I'm cleaning/refurbing a TRS-80 Model 4 I picked up at VCFe that was
in dirty-but-mostly-working shape. I've completely dismantled,
cleaned and reassembled the keyboard, I fixed the bad cable to the
floppy controller, I cleaned and lubed the TM-100-1 floppy drive, and
had it all nice and working, then I bumped the power strip it was
plugged into and the momentary surge took out the electronics on the
floppy drive. I swapped it out with another TM-100-1 unit (borrowed
>from a Model 1) and it's booting again, but when using this toasted
drive as :1, I get either an ERROR 3 or ERROR 4 from TRSDOS 1.3 (my
primary testing disk for the moment). The drive still seeks and spins
but it won't read disks that it used to read before the power hit.
I also have an original NEWDOS/80 disk and a copied MULTIDOS disk. I
have not yet fixed up a PC with a 40-track 5.25" drive for making
fresh disks, but it's on the list of solution paths.
I have the TM-100 service manual PDF (which includes schematics), so
it shouldn't be difficult to work through the functional subsystems of
the drive electronics. My question is are there any specific issues
with the parts on the TM-100 PCB to look for? There are a handful of
reasonably common ICs, and dozens of discrete components. Of course I
can trace through each section looking for where the results are
unexpected, but for such a common thing as a TM-100, perhaps there are
known pain points and perhaps someone here has repaired a few and
could highlight what parts might be "fragile".
Additionally, for a testing framework to poke signals through the
drive for debugging during the repair, what's a good platform? A PC
running MS-DOS? The TRS-80 Model 4 itself? Besides doing
directories, are there any good bits of software anyone can recommend
for exercising floppy drives on a sub-system-by-subsystem basis?
(move the heads, do a read, do a write...)
I expect like the last repair (shorted tantalum filter cap), this
repair is going to be a small number of components. Parts of the
drive are known to work - the motor turns on and off when it should,
and it does seek back to track zero when manually moved off of track
zero prior to doing a DIR :1 or when booting it as :0. At first
glance, something appears to be toasted in the read electronics.
It's not impossible to find another TM-100-1 or replace it with a
TM-100-2 (more common, owing to its appearance in the IBM 5150 PC),
but I'd like to just repair this one and get back to TRS-80 hacking.
Thanks for any tips or pointers.
Was working on some Drives this week, and took some pictures of it disassembled.
The prefilter was orange crumblefoam. I took a look at my NOS ones and they have
a greenish prefilter that still appears to be OK. The gasket going up to the plastic
basket that holds the pack is crublefoam as well. I'm going to try some 3/8" x 1/2"
Norprene foam strip as a replacement, with polyurethane glue over the seam.
The door latch and load lamp is driving me nuts. Dug out my extender card this morning
to try and figure out why the driver transistors aren't turning on. Tranistors, diodes
are fine, and the J9 board that drives it works in another drive.
(Waits for Jay's next email "This has been a test of the new auto banning system. Thank you.")
-------- Original message --------From: Alexandre Souza via cctalk <cctalk at classiccmp.org> Date: 4/27/17 1:58 PM (GMT-06:00) To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>, Jay West <jwest at classiccmp.org> Subject: Re: test, please ignore
This is a test, designed to provoke an emotional response
Enviado do meu Tele-Movel
On Apr 26, 2017 9:39 PM, "Jay West via cctalk" <cctalk at classiccmp.org>
> Don't need a response, please ignore.
IMMEDIATE RELEASE No. NR-145-17
April 26, 2017
Air Force Issues Challenge to ?Hack the Air Force?
The Air Force is inviting vetted computer security specialists from across
the U.S. and select partner nations to do their best to hack some of its
key public websites.
The initiative is part of the Cyber Secure campaign sponsored by the Air
Force?s Chief Information Office as a measure to further operationalize the
domain and leverage talent from both within and outside the Department of
The event expands on the DoD ?Hack the Pentagon? bug bounty program by
broadening the participation pool from U.S. citizens to include ?white hat?
hackers from the United Kingdom, Canada, Australia and New Zealand.
?This outside approach--drawing on the talent and expertise of our
citizens and partner-nation citizens--in identifying our security vulnerabilities
will help bolster our cybersecurity. We already aggressively conduct
exercises and 'red team' our public facing and critical websites. But this next
step throws open the doors and brings additional talent onto our cyber team,?
said Air Force Chief of Staff Gen. David Goldfein.
White hat hacking and crowdsourced security concepts are industry
standards that are used by small businesses and large corporations alike to better
secure their networks against malicious attacks. Bug bounty programs offer
paid bounties for all legitimate vulnerabilities reported.
?This is the first time the AF has opened up our networks to such a broad
scrutiny,? said Air Force Chief Information Security Officer Peter Kim. ?
We have malicious hackers trying to get into our systems every day. It will
be nice to have friendly hackers taking a shot and, most importantly,
showing us how to improve our cybersecurity and defense posture. The additional
participation from our partner nations greatly widens the variety of
experience available to find additional unique vulnerabilities.?
Kim made the announcement at a kick-off event held at the headquarters of
HackerOne, the contracted security consulting firm running the contest.
"The whole idea of 'security through obscurity' is completely backwards.
We need to understand where our weaknesses are in order to fix them, and
there is no better way than to open it up to the global hacker community,"
said Chris Lynch of the Defense Digital Service (DDS), an organization
comprised of industry experts incorporating critical private sector experience
across numerous digital challenges.
The competition for technical talent in both the public and private
sectors is fiercer than it has ever been according to Kim. The Air Force must
compete with companies like Facebook and Google for the best and brightest,
particularly in the science, technology, engineering, and math fields.
Keen to leverage private sector talent, the Air Force partnered with DDS
to launch the Air Force Digital Service team in January 2017, affording a
creative solution that turns that competition for talent into a partnership.
In fact, Acting Secretary of the Air Force Lisa S. Disbrow and Gen.
Goldfein visited the Defense Digital Service and Air Force Digital Service in
early April to discuss a variety of initiatives the Air Force can benefit
?We're mobilizing the best talent from across the nation and among partner
nations to help strengthen the Air Force's cyber defenses. It's an
exciting venture, one that will make us better, and one that focuses an
incredible pool of capabilities toward keeping our Air Force sites secure," said
Acting Secretary Disbrow.
The DoD?s ?Hack the Pentagon? initiative was launched by the Defense
Digital Service in April 2016 as the first bug bounty program employed by the
federal government. More than 1,400 hackers registered to participate in the
program. Nearly 200 reports were received within the first six hours of
the program?s launch, and $75,000 in total bounties was paid out to
Registration for the ?Hack the Air Force? event opens on May 15th on the
website. The contest opens on May 30th and ends on June 23rd. Military members and
government civilians are not eligible for compensation, but can
participate on-duty with supervisor approval.
Updates from the U.S. Department of Defense