> I=B4m afraid this computer is off-topic (dated 1988). Sorry.=20
Never mind. There were system/36 machines around in 1985 and even
earlier...
> An IBM 5363-I has recently been given to me, but I don=B4t know anything
> at all about its internal architecture or capabilities. I only own the
> Central Unit; no cables, no floppies, no tapes, no manuals, no
> terminals.
I don't know the system/36 awfully well - I worked more on system/34s -
how big is this physically? The 5362 was desk-side, the 5364 desktop
(the same box as the PC/AT), but I don't know the 5363 (probably after
my time if it's 1988).
> * It has two 15-pin sub-d connectors in one expansion card. They seem to
> be for attaching two serial terminals (syncronous? type 5250?)
Dunno. Probably not 5250 - these hang in chains (pun intended) off the
twinax ports.
> * In another expansion board it has a 9-pin sub-d connector.
> * There are too four twin-axial connectors.
Four? Quite a sizeable system, then.
> Can anybody help me on this subject?
>
> Thanks in advance.
Just my tuppence worth! I'd guess you've got a fairly powerful (by
1980s standards) machine.
Philip.
Hello... some time ago, there was talk of building a computer, and now I
think that I've got a (bad, possibly) idea. In the earlier half of this
century, transistors weren't avaible... vaccum tubes... huge ones, but
now, the transistor has made small ones possible. My point: If we were
to take a tubed design, and re-build it with transistors, we could
probably make it a decent size.
So, what da ya think?
Tim D. Hotze
>Some people (esp. on this list) may not realize it, but there are actually
>hordes of people out there who go their entire lives without ever owning a
>single screwdriver. Which is why I've got two in/on my laptop case,
several
>in my laptop "kit", and a swiss army knife with a flat sd, phillips sd,
>pliers, and (8^) corkscrew.
I treated myself to a Leatherman folding tool 6 months ago. It's got a very
well-made #1/#2 combination phillips, plus a very nice pliers & other stuff,
even a tiny screwdriver (screweler's jewdriver, as my spoonerist father
would have said). $40 at Wal-Mart, and the best tool purchase I've _ever_
made. It hangs on my belt all the time -- even take it to church. I'm always
ready to fix.
Buy one.
manney(a)nwohio.com
Murphy was an optimist!
At 05:13 PM 11/23/97 +0000, you wrote:
>
>
>On Sun, 23 Nov 1997, Charles E. Fox wrote:
Thanks, Tony, I will give it a try.
Charlie
>
>>
>> On a TRS-80 Model I, no expansion unit, I am getting the left half of the
>> screen filled with graphics and the right half with scrambled text. Does
>> anyone have a suggestion of where I should start looking for the solution
>> to this problem?
>
>Well, it's been 5 years since I read the Model 1 technical reference
>manual, but I can still remember some bits of it (I hope)..
>
>Start by opening the case, laying the 2 boards out component-side up, and
>connecting power and video. If you want step-by-step instructions on how
>to do that, please ask. Turn on the machine. Is it fixed? If so, suspect a
>solder-ball short (these were quite common one some batches, I believe) or
>a problem in the keyboard cable, which carries the Z80 bus. In fact,
>checking that keyboard cable for continuity (with the machine off, of
>course) wouldn't be a bad idea.
>
>OK, still not fixed? Check the PSU. The 0V line is the -ve side of the
>largest capacitor on the board, and all the supply rails go to the DRAM
>chips (-5V on pin 1, +12V on pin 8, +5v on pin 9).
>
>Now switch off and pull the shunt block (it looks like an IC, but has
>metal shorting bars on it only). That disables all the DRAMs. Turn on
>again. On a Level1 machine (and I believe a level 2 machine, but my manual
>isn't that clear) you'll get a 32*16 display of colons. If that occurs,
>then you've probably got RAM or RAM addressing problems.
>
>Switch off again, and pull the ROMs (or on a level 2 machine, pull the 24
>pin ribbon cable from the ROM socket). Turn on again. The Z80 data bus is
>pulled high, so the machine executes continual RST38 instructions and
>fills all of the memory with 39 00 (the return address, of course). The
>display will fill with alternate '@' and '9' symbols, in 64*16 mode. If
>that works, then you have ROM trouble, I think.
>
>If you still don't get the right display, reseat the Z80, and then use a
>scope/logic probe/LogicDart to find out (a) what the Z80 is doing, (b)
>what the buses are doing and (c) what the video controller is doing.
>
>
>>
>> Thanks
>> Charlie Fox
>>
>>
>
>-tony
>
>
>
Hello,
I hope this mail goes to the right place as I'm not on the list; here
goes:
I am messing about with an 8088-based clone to see what I can do with it
for cheap thrills & a good learning experience. So far, I have
installed
a V20 chip which decreased processing time by about 7%. I then tried to
clock it at 10 MHz (the rating of the chip), but this failed to produce
any results (the 'puter did not boot.) I tried at 8MHz, and the
computer
booted but did not give a display. I could tell it was working by
entering
DOS commands. I tried then at 5.33 MHz. It booted & ran OK (as far as
I
could tell), but the display was all messed up. I then did some
research
and found that the CGA card depends on the 14.31818 oscilator to run
properly.
