method due to its poor
performance.
Then again, I think its nothing to throw together a PIC and some I2C eeprom
and build
little paper tape reader and punch emulators, and I can burn copies of any
loader rom
you wish.
I found that serial booting the system to be the easiest way to get started. I don't recall which one but, one of the loader ROMS will work with the "high speed serial" card and read data off a serial link. There's no handshaking or error correction but, with a short RS232 link, passing data is not a problem. The ABS data format does provide checksum error detection so data errors will be detected.
On many occasions, I have loaded HPBASIC and other programs over a serial link with absolutely no problem. The advantage to the serial link is that the only hardware required is a RS232 serial cable. Admittedly, it is not as fast as a parallel link but, who cares ;-)
I had to write a PERL script to format the data before passing it to the 1000 but, that was fairly trivial.
SeeYa, SteveRob
Hi all, this is probably the shortest time I've owned a machine. Bought
just a few months ago as a "project" I now have it to offer again. I
simply don't have the skill to get this running. I've also got too many
other projects :)
It's ex Salford Uni Prime 2550. Comes with 2 disk drives, 1 tape drive,
3 boxes of manuals, 2 boxes of tapes, 4 5.25" floppy drives and a bunch
of terminal lines.
Pictures (including all the manual covers) are here
http://www.flickr.com/photos/17208732 at N00/
Located in Southampton near M27 J7. It's yours for the taking. I'd like
it to go to a genuine collector but will consider any and all interest!
I can hang on to it for a few weeks but it's just taking up valuable
space right now. If there's no interest in the entire system then I may
part out boards, manuals, etc.
As I understand it when I bought this it had sat for a year unused.
Previous to that it had sat for a few years in a garage and been used
occasionally and prior to that had been in the hands of the chap who
rescued it from Salford. When I received it I had problems getting
anything sensible on the terminal then things went downhill and I
discovered the main 5V PSU had failed.
I tried replacing that with an external 200A unit borrowed from my Cray
EL but hadn't considered how many other signals are generated by the
power supply. (MAN070 is available on bitsavers but this only covers
the older Prime models - the power supply signals look the same but the
VCP is very different). The ? 12 and +16 are all OK. I tried faking some
of the power good signals and checked others (50Hz clock, etc). I even
found one signal had broken on the backplane and have repaired that.
Unfortunately without the manual for this specific model I'm stuck. In
it's current condition it just sits with all front panel lights on and
nothing on the console.
CPU:
As I say, the 5V supply has failed. I've patched several lines (the
power good signals) inside the supply. I've had all the boards out,
cleaned the connectors and vacumed the boards and case. I can include an
80A 5V supply if it's of any use to you (I'd hope 80A is sufficient. The
200A unit I was using is now back with the Cray!!)
Disk drives:
I found that the bolts holding the disk units in the casings were
missing (a bag of "spares" was supplied which included the bolts and
rubber mountings). I replaced the bolts before powering up, thankfully!
One of the disk units powers up and spins. The other doesn't power at
all. I removed all the dust too whilst the drives were out.
Tape drive:
Powers up and front panel buttons seem to "do stuff" but can't test any
further.
Tapes:
These are all externally clean but a lot of the casings have cracked.
You'll need some experience with 9 tracks to read these I expect.
Documentation:
There's a lot of very tidy manuals and also quite a few loose manuals in
ring binders. There's also about 10 pocket guides. What is nice is the
collection of history - there's administrator logs, service requests, etc.
Floppy drives:
I'm told the two original Prime badged units have failed. There's a
couple of more modern replacements (and a handful of floppies) included
- one of these should work!
Without a working system I obviously can't test anything. Therefore, you
should consider this as a source of spares or possible repair if you
have the skill and/or manuals. I'm around most weekends for collection
and can obviously give a hand loading. A standard SWB Transit does the
job nicely.
So come on, give the Prime a new home. Please :)
James
After a recent fight with some Cipher tape drives,
trying to boot a system, I managed to badly mangle the
leader of my boot tape. Now, rewriting the tape isn't
a problem, but fixing the tape is. I can cut off the
mangled leader, but then there won't be enough tape
left before the BOT marker. The BOT on a nine track is
just a hunk of sensing foil, just like I remember from
trying to repair eight track tapes (BTW, tinfoil and
double sided tape _doesn't_ work on eight tracks). Rat
Shack no longer sells sensing foil, surprise, surprise
- so, does anyone know of a currently available
solution? That metal duct work tape perhaps? I don't
want to use anything that might risk damage to the
heads though. Any ideas?
-Ian
