test-drb April 2017

test-drb@ccmp.vtda.org

169 participants
185 discussions

by ethan.dicks＠gmail.com

Hi, All, 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. -ethan

8 years

Reviving VT220?

by w9gb＠icloud.com

For your education, Google search "Flyback transformer" There are a number of rebuilders, replacements, and substations. B&H Electronics https://www.bhelectronics.com/products/dc-dc-power-products/isolated-flybac… Pactran http://pactran.com/why-pacific-transformer/?gclid=CNWWzLzVx9MCFQkaaQodop0BTQ greg Chicago Sent from iPhone 6s

8 years

Diablo 3x pictures

by aek＠bitsavers.org

Was working on some Drives this week, and took some pictures of it disassembled. http://bitsavers.trailing-edge.com/pdf/diablo/photos/Diablo_33F/ 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.

8 years

Anyone driving from the Midwest to VCF_SE this weekend?

by brain＠jbrain.com

I am flying in and wondering if someone had any extra room coming home (for parts, not me). Jim -- Jim Brain brain at jbrain.com www.jbrain.com

8 years

RA82 HDA

by shadoooo＠gmail.com

Hello, where are you located? If you are in EU, I'm interested. Thanks Andrea

8 years

test, please ignore

by barythrin＠gmail.com

(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> wrote: > Don't need a response, please ignore. > > > > J > >

8 years

Air Force Issues Challenge to “Hack the Air Force” 04/26/2017 04:10 PM CDT --

by COURYHOUSE＠aol.com

____________________________________ 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 Defense. 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 from. ?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 participating hackers. Registration for the ?Hack the Air Force? event opens on May 15th on the _HackerOne_ (http://links.govdelivery.com/track?type=click&enid =ZWFzPTEmbWFpbGluZ2lkPTIwMTcwNDI3LjcyNzk2MTYxJm1lc3NhZ2VpZD1NREItUFJELUJVTC0yMDE3MDQyNy43M jc5NjE2MSZkYXRhYmFzZWlkPTEwMDEmc2VyaWFsPTE3NDEwNDE5JmVtYWlsaWQ9Y291cnlob3VzZ UBhb2wuY29tJnVzZXJpZD1jb3VyeWhvdXNlQGFvbC5jb20mZmw9JmV4dHJhPU11bHRpdmFyaWF0Z UlkPSYmJg==&&&101&&&https://www.hackerone.com/?source=GovDelivery) 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

8 years

test, please ignore

by jwest＠classiccmp.org

Don't need a response, please ignore. J

8 years

Help identifying this old terminal

by sbolton＠bfree.on.ca

Anybody recognize what kind of terminal this is? I am assuming it is a terminal rather than a personal computer. Thoughts?

8 years

IBM 3420 x2 + 3803 for sale

by vpresher＠ddci.net

I am interested in your tape drives if you still have them.. Can you send photos of all components? Victor Presher 214-905-4447

8 years

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test-drb April 2017