> From CLASSICCMP-owner(a)u.washington.edu Wed Mar 11 12:38:47 1998
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> To: "Discussion re-collecting of classic computers" <classiccmp(a)u.washington.edu>
> Subject: Re: Preserving old floppies, fixed disks...
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> At 11:46 AM 3/11/98 -0500, you wrote:
> >
> >I know I saw a post on this a while back but I don't recall
> >any of the suggestions for preserving old floppies. I have
> >a few things on 8 inch floppies that are pretty much irreplacable
> >so any ideas are welcome!
> >
>
> Other than storing them in a cool, dark place I don't thing there's a whole
> lot you can do to curb the aging effects. We're starting to see problems
> with 9 Track and QIC tapes (5-10 yrs. old or >), not so much with 8"
> diskettes--yet.
The concensus on the "Community Memory" computer-history list, IIRC, was
that to preserve the DATA it was a good idea to periodically migrate it to
newer (types of) media. If you want to continue using the same PHYSICAL
media (type), for purposes of "completeness," sentiment, etc., I assume
you could simply (?) read-and-rewrite the data back onto the "same" media
(whether the "same tape," or just "another tape of the same kind," is up
to YOU). I can however envision situations in which system resource
limitations might make it difficult to do that -- only one drive, no spare
"blank" media, insufficient memory to buffer a copy of ONE tape/disk
while swapping to the next one (more of a problem with tapes than with
disks). You might be able to get around some of these problems with
clever programming (i.e. tracking media position and restoring positions
around multiple medium-swaps!) -- but I'm not about to assume that you guys
can all PROGRAM all the machines you COLLECT. (Can you?)
Me, I'm a DIY-software-head. I don't buy, or even dumpster-dive for,
much hardware that I can't at least POTENTIALLY program...
Chris Chiesa ("the still-pretty-new guy")
I know I saw a post on this a while back but I don't recall
any of the suggestions for preserving old floppies. I have
a few things on 8 inch floppies that are pretty much irreplacable
so any ideas are welcome!
Also, I have a number of machines that I don't use on any sort
of regular basis that have hard drives in them. I don't expect
these things to last forever but is there something I can do to
prolong the life of some relatively unused machines. (An old
Xerox comes to mind) Should I "start 'er up" every so often
(like a car in storage) or is it better to just leave well enough
alone?
Thanks!
Les
lfb107(a)psu.edu
[tony duell]
:> oh, add a sirius one to the list; we forgot it.
:Still sure you don't want to LART me? There's a few about - I was
"lart"?
:given one a few months back. Strange machine - the disk controller
:has a 8048-series microcontroller and a lot of TTL on it. It's an
:8088 machine, but virtually all the I/O chips come from the 65xx
:family, etc.
not surprising, considering that chuck peddle designed the 6502 in the
first place. he was especially keen on the 6522 and tended to scatter
them around his designs like confetti... ;> the disk drives used gcr and
ran at variable speeds, not unlike the mac's (although was the gcr
encoding method a more traditional 4 bits onto 5, as opposed to apple's
software-based 6-to-8?) and also boasted a capacity of 1.2Mb and a data
rate of 500kHz. and an 800x400 screen that took memory from the main
map, rather than its own little partition off somewhere else.
it wasn't a cheap design, but it was what the ibm should have been if it
*had* to use that particular architecture...
:Yes, 'everybody's got an 11' - but it's the sort of machine you
:should have anyway :-). IMHO it's a very clean architecture.
hmm. maybe. *grudge grudge* yes, it is a very nice architecture,
particularly in the way both the source and destination operands can be
specified as being in memory for all instructions (rather than just
loads) - but our objections to actually having one are not based in
rationality in this case...
:And surely it's better to have a real PDP8 than to have a simulator
it depends what you want it for. we want it for the programming
challenge (what can usefully be done within 4k?) and it makes sense for
programming challenge phase 1 to be hacking out a simulator. getting the
real pdp8 is something we'd see as the last step, not the first.
:Well, a Daybreak (the smallest, commonest D-machine, I think)
:turned up at a radio rally a couple of weeks ago. It was the first
:one I'd seen outside a museum....
hmm - so how much did you pay for it then...? :>
[tiger]
:The design was sold to HH electronics,
:who went broke (no idea whether the cost of making the Tiger had
:anything to do with this), and the machine never went into
:production.
probably - ram was expensive, modems were expensive, 7220s were
expensive... it would have been a hacker's dream, but for most
hobbyists, possibly overkill.