Since the processor seemed to be running OK at 8 MHz, what I want to do
is
find a way to send a proper clock signal to the CGA card while clocking
the
main board at 8MHz. Or will changing to a different monitor (like VGA)
make the clock speed irrelevant? Is CGA the only clock-dependant
display
type?
Thanks in advance,
Dave
<instead of the vinyl, would a small section of heat-shrink tubing work? Ni
<it a little longer than the thickness of said ferrule, then hit it with
I presume over the gummy roller. The problem is the ferrule for the tu58
is 0.435 od, the roller is 0.625 od. The gummey material does not hold
shape in the advanced cases of rot. The tygon tubing has a 0.385 ID and
when stretched over the ferrule has a od of 0.610 after grinding. This is
adaquate as the tape speed is servo controlled via read back data.
Having worked with machines used to produce pharmaceuticals I have a
better than average appreciation for various elastic materials. There
are many of them to choose from and the urethanes or neopyene are a good
choices but Tygon(aka Vinyl) thick wall tubing is a easy one to obtain and
use and proven satisfactory. The later ease of availability and use are
key in the selection.
Allison
Allison
<I have told my friend not to toss the drives so I think one or the
<other of us will have some to play with now. Thanks for the tips;
<it's, well, reassuring that someone has already figured something out.
They are repairable.
<The only thing I'm worried about w/r/t hardness is whether that will
<create additional wear or reduced traction with the belt capstan.
The belt capstan is very hard. The tygon after 6months of constnt use has
shown good wear and the same tape has been used with no bad effects nor are
any expected. I could think of a dozen materials I'd like to try but this
was the only one available and its worked remarkably well.
Allison
I have to say I love my new Starlet (PC-8401-A, CP/M laptop) but it seems to
have a problem. When turned off, the memory gets all scrambled. The longer
it's off, the more scrambled it gets, until any saved files are gone and the
directory entries are filled with garbage filenames. Formatting RAM1 clears
it, but it will happen again.
I've tried leaving it plugged in and made sure that there are fresh
batteries in it. Nothing helps. Also, when it's on, the low battery light
comes on or flickers, even if its plugged in.
Thanks in advance...
--------------------------------------------------------------------- O-
Uncle Roger "There is pleasure pure in being mad
roger(a)sinasohn.com that none but madmen know."
Roger Louis Sinasohn & Associates
San Francisco, California http://www.crl.com/~sinasohn/
A relative of mine has a DecMate III. It comes with a cheap word processor. I
have used it, and have found it very difficult, worse than vi or something.
Could someone tell me if there is any use for it? It has no hard drive...
allisonp(a)world.std.com (Allison J Parent) wrote:
> this is also common to DEC TU58 tape system (also a dc100 cart).
Yep, I forgot about those. Sorry about that.
> The solution I've used to date is to first strip the goo off the alumninum
> ferrule that is on the drive. Then I found a peice of tygon(vinal) clear
> tubing that had the required ID for a tight fit. I cut a ring the width of
> the original(cut squarely and clean) and proceded to glue it on using
> superglue (cyanoacrylic). then I run it up on a spare motor and grind it
> using a emery board. The last step it insure roundness. I've done this
> for 6 tu58 drives and it seems to work fine. It's noisier as it's harder
> but seems to have enough friction to drive the tape well.
I have told my friend not to toss the drives so I think one or the
other of us will have some to play with now. Thanks for the tips;
it's, well, reassuring that someone has already figured something out.
The only thing I'm worried about w/r/t hardness is whether that will
create additional wear or reduced traction with the belt capstan.
> The material is not the best possible choice (polyurethane might be better)
> but I had it handy and it's easy to find. Between uses I pull the tape to
> avoid dents that seem to cause no problems other then making the drive
> very noisy. It's been in use for about a year, so the tygon hardening
> from age was a concern. However it works and it's easy enough to do again
> if needed.
Pulling the tape is sound anyway, at least in the bigger QIC drives
that I've dealt with, leaving the tape in sometimes results in the
tape getting dents from having the head pushed into it for so long.
Today I ran into Paul Coad and he mentioned seeing similar stuff
happening to QIC drives, and I think I've seen it too on some HP
9144s. This could be extra nasty on 9144s: they use tapes that look
like QIC but have some subtle differences, like being preformatted
with block markers written with a special full-width head and I
suspect (from experience with a drive that was trashing tapes) that
you can scribble over the block markers if the tape speed isn't right.
Of course, once you do that the tape is mechanically OK but the drive
will not let you load it.
-Frank McConnell
