test-drb April 2015

test-drb@ccmp.vtda.org

182 participants
220 discussions

by evan＠snarc.net

Hackaday sponsored our Friday "VCF East University" classes and they wrote many articles about us before, during, and after the show: hackaday.com/tag/vcf-east/ Ars Technica wrote a great story about "George" and more: http://arstechnica.com/gadgets/2015/04/ars-timetravels-through-vintage-comp… MARCH member Garret Nievin took this picture, which is sure to be a hit with DECheads :) http://snarc.net/k_at_pdps_taken_by_garrett_nievin.jpg Tweet-of-the-week: https://twitter.com/MalachyHasRisen/status/589823313037365248 2600's "Off the Hook" radio show interviewed me about VCF two weeks ago. They attended in their famous Bell Telephone van and then discussed the show on last night's OTH episode: http://www.2600.com/offthehook/2015/0415.html Jason Scott's pictures: https://m.flickr.com/#/photos/textfiles/sets/72157652032897002/ Chris L.'s pictures: http://imgur.com/a/XzVsD?gallery Bill D.'s pictures: http://www.vintagecomputer.net/vcf10/ Doug C.'s pictures: http://imgur.com/a/14z4q Many other blog posts, Tweets, etc. are out there in the intertubes. We encouraged people to use #vcfeast where possible.

9 years, 8 months

IMSAI chassis color/texture...

by dave＠661.org

On April 22, 2015 7:38:43 PM PDT, Bill Sudbrink <wh.sudbrink at verizon.net> wrote: > I remember a conversation about this subject from many > years ago that never came to any conclusion. Has anyone > discovered any "paint codes" or other definitive descriptions > for the finish on the upper case of an IMSAI? I'm thinking > of having my worst case (multiple scrapes and scratches, > several permanent stains) refinished. > > Bill S. I seem to recall Todd Fisher of imsai.net selling custom-mixed cans of "imsai blue" paint. -- David Griffith dave at 661.org

9 years, 8 months

Interesting drive failure...

by derschjo＠gmail.com

I'm attempting to dump an image of the Ridge 32/330's original SMD drive (A Fujitsu MK2322) -- I'd been running it off of a spare, because I didn't want to disturb what was on the original drive until I could back it up. Now that the spare has died I figured it would be an opportune time... The Ridge "DISCUTIL" tool (loaded from QIC) is pretty powerful, and amongst its weapons is the "DS" command which will dump a sector of the disk to screen, in ASCII HEX. The Ridge has been running for the past eight days dumping the entire 168mb disk, in HEX, at 9600 baud. Yes, I'm insane. Along the way I discovered that the integrity of the data on the disk is pretty poor. There are lots of bad sectors. In particular surfaces 2 and 3 are completely unreadable for all 823 cylinders, surfaces 4 and 8 are marginal most of the time. After a lot of retries I've managed to get most of everything (except for surfaces 2 and 3 which yield no data at all). So I figured that heads 2 and 3 are toast -- perhaps bad analog logic, maybe something in the digital logic that selects the head, maybe even bad heads, who knows. DISCUTIL also has a "FORMAT" command that will format individual cylinders, on a specified surface. So after I'd read out everything possible to save, I tried it on a cylinder (801) known to have trouble sectors, that also containing all zeros so I wouldn't wipe out anything vital. After doing a format on cyl 801, head 2 I could read all sectors on that cylinder/head without issue. Same with head 3, 4 and 8. Suspecting a possible addressing fault I tried reading every surface on cylinder 801 after formatting all surfaces on that cylinder, and they all read without issue. (I'd expect that if, for example, when I asked the disk to format surface 2 it actually formatted surface 5, then reading surface 5 later would fail due to an invalid sector header for surface 5...) So, I suppose this is somewhat good news in that I may be able to use the drive, but I wonder what would cause the data on the disk to fail in such a manner (and I'm still hesitant to reformat the drive without recovering stuff off of surfaces 2/3...) Any thoughts? - Josh

9 years, 8 months

Another mystery head quiz

by cclist＠sydex.com

I was goofing around with an old digicam (Fuji MX700)and wondered if I could stick it on the eyepiece of my old B&L Stereozoom inspection microscope. Aside from the obvious problem of using LEDs for illumination, it looks like it works. Maybe it's not time to toss the old camera. (FWIW, the illumination is a freebie 9-LED flashlight, which just happens to fit the scope stand--I run it from a old 4.5V cellphone charger. At any rate, who can identify the head in this photo: http://i.imgur.com/mN9v33b.jpg I'm pretty certain that I know. It's about 16mm square and is mounted on a small PCB with lead connections. --Chuck

9 years, 8 months

Interesting drive failure

by t.gardner＠computer.org

On 4/22/15 5:04 PM, David Gesswein wrote: > Head alignment off on those heads. Can the drive microstep or any > other way to change the head alignement? You might be able to recover > the data that way. Some SMD drives could microstep and some controllers implemented it. Not sure about yr drive or its controller. BTW, I did several searches for info on the Fujitsu drive without any luck. If u can get a utility to loop on reading a specific track and head then you can apply finger pressure to the top of the carriage to force the head slightly off track in either direction to see if it reads better in one direction or the other. Be careful with both pressure and location because if the servo decides it's lost it will probably do a recalibration which happens quickly and with force - could damage the finger. With an oscilloscope u can observe the raw head signal (differentially) and see if it increases in one direction or another. U can probably read single ended if u can figure out where is the output of the read preamplifier (might even be right next to the head stack). With a schematic, power supply and variable resistor u can inject an offset signal into the servo loop and move the heads off tract to the maximum head amplitude position. Again start low and slowly increase the injected signal. Tom

9 years, 8 months

Arlington, TX "vintage computer museum" closing, close-out sale

by mikew＠thecomputervalet.com

> On Apr 22, 2015, at 11:56 AM, John Foust <jfoust at threedee.com> wrote: > > http://dallas.craigslist.org/mdf/syd/4990079844.html I can't speak to the individual items and their relative condition. However, my sense is they know what they have and the prices are higher than what you'd typically find on eBay. I visited there a few weeks back. Cheers, Mike Whalen > On Apr 22, 2015, at 11:56 AM, John Foust <jfoust at threedee.com> wrote: > > > http://dallas.craigslist.org/mdf/syd/4990079844.html > > - John >

9 years, 8 months

IMSAI chassis color/texture...

by aek＠bitsavers.org

On 4/22/15 7:38 PM, Bill Sudbrink wrote: > I remember a conversation about this subject from many > years ago that never came to any conclusion. Has anyone > discovered any "paint codes" or other definitive descriptions > for the finish on the upper case of an IMSAI? I'm thinking > of having my worst case (multiple scrapes and scratches, > several permanent stains) refinished. > > Bill S. > > > > If you find an answer, I have one in need of it as well.

9 years, 8 months

Visual Basic Question

by mark＠markesystems.com

>> The phrase "standard Windows 16bit DLLs" means Windows 3.1 DLLs. Such >> DLL's no longer work in a modern windows. If they directly access the >> hardware then they will not work on any NT based windows such as >> Windows/2000, Windows/XP, Vista, or 7, 8 or 9. Nor will they work on any >> 64-Bit windows full stop. 64-Bit windows does not support 16-bit code. >> If you have a Windows/95, 98 or ME environment then the code may work. > >They should work with 32 bit versions of windows as the 16 bit thunking >layer is still present. YMMV of course. Actually, VB3 works perfectly well under all 32-bit versions of Windows up through XP; it breaks at Windows 7 (and presumably Vista). Under all the NT-based versions (NT, 2000, and XP), Windows launches a virtual machine call NTVDM.EXE (NT Virtual DOS Machine), upon which runs yet another emulator WOW.EXE (Windows on Windows). This latter emulator presents the non-preemptive message-passing architecture of Windows 3.1 to all the 16-bit Windows applications (like VB3) that run upon it. This actually worked remarkably well; I?ve personally supported an application for 20 years that is written in VB3, including adding new features all that time ? even a Web server! There was also a technique that allowed calling 32-bit DLLs from the 16-bit application. There were a couple of bugs, of course, but generally it was a very stable solution to supporting legacy code. There was even a work-around to NT?s rigorous defense of direct hardware access which continued to work through XP. Windows 7 broke all that. (Presumably Vista actually did, but I?ve never seen a Vista system in the wild...) ~~ Mark Moulding

9 years, 8 months

Looking for Sun 68k machines, from time to time...

by joerg.sigle＠jsigle.com

Dear list It may sound odd (maybe less to you than to other people...) - but from time to time I get sad that I don't have any Sun 3 around here (and no DECstation either). I guess it's an attempt to preserve some of the past by preserving things that belonged to it. So, I was just wondering whether you might know anyone who would like to part with one of these. Preferrably in Europe, so that shipment would not be prohibitive - and preferrably something like a 3/80 or 3/60 with keyboard and mouse, trading of speed vs. occupied space. But actually, first of all I'm interested whether there are any of these still around in my region at all. Thanks a lot for any reply of yours in advance! And kind regards! Joerg -- http://www.jsigle.com Have a lovely day...

9 years, 8 months

Teleprint TP-3328 ASR 33

by marco＠familie-rauhut.eu

Hello all together! At the moment i try to bring back a TTY from Teleprint to life. It is a TP-3328. A labeled Teletype ASR33. It looks like the original ASR 33. Differences are the missing off position on the on/off/local switch. The Motor of the ASR starts up at every key touch and stops after a letter ist printed. The Elektronic part at the right is also different. My problem is the current loop connection. The molex plug no. 2 and the terminal strip below did not exist in my tty like in the original ASR manuals described. Has any one information about the TTY`s current loop interface? Marco * Englisch - erkannt * Englisch * Deutsch * Englisch * Deutsch <javascript:void(0);>

9 years, 8 months

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test-drb April 2015