-- Communa (together) we remember... we'll see you falling
you know soft spoken changes nothing to sing within her...
Net-Tamer V 1.08X - Test Drive
This morning I went to a trift store and found an IBM PC that said
"Personal Computer 3270". How rare are these? I've never seen one before.
I have seen AT 3270s but not a PC. This one had a full height hard drive
with IBM logo on it and a full height 5 1/4" floppy drive with IBM's logo.
It had model 5271 marked on the back.
Also a few weeks ago I saw an IBM AT that was marked "Personnal Computer
AT Store Controller". What is it for? I've never heard of one. The owner
said that he had already "modified it" to make it a regular computer.
Joe
<> More recently, Intel designed the 8089 I/O co-processor as part
<> of the 8086 family. It had an instruction set optimized for I/O
<> functions.
And not so recently starting with the AT and all after the keyboard
interface chip is a slave cpu (8041a or 8042).
In 81 I started a system using multiple z80s and 8085s to do things
like disk IO and loosely coupled multiprocessing (using z80s). When I
had it up and operational it could outrun a dos powered 386/20.
Slave procesors and distributed cpus are not new. One favorite is the
PDP-12, a PDP-8 with a linc-8 as a peripheral. The PDP-10 used PDP-8
as an IO processor or later ones used PDP-11s. Even the Microvax-II
disk controller had a T-11(chip version of a base PDP-11).
Allison
> Daniel,
>
> Does the system 34 use *" floppy disks? I don't know anything about S34
> but I think I got a bunch of disks this weekend and I think some them are
> original disks for the S 34.
>
> Joe
I don't know about Daniel's machine but every System/34 I've ever seen
does. It takes them either singly or in "magazines" of ten diskettes.
I recommend that anyone with a S/34 tries to get hold of some of the
empty magazines - or even full ones.
AFAIK, IBM's idea was you kept yor software, backups etc. in magazines,
unless it was 3 disks or fewer. I imagine most people did what people
nowadays will be forced to do - keep the disks in conventional boxes and
load the magazines immediately before insertion into the S/34.
Philip
;-) Clearing the snow from my glasses, I saw Russ Blakeman typed:
Nuts... Sorry, guys!
"Merch"
--
Roger Merchberger | If at first you don't succeed,
Owner, MerchWare | nuclear warhead disarmament should
zmerch(a)northernway.net | *not* be your first career choice.
I found an interesting gadget at a hamfest last weekend. It's a Digi-Viewer
made by SwTPc. It's a gold colored metal box about 6 x 5 x 4 inches. It
has the outline of an IC on it and 16 lights around the outline to
represent each IC pin. There's a cable coming out of the box with a 16 pin
chip clip on the other end. It's AC powered and looks like it uses
incandescent bulbs instead of LEDs. I've never heard of one before but it
looks like a prehistoric IC pin status display. Anyone here ever use one of
these?
BTW A friend of mine has a digital clock made my MITS. How rare are they?
Joe
Sure thing. I have one of those beasties. Before I could afford a
good oscilloscope it seemed like a nice way to bench-test some digital
(DTL & TTL) circuits. Modified mine with connector for the cable
attachment to the box so I could plug in different IC clips for different
sized components. Also could use it as a pretty dumb "logic analyzer"
with a cable that had clips or probes on each pin.
It never worked very well for dynamic circuits (not surprising) but I
did get a lot of use from it while breadboarding.
Gary
At 03:18 PM 3/10/98 -0500, you wrote:
>> I found an interesting gadget at a hamfest last weekend. It's a Digi-Viewer
>> made by SwTPc. It's a gold colored metal box about 6 x 5 x 4 inches. It
>> has the outline of an IC on it and 16 lights around the outline to
>> represent each IC pin. There's a cable coming out of the box with a 16 pin
>> chip clip on the other end. It's AC powered and looks like it uses
>> incandescent bulbs instead of LEDs. I've never heard of one before but it
>> looks like a prehistoric IC pin status display. Anyone here ever use one of
>> these?
>
>Yes, I have seen them, but that's about it. SWTPC made quite a few things
>that were not related to thier 680x based micros - in fact some things
>were not digital at all!
>
>William Donzelli
>william(a)ans.net
>
