Repair Workshop 2023-01-14 & 15
Seems like everyone had fun this past weekend with the repair workshop. The usual suspects were there. Lots of interesting stuff getting fixed. David Gesswein repaired the VCF Museum's Xerox as well as the Sol-20. Thanks so much Dave! One lady came who needed picture files recovered from her early 2000's Macintosh. Dan helped her to recover and transfer most of them. Bill Dromgoole worked on the Univac a bit. Thomas worked on the Iris Personal as well as The Philips CD-ROM. Supposedly this is the first CD-ROM drive ever made. Very cool. For dinner Saturday night we split into two groups half went to Brick House Tap & Tavern, the other half went to MJs. Both were good. Sunday night we tried a new place Patrick's Grill and the 8 of us really liked it. So I will make reservations next month for this place. Anyone else want to chime in on what they worked on? ========================================= Jeff Brace VCF National Board Member Chairman & Vice President Vintage Computer Festival East Showrunner Vintage Computer Federation is a 501c3 charity https://vcfed.org/ <http://www.vcfed.org/> jeffrey@vcfed.org
This was one of the better workshops in recent memory, I had a great time. As is typical I ended up working on a bunch of little things. I got in late Friday night as I'm pretty far out of town and fiddled around with a free Sony VCR which I eventually condemned due to impossible to repair cap corrosion damage on a ceramic hybrid module in the video path. I also brought an older Trinitron TV which I cleaned up, fixed and calibrated to give to Ian L as he needed a good looking set with composite. For the other Ian I brought a handful of boat anchor tube scopes and a Packard Bell color TV to downsize a little bit. On Saturday I poked around a black and white Philco-Ford TV and was able to get it to produce a really crappy, inverted picture (after blowing up one of my clip leads when the main filter cap shorted). It uses a bunch of early and unreliable epoxy dome transistors in the IF and video path so my guess is one of them is bad, but I didn't end up having time to troubleshoot any further. Sunday I mostly helped Thomas out with museum stuff, I recapped the boardset out of the Philips CD-ROM drive and got a list of caps to buy for the Personal Iris power supply. It has a fair bit of cap corrosion damage as is typical in those systems but I think it will be repairable, I just need to get the parts and spend some stripping & cleaning it down the road. I also fixed one of the CDL's power strips which may or may not have blown up due to some shenanigans involving plugging caps into the wall outlet...but that's neither here nor there ;) +1 for going back to Patrick's Grill, the food was great and very reasonably priced as far as the 2023 economy is going. Although I personally thought it was hilarious watching the Sunday Night Football crowd go nuts I think it might be for the best if we reschedule to some other time though! CJ On Mon, Jan 16, 2023 at 8:43 PM Jeffrey Brace via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Seems like everyone had fun this past weekend with the repair workshop. The usual suspects were there. Lots of interesting stuff getting fixed.
David Gesswein repaired the VCF Museum's Xerox as well as the Sol-20. Thanks so much Dave!
One lady came who needed picture files recovered from her early 2000's Macintosh. Dan helped her to recover and transfer most of them.
Bill Dromgoole worked on the Univac a bit.
Thomas worked on the Iris Personal as well as The Philips CD-ROM. Supposedly this is the first CD-ROM drive ever made. Very cool.
For dinner Saturday night we split into two groups half went to Brick House Tap & Tavern, the other half went to MJs. Both were good. Sunday night we tried a new place Patrick's Grill and the 8 of us really liked it. So I will make reservations next month for this place.
Anyone else want to chime in on what they worked on?
