test-drb August 2016

test-drb@ccmp.vtda.org

175 participants
281 discussions

by shadoooo＠gmail.com

Hello Andreas, nice to see you here from time to time. I too have two TSZ07, but both had problems with the PSU after some time of good working condition. The problem was always related, as indirect cause, to bad electrolytic capacitors, however the effect was always bad. The first one in the end became somehow over-stressed and had a transistor burned to short circuit; replaced the transistor, and all the capacitors, it was ok. After the repair operation, one of the motors lost the magnet inside, so I had to dismount it, open it carefully, put the magnet in place with wood parts to keep it in the right position, reglue the magnet with acrylic glue, remount. Worked! The second one began suddenly to oscillate badly, so on the 5V output there were peaks from 0V to 15-20V... It remained in the bad state for just 3-5 seconds, then I turned on 220V. Too bad, a microprocessor on the control board was fried. As I didn't find any schematic at the time (and not one so far), it took me a life with the bare oscilloscope to understand which component was defective, ordered it form the US, desoldered with hot air, resoldered, et voila, it became to life again... Worked, but I paid more for the repair / components than what I paid for the drive... I know also Holm has such a drive, again problems with the PSU... overheating. So be warned: replace all the relevant capacitors before operate the drive, to avoid problems. If you want and have some patience, I could take some pictures to show you what parts are delicate and what not. The PSU inside has two boards, one is high-voltage stage, the other has the main transformer and the low-voltage stage. It produces IIRC -12V, +5V (standby), +5V (high current), +12V, +37V. To test the PSU alone, you need to connect a resistor between two pins of a connector (I should double-check in case you want to know), otherwise it will not power-up, only standby voltage will be present, but it's not supplied by the switching high-power circuit. I recommend a test of one hour or more with load resistors (or lamps) and voltage monitoring to test the effective operation. Let me know if you need some help. (out of band data): do you have some information about trips to Munchen or somewhere in Bayern or Osterreich? Didn't heard of you anymore lately... We still have the drive swap to organize! Please let me know. Thanks Andrea

8 years, 4 months

Tape imaging

by couryhouse＠aol.com

Have the tape sets from the phx univac operations center that need to be imaged some day!Ed# Sent from my Verizon, Samsung Galaxy smartphone -------- Original message -------- From: Al Kossow <aek at bitsavers.org> Date: 8/10/16 17:10 (GMT-07:00) To: cctech at classiccmp.org, "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: Tape imaging Related, since it hasn't been mentioned on this list. Tom Hunter just got a release from CDC for the use of CDC software for non-commercial use, so any CDC tapes out in the wild are going to be of great interest. On 8/10/16 6:22 AM, aswood at t-online.de wrote: > Now I do have a big pile of CDC, DEC, HP, Convex and IBM tapes and I'd like to create tape images to file to save the tapes content.

8 years, 4 months

"RAM Drives" Elite 5H/10H Hard Drives for Apple ][

by marvin＠west.net

I ran across a manual from "Ram Drives" company that apparently made hard drives. They were based in Goleta, CA (just north of Santa Barbara) which is what really caught my attention. My *guess* is they made/provided hard drives to Lobo Drives for their hard drive/floppy disk combination. I *think* I have either two or three of these units, but am unwilling to power them up without knowing a LOT more about how to do it safely. Because I believe they came from Lobo Drives, I suspect they may have a lot of interesting source code/programs that Lobo dealt with. Long way of asking, has anyone heard of "Ram Drives" company based in Goleta, CA and have any more information on them?

8 years, 4 months

good news from me

by cctalk-bounces＠classiccmp.org

Hi friend! I wanted to tell you something really nice, please read it here <http://compare.kitefamily.us/aezymg> Hope this helps, cctalk-bounces at classiccmp.org

8 years, 4 months

dfitoimd: decoding Intel M2FM floppy flux images (was Re: Intel 432 floppy flux images for decoding)

by spacewar＠gmail.com

Because the cwtool support for Intel M2FM floppy disk flux images isn't publicly available, I've written a crude Python 3 program for converting such images (in DFI format) to ImageDisk images, and put it on github: https://github.com/brouhaha/dfitoimd My ADPLL data separator has parameters to control the proportions of frequency adjustment and instantaneous phase adjustment that are done at each flux transition. I've experimented with the parameters quite a bit, but it's still not good enough to reliably recover all sectors >from the disk images that started this thread. The default parameters are currently 0.5% frequency adjustment and 10% instantaneous phase adjustment. I was actually fairly surprised that I didn't get better results with more frequency adjustment and less instantaneous phase adjustment. It's entirely possible that my algorithm isn't very good. The code can handle normal IBM 3740 single-density FM format as well, though there are other published programs that already do that. There's a start at code for IBM System/34 double-density MFM format also, but it hasn't been tested at all as I don't happen to have any suitable DFI images. The dfitoimd program is quite slow; on a typical Intel M2FM image with two revolutions per track and 25 MHz sampling, it takes 64 seconds on a 4.0 GHz AMD CPU. I'm pretty sure that rewriting it in C/C++/C# or the like would make it much faster, but I specifically chose Python as I find it easier to experiment with the algorithms.

