> I just got a TRS-80 Model 12!! I just got a TRS-80 Model 12!! nyah nyah!!
> It's un-opened!!! It's un-opened!!! WHOO HOO!!!!
>
>
>Dilemma:
> Should I open it and smellthe sweet scent of the ancient '80's air trapped
>in it's plastic bags or let it be, and keep it's un-opened pristine
>state???
>
Just having the original packaging is remarkable.
As for me and my collection, we say keep it intact and untouched for as long
as you can.
----------------------------------------------------------------------------
-------------------------------
Kevin Stumpf * Unusual systems * www.unusual.on.ca
+1.519.744.2900 * EST/EDT GMT - 5
Collector - Commercial Mainframes & Minicomputers from
the 50s, 60s, & 70s and control panels and consoles.
Author & Publisher - A Guide to Collecting Computers &
Computer Collectibles * ISBN 0-9684244-0-6
.
I would like to run 5 1/4 floppies on an older
laptop. Can anyone recommend a laptop
that had this size drive? Or which older
laptops had ports for 5 1/4 external floppie drives?
sring(a)uslink.net
<>>>> Joe <rigdonj(a)intellistar.net> 09/13 9:19 PM >>>
<>>How long can you use the disks before they fail?
<>
<>Only 3-4 times.
<
< Yow! Definitely something wrong there!
Everytime I see that it's a glob of hardend media glued to the head.
Allison
On Mon, 13 Sep 1999, Tony wrote:
> I picked up an HP3421 (I think that's the number -- the data
> logger/multimeter thingy) with HPIL and HPIB on it for a couple of pounds
> at a factory sale aa few years back. Nobody else knew what it was. I
> didn't really know what it was, but it said HP, and looked interesting
> :-)... Still not figured out how to make it do something useful, but it
> returns a sane ID when probed on the HPIL so I guess it's doing something.
That was a great find, especially at that price. I have a couple
of these with the optional HPIB interface.
The most useful card for these beasts is the 10 channel
multiplexer/actuator assembly (HP44462A), usually configured with the first
two channels as actuators . The multiplexer works like this:
when the relay on a given channel is closed, it connects its corresponding
LO and HI lines to the LO/HI lines in the main chassis (which, by the way,
are the same ones available in the front panel). Relays (channels)
configured as actuators connect nothing to the instrument's LO and HI lines;
they just close a switch for external use. Warning: because of this
design, it is possible to tie two channels and the main LO/HI
terminals together by closing two relays at once. The software allows
this (it can be useful in some situations) but it is possible to
inadvertently connect two high-current circuits together, possibly creating
a short. It is also important to remember that when a relay closes,
the corresponding measured voltage is available at the front panel terminals
of the instrument. I like to connect my HP3468A there, since the 3421A
has no display.
The 3421 is really simple to use. Since it has no front panel, it is
always in "remote" mode, and it doesn't respond to the hpil commands
"remote", "local", or "local lockout". It has a set of high level
commands and a set of lower level (or "advanced") commands.
The high level commands allow pretty simple operation, and are mnemonic;
here are some to get you started (note: <argument> is mandatory and
[argument] is optional):
DCV [channel list] Take a sequence of voltage measurements on the
optionally specified channels (up to 30)
ACV [channel list]
TWO [channel list] Two-wire ohm measurements
FWo [channel list] Four-wire ohms; needs special connections and two
multiplexer assemblies.
TEM [channel list] Take a temperature measurement ("T" thermocouple
assumed in the corresponding channel). Each
multiplexer assembly has its own cold junction
compensation.
FRQ [channel list] Frequency reading
CLS <channel> Close an actuator relay or multiplexer channel
(protected; first opens any other closed multiplexer
channels)
OPN <channel> Open " " ...
UC <channel> Unconditionally (no protection) close a channel
When the optional channel list is not specified, the commands
DCV,ACV,TEM,TWO and FWO leave the current state of the relays
undisturbed, so readings are taken from the last channel that was
closed. When the channel list is specified, the last channel that
was closed remains closed. At startup, no channels are closed,
so if no channel list is provided, readings are taken from
whatever is connected to the front panel terminals.
The 3421A can operate for about 8 hours on its internal
sealed lead-acid battery, a Panasonic LCR-306P, 6V, 3.2AH . Unfortunately,
these are no longer produced. I put smaller, 2.4AH batteries in mine,
similar to those used in the HP9114A/B drives. These you can get from
Digikey.
One thing _not_ to do with an HP3421: if you remove a
multiplexer assembly and turn the thing on, it will notice
that it is missing, and the next time you plug it in, it
will label the assembly as "uncalibrated", requiring you to complete
the calibration procedure (all calibration is done in software).
I have not had a lot of time to play with my 3421's recently, but
back in January I built a subwoofer with a three-chamber acoustic
labyrinth. I needed an automated way of evaluating the frequency
response of the thing, since tuning the relative volumes of the
chambers is an iterative process. I hooked a WaveteK 111 voltage
controlled function generator, the voltage control provided by
a DAC08 driven by an HP82165 HPIL-GPIO converter, plus a good mike,
an HP3421A, my trusty HP71B and an HP82164 HPIL-RS232 converter.
So, to take a response reading at a given frequency, first the HP71B
would take 10 frequency readings from the 3421A (connected to the
Wavetek 111), average them, and adjust the voltage control using a
Regula-Falsi algorithm (just a couple iterations required since
the Wavetek 111 is pretty linear) until the desired test frequency
was being output by the function generator. Of course, the subwoofer
was fed by an amplifier connected to the funtion generator.
When the right frequency was being output, amplitude readings were
taken from the mike, and after repeating this for several
frequencies, the response data was downloaded via RS232 to my pc
for further analysis in matlab. After quite a few iterations, I
was able to get the response to where I wanted it. Could not have
done it without the automated rig.
Carlos.
>It's double sided. I'll have a look at the springs as you suggest.
>I think you've answered your own question as to why I assumed bad head
>alignment --- it's what everyone always tells you. (Particularly if the unit
>was shipped without disk protectors installed.) Something of an urban myth
>I suppose.
The shipping cardboard doesn't really protect alignment - it's there to
keep the heads from banging into each other. Indeed, if there is
some physical damage to the heads this could cause it to gouge up the
media too.
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
>This made me remember that I have a perhaps similar problem with one of my
>Kaypro drives. It works at first, but eventually wears away portions of the
>disk making the disk unusable. (After a few uses, if you hold the disk
>up to the light there are arcs
>that are clear.) I assume this is a head alignment issue.
Why assume this? And why is everyone so quick to assume that the
first thing you want to do to a floppy drive is realign the heads?
Reminds me of those folks who insist on tweaking the IF cores in all
their AM/FM radios without the proper test equipment, and then they
wonder why it doesn't perform so well anymore...
In my experience, the only floppy drives I've ever had to realign
the heads on were drives that someone else decided to align the heads on :-).
Two questions:
1. Single sided drive? If so, check the head load pad. An extremely
worn head load pad will gouge up the media for sure.
2. Double sided drive? If so, is there anything wedged in the spring
supports that'll make the heads press against the media with too much
force?
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
>>>> <CLASSICCMP(a)trailing-edge.com> 09/13 5:39 PM >>>
>>This made me remember that I have a perhaps similar problem with one of my
>>Kaypro drives. It works at first, but eventually wears away portions of the
>>disk making the disk unusable. (After a few uses, if you hold the disk
>>up to the light there are arcs
>>that are clear.) I assume this is a head alignment issue.
>
>Why assume this? And why is everyone so quick to assume that the
>first thing you want to do to a floppy drive is realign the heads?
>Reminds me of those folks who insist on tweaking the IF cores in all
>their AM/FM radios without the proper test equipment, and then they
>wonder why it doesn't perform so well anymore...
>
>In my experience, the only floppy drives I've ever had to realign
>the heads on were drives that someone else decided to align the heads on :-).
>
>Two questions:
>
>1. Single sided drive? If so, check the head load pad. An extremely
>worn head load pad will gouge up the media for sure.
>
>2. Double sided drive? If so, is there anything wedged in the spring
>supports that'll make the heads press against the media with too much
>force?
It's double sided. I'll have a look at the springs as you suggest. I think you've answered your own question as to why I assumed bad head alignment --- it's what everyone always tells you. (Particularly if the unit was shipped without disk protectors installed.) Something of an urban myth I suppose.
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
!
!
!
I played with the Osbourne Executive yesterday. I can't get it to boot.
All it says is "boot error". It says the same thing with no disks in it,
MS DOS disks in it and with the door open so the message doesn't tell me
anything. I tried swapping drives, reseating ICs and cables and everything
that I could think of. It booted once and I did DIR on both drives with no
problems, it almost booted several times but filled the screeen with
garbage and locked up. I tried disks from three different sets including a
set of new copies from Don Maslin so I'm sure the the disks aren't the
problem. Any ideas? Does anyone know if DS drives can be used in these?
The drives in it are ALPS SS DD. I took the drives out and checked them,
the heads and drives are clean and the speed is right. I don't think there
is anything wrong with them.
Several people have posted messages here in the past about problems with
Osbournes that wouldn't boot. Did you ever get them working? What have you
found wrong with them?
Joe
My bet would be ls. With Kornshell:
tar cvf /dev/rmt0 $(ls -1F dir1 dir2 dir3 dir4 ... | grep -v "/")
Try:-
tar cvf junkfile $(ls -1F dir1 dir2 dir3 dir4 ... | grep -v "/")
as a test. Otherwise you need to run a shell script with test to sort out
dirs from files.
Neil Morrison
> -----Original Message-----
> From: Roger Merchberger [SMTP:zmerch@30below.com]
> Sent: Monday, September 13, 1999 5:12 PM
> To: Discussion re-collecting of classic computers
> Subject: Really OT: Any tar experts here?
>
> Sorry for the off-topic post, but I'm tired of beating what's left of my
> brains on what's left of my desk... Please, Please, Please, private email
> replies only.
>
> Non-essential info: I'm writing a selective backup program in Perl to read
> a config file, use the info to create a list of directories to be backed
> up, then give that listing to tar to back up the information.
>
> Essential info: Problem is, I have directories that I want backed up, but
> with subdirectories that I *don't* want backed up; yet when I feed the
> list
> of dir's to tar, it recursively backs up the dir's anyway.
>
> Is there a way (program switch, special version of tar, anything...) to
> tell tar to not recurse subdirectories, or do I need to write a
> sub-program
> that extracts each individual filename?
>
> Thanks in advance for any help that can be provided.
>
> Roger "Merch" Merchberger
> --
> Roger "Merch" Merchberger --- sysadmin, Iceberg Computers
> Recycling is good, right??? Ok, so I'll recycle an old .sig.
>
> If at first you don't succeed, nuclear warhead
> disarmament should *not* be your first career choice.