========================================= Jeff Brace VCF National Board Member Chairman & Vice President Vintage Computer Festival East Showrunner Vintage Computer Federation is a 501c3 charity https://vcfed.org/ <http://www.vcfed.org/> jeffrey@vcfed.org
Just got done looking at Patrick's menu. Looks like a good substitute for Main Street... and looks rather easy to get to from Infoage. I see they have a cajun Bleu Cheese Burger, which is probably similar to the Black and Bleu Burger I regularly got at Main Street. I also see Patrrick's has flatbread pizzas, something I like to try out from time to time at various restaurants who serve them. My weekend at the Workshop started a little later than usual, as I arrived later than normal. I brought a set of TypeStore word processing devices which are designed to work with the IBM Wheelwriter or IBM Quietwriter to extend the functionality of those typewriters, through hardware, to a full screen CRT based interactive word processing system. I had three of them, which consisted of a main unit and an amber CRT. With a little poking around and Ian P's help, we were able to get them to power up. Normally they do not power up unless properly hooked up to the aforementioned IBM typewriters through their Feature Connector. Problem is, there is ABSOLUTELY ZERO documentation on the operation of these TypeStore devices, other than what I may have posted on my blog since I acquired them. Ian noticed that the Wheelwriter's connection probably causes a solid state relay to activate, thus switching on the system and monitor. When we bypassed that, the screen powered up and we were greeted with a "CODE 5 TO GO ONLINE" on the CRT. This means that you must press CODE+5 on the Wheelwriter to initiate the word processing system. We were unable to do that. The best that could be figured out is that the DB9 "DATA" connector on the TypeStore must contain the signal and bus lines fed from the feature connector of the Wheelwriter. But without documentation, we don't know which line goes where, and I had no pre-made cables for it. There are arduino projects out there that interface with a Wheelwriter feature connector for other uses, so if I can figure out the DB9 pinout, I may be able to use an Arduino to mimic Wheelwriter activity. Connor did me a favor and brought a Wheelwriter he had to the workshop, but unfortunately, it turned out to be a "Personal Wheelwriter", with an unknown feature connector status. After opening it up to look at the circuit board, it appeared to lack the electronics for the feature connector. This is probably why it was branded a "personal" Wheelwriter. It couldn't be connected to the TypeStore. Saturday, I helped a new member, Steve Lowrey, troubleshoot his recently acquired SX-64. Blank screen, solid disk drive light, and no blind command activity. Dead test carts didn't work, either. He had a breadbin C64 with all the main chips socketed, so we were able to test every main chip in the SX-64 to determine that they were all good, except for the PLA. After swapping PLAs from the breadbin, and also trying out my PLAnkton, we still couldn't get the SX-64 running. We exhausted all of the common checklist items for failure, and the next step is to replace the RAM and see what happens. Those parts are on order for the February Workshop. I then worked on the VTech Laser 310 I got at the Festivus swapmeet. It had a garbage screen and stuck keys when I first tested it. After a horrendous time of disassembling it and working through 15+ points of solder involving just the shielding wires and tabs, I finally got it down to the main board and the keyboard... which was still attached because they soldered BOTH ends of the ribbon cable to their respective boards. However, in its disassembled state, the computer powered up fine. I reassembled the entire kit and it still continued to work. Easy fix, I suppose. Oh... and I also brought special recipe booze that apparently was quite the attraction among the night owls of the Workshop. 😎 Jeff Salzman On Tue, Jan 17, 2023 at 3:00 PM CJ Reha via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
This was one of the better workshops in recent memory, I had a great time. As is typical I ended up working on a bunch of little things. I got in late Friday night as I'm pretty far out of town and fiddled around with a free Sony VCR which I eventually condemned due to impossible to repair cap corrosion damage on a ceramic hybrid module in the video path. I also brought an older Trinitron TV which I cleaned up, fixed and calibrated to give to Ian L as he needed a good looking set with composite. For the other Ian I brought a handful of boat anchor tube scopes and a Packard Bell color TV to downsize a little bit.
On Saturday I poked around a black and white Philco-Ford TV and was able to get it to produce a really crappy, inverted picture (after blowing up one of my clip leads when the main filter cap shorted). It uses a bunch of early and unreliable epoxy dome transistors in the IF and video path so my guess is one of them is bad, but I didn't end up having time to troubleshoot any further. Sunday I mostly helped Thomas out with museum stuff, I recapped the boardset out of the Philips CD-ROM drive and got a list of caps to buy for the Personal Iris power supply. It has a fair bit of cap corrosion damage as is typical in those systems but I think it will be repairable, I just need to get the parts and spend some stripping & cleaning it down the road. I also fixed one of the CDL's power strips which may or may not have blown up due to some shenanigans involving plugging caps into the wall outlet...but that's neither here nor there ;)
+1 for going back to Patrick's Grill, the food was great and very reasonably priced as far as the 2023 economy is going. Although I personally thought it was hilarious watching the Sunday Night Football crowd go nuts I think it might be for the best if we reschedule to some other time though!
CJ
On Mon, Jan 16, 2023 at 8:43 PM Jeffrey Brace via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Seems like everyone had fun this past weekend with the repair workshop. The usual suspects were there. Lots of interesting stuff getting fixed.