8 years, 4 months

Atlanta Open House tomorrow!!

by jwest＠classiccmp.org

I'm posting this on behalf of Cindy at Elecplus I can't post to cctalk when I am away from home. I am in Atlanta, and the owner of the warehouse hs agreed to let people come in tomorrow. Please can you post the following for me? First come first served, no shipping on the really cheap items. Model M 101/103 terminal keyboards $10 each, no cracked cases, may not have complete caps. Hundreds of keyboards for other terminals starting at $30 each, tested and complete. A full pallet of AEK 1 and 2 keyboards More expensive items include a Burroughs keyboard, complete and in good condition, a 1978 terminal in working condition, and the following terminals/keyboards, tested, no screen burn, keyboards are complete. DEC VT100 (no keyboards), 220, 320, 420.Wyse 50 and 60 with keyboards. Qume 62 and 101+ with keyboards.Link MC2 and 3 with keyboards. ADDS 4000 with keyboards. HP 700/22, 700/43, 700/60, 700/90, 700/92, 700/94, 700/96 with keyboards. LOTS of working vintage test equip. Some pics are here: <https://drive.google.com/open?id=0BxqLDyoLYuCKbkEwdmlST2lKaUU> https://drive.google.com/open?id=0BxqLDyoLYuCKbkEwdmlST2lKaUU Thank you! Cindy

8 years, 4 months

HP 110 AC Adapter

by COURYHOUSE＠aol.com

and with the right hil interface card can be used with hp-150 also. Ed# _www.smecc.org_ (http://www.smecc.org) In a message dated 8/10/2016 1:56:14 P.M. US Mountain Standard Time, Thanks (and thanks also to Rik for his input). The appropriate adapter is reasonably cheap on eBay ($20 with shipping) so I have one on its way. I've wanted an HP 110 for awhile (but never went out of my way to get one) so this should be fun to play with. And the 9114 drive that came with it can also be used with my HP-75, so that'll be cool as well. Thanks for the tips! - Josh

8 years, 4 months

HP 110 AC Adapter

by Martin.Hepperle＠MH-AeroTools.de

Josh, for testing you can also remove the battery and connect a 6V DC power supply to the computer. Under the battery cover there is also a picofuse which may be blown if someone was tinkering with the machine before. The HP 110 is interesting if you want to play with HP-IL - it has some BIOS routines to control the HP-IL. The other remarkable thing is that he has MS-DOS in ROM and all data on RAM disks m(which is rather limited, though). Ideally you would also want a 9114 3-1/2" floppy disk drive for it. If the computer works, you can rebuild the battery pack. The lead cells are still available e.g. under the name Hawker Enersys Cyclone 2V/2.5Ah. You can use 3 single cells (about 7$ each) and make them into a pack. Good luck Martin

8 years, 4 months

the value of old test and repair equipment

by sales＠elecplus.com

I had to pass up a large qty of old test equip at the recycler last time because they wanted too much for it. For instance, an old HP signal generator would have cost me $25, with no way to test it, and no guarantees that it was complete or working. So my question is, does as-is old test and repair equip that won't be particularly cheap have interest to you guys? Cindy Croxton Electronics Plus 500 Pershing Ave. Kerrville, TX 78028 830-370-3239 cell sales at elecplus.com AOL IM elcpls

8 years, 4 months

Photo album and video from VCF West

by jwsmail＠jwsss.com

https://goo.gl/photos/KdnDMBHeryMZqctV9 Youtube Channel playlist of videos. Some walking around Saturday morning before the show, Charles Anthony's exhibit. Also a fellow who dropped by after my buying a PDP 11/34 and was one of the engineers. I recorded an impromptu interview with him. https://www.youtube.com/watch?v=UtmVGeVhr7A&list=PL5NK70kdq3-JGwb_8GXFN5SqD… Sherman Foy and I had a great time attending and participating in the event this year. Thanks to the organizers, staff and volunteers that were there to put it on. Thanks Jim

8 years, 4 months

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test-drb August 2016