Picked up 6 Morrow MD computers this past weekend.
All appear to work, however I have one with floppy drive
trouble ...
The drives in question are TEC FB-503 1/2 height 5.25"
drives. Only one of the machines has these drives.
What is odd is that both drives in the one machine will
not read diskettes (report disk error - won't even boot).
Only one machine has these drives - when it failed to boot,
I first tried cleaning it - no improvement - then tried
swapping for 'B' drive - still no improvement - now thinking
that diskette controller is faulty.
Then I swapped in a Panasonic drive from my parts shelf, and
voila - boot & access disk no problem.
Seems really odd that two identical drives would fail so
completely in the same way when all of the other 10 drives
appear to be OK.
I thought that perhaps they were 80 track drives or some such,
however Issue #1 of the "Morrow Owners Review" has an artical
about the floppy drives used in the MD's, and it lists the
TEC/NSA 5503, which looks like these drives - Can't say for
sure if they are the same ones, as the model number stated does
differ slightly from what is on the drive plate, but if they are
the same, the artical makes no mention of anything special about
them...
Does anyone know anything about these drives? Are they 80 track
or otherwise "odd"? Are they known to have a high failure rate
(especially with age)? Any info would be appreciated.
Regards,
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Vintage computing equipment collector.
http://www.parse.com/~ddunfield/museum/index.html
>From: ard(a)p850ug1.demon.co.uk
>
>> > I don't like to test memory.
>> > My tests are all open book - they don't need to write anything on their
>> > shirtsleeves.
>> > open notes - they don't need to write anything in the margins of the
>> > book.
>>
>> Couldn't agree more. In "real life" you normally have access to
>
>I'll go along with this too.
Hi
One of the most important parts of school learning is to
learn how and where to look for information.
Another is to learn how to simplify concepts so that they
can be applied more universally.
Dwight
---snip---
At 21:03 13/04/2004 -0400, you wrote:
>I've been contacted by someone with "5 or 6" Morrow MD-3s, a couple of
>MD-2s, and maybe an MD-11 (she's not sure). Most are working, and they come
>with lots of software. She wants some money for them, but I'm not sure how
>much. Drop me a note if you want me to put you in touch with her. The
>systems are in Toronto.
>
>--Mike
Just a follow-up in case anyone is interested...
I finally made it to Toronto this past weekend and picked up the Morrows.
In total, there were 7 machines, of which one was given to York university.
I received 6 Micro Decision machines of which two are MD-2's, and 4 are MD-3's,
All appear to work!
I also received 5 terminals, 3 Morrow OEM versions of the "Liberty 100", one
Morrow MDT-60 (can't find any other manufactorer name), and a Morrow OEM
ADM-20 by Leir Siegler. I haven't tested all of them yet, but the ADM-209
does work.
The "mistery" machine was not an MD-11, it was another MD-2 with the odd looking
2/3 height SA-200 drives, and paired with the ADM-20 terminal - this is in fact
the exact configuration shown in all of the Morrow advertising materials for the
MD's that I have been able to locate.
There is a fair bit of software, including a CP/M edition of Wordstar for which
the diskette packet has never been opened!
I also have a full compliment of Morrow manuals.
Still have lots to go over - Pics and other material will appear on my site within
the next few weeks. I'd be interested in corresponding with anyone having experience
with Morrows, especially the MD series.
Please see my next posting for a inquiry involving a "floppy drive oddity".
Regards,
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Vintage computing equipment collector.
http://www.parse.com/~ddunfield/museum/index.html
>From: "Dan Veeneman" <dan(a)ekoan.com>
>
>Fred,
>
>Do you really give out tests like this:
>
>At 06:06 PM 6/23/04, you wrote:
>>int N = 10;
>>while (N--) printf("&d\n",N);
>>What are the first and last numbers displayed?
>>is appropriate for open-book.
>
>I'm presuming there's a typo inside the quotes...
>otherwise you have a nice trick question!
>
Hi
Evaluation order can be important in many context.
That is why I like a more concise language than C.
Dwight
>From: ard(a)p850ug1.demon.co.uk
>
>> > I know how, just about every part of, a microwave oven works and
>>
>> Then you'll know why the HV supply is almost invariably voltage
>> doubled AC and not rectified and smothed DC.
>
>I know it is (the magnetron itself is one of the diodes in the doubler,
>along with one capacitor and a semiconductor diode), but I don't actually
>know _why_. Presumably it's to simplify the insulation of the transformer
>or something.
>
>-tony
>
Oops
I missed this question. Tony is right. Also, once the
magnetron gets to the threshold voltage, it likes to
run at a constant volage. The capacitor source is
better at supplying this as part of the sine wave.
If you try to feed it with a fixed voltage, it will
destroy the tube. The capacitor works like a current
limiting resistor without the power loss.
Dwight
Q: Current C compilers are written in C.
What was the FIRST C compiler written in?
--
PDP-11 assembly language. You can look at the sources in the early
Unix archives, or....
--
From: Dennis Ritchie <dmr(a)bell-labs.com>
Newsgroups: comp.lang.c,comp.std.c,alt.folklore.computers
Subject: A primeval C compiler
Date: Thu, 29 Jul 1999 06:43:22 +0100
Organization: Bell Labs, Lucent Technologies
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I finally prepared another fossil for museum exhibition: from DECtapes
written
in 1972-73, there are exhumed C compilers (including source) to show
what
the very early stages of the language were like. This was a highly
transitional stage; for example, the earlier one anticipates a "long"
type, but doesn't have struct; the 6-months-later compiler implements
struct, but reuses long's slot in the type table.
http://www.cs.bell-labs.com/~dmr/primevalC.html
Dennis
>> wired the fan and magnetron together ... and controlled it with
>> an ordinary wall light switch
> I wouldn't have done this.
I would have used an egg timer switch (one that turns off after a
pre set time) but otherwise it sounds a reasonable fix.
> I know how, just about every part of, a microwave oven works and
Then you'll know why the HV supply is almost invariably voltage
doubled AC and not rectified and smothed DC.
> Also, I doubt that a normal wall light switch is rated for that
> large of an inductive load.
A microwave oven is a resistive load and most light switches (in the
uk at least) are rated adequately to switch a microwave (1.2KW for a
600W rated oven).
Lee.
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