David Gesswein repaired the VCF Museum's Xerox as well as the Sol-20. Thanks so much Dave!
One lady came who needed picture files recovered from her early 2000's Macintosh. Dan helped her to recover and transfer most of them.
Bill Dromgoole worked on the Univac a bit.
Thomas worked on the Iris Personal as well as The Philips CD-ROM. Supposedly this is the first CD-ROM drive ever made. Very cool.
For dinner Saturday night we split into two groups half went to Brick House Tap & Tavern, the other half went to MJs. Both were good. Sunday night we tried a new place Patrick's Grill and the 8 of us really liked it. So I will make reservations next month for this place.
Anyone else want to chime in on what they worked on?
========================================= Jeff Brace VCF National Board Member Chairman & Vice President Vintage Computer Festival East Showrunner Vintage Computer Federation is a 501c3 charity https://vcfed.org/ <http://www.vcfed.org/> jeffrey@vcfed.org
This workshop was fairly productive on this front as well. Friday night I arrived, accidentally stumbled into the Antique Radio Club, joined their club, and bought some junk from their members only auction. After finding my way back to CDL I worked on repairing a Zenith TV I pulled from the side of the road. It only had coax, but someone from Long Island whose name is evading me was more than happy to take it home for some vintage gaming event they hold. Recapped and ready to go by the end of the day Saturday. Saturday after finishing up the TV I worked on a couple old radios I picked up from the Antique Radio Club. An old 1939 RCA 94BP1 Battery powered AM radio and a home brew regen receiver. Midway through the day Bart asked me to give him a hand and found all the bad solder joints on the museum’s Mac’s analog board. I spent the later half of the day trying to build an audio amplifier for a speaker, but made an oscillator instead and scrapped the idea of mixing Hollow and solid state electronics We also had a very productive docent meeting before dinner. I was in the Brick House crowd and we had a good time there. Sunday was mostly just cleaning up, tinkering and joking around. I also stopped by the museum for a little while to catch up with everyone with a few others on the way to the warehouse. On Sunday, Ian P. pulled from the trash an old Philips radio we called a cromulent junk box. Surprisingly, soldering in 2 random filters, she fired right up. We were all waiting for the Loud earth shattering Kaboom, but it ended up earning its keep. At the end of the day He gave it to me since he didn't want to lug it home. I looked it up and apparently it's fairly rare, but not very sought after. The 536AN was made by Philips when they escaped the Netherlands in 1941 and only made until the US entered WWI so not much info is available, but I found this site on a related model https://people.ohio.edu/postr/bapix/Phil436AN.htm I brought it home and cleaned it and it came back pretty nice, just gotta reglue some veneer. I also enjoyed Patrick's. It's the only pub I know of where I can get a French dip with horseradish for under 15 bucks. Thank you CJ for the Trinitron. The picture on it is very crisp and clear. And for the capacitors from the Emerson TV! Looking forward to next month! Thanks! -Ian L. On Mon, Jan 16, 2023 at 20:43 Jeffrey Brace via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Seems like everyone had fun this past weekend with the repair workshop. The usual suspects were there. Lots of interesting stuff getting fixed.
David Gesswein repaired the VCF Museum's Xerox as well as the Sol-20. Thanks so much Dave!
One lady came who needed picture files recovered from her early 2000's Macintosh. Dan helped her to recover and transfer most of them.
Bill Dromgoole worked on the Univac a bit.
Thomas worked on the Iris Personal as well as The Philips CD-ROM. Supposedly this is the first CD-ROM drive ever made. Very cool.
For dinner Saturday night we split into two groups half went to Brick House Tap & Tavern, the other half went to MJs. Both were good. Sunday night we tried a new place Patrick's Grill and the 8 of us really liked it. So I will make reservations next month for this place.
Anyone else want to chime in on what they worked on?
========================================= Jeff Brace VCF National Board Member Chairman & Vice President Vintage Computer Festival East Showrunner Vintage Computer Federation is a 501c3 charity https://vcfed.org/ <http://www.vcfed.org/> jeffrey@vcfed.org
My standard tome report. Summary: As Herb posted we read his hard drive. With a couple reads got down to only 2 bad sectors. Since I forgot cables we looked for a machine we could borrow cables from in the warehouse. Found a Gimix with hard drive. Pulled the drive also to read as long as we had opened the machine. Heads were out of alignment with head 0 mostly unreadable. 80% recovery may be good for clay tablets but not terribly useful for a drive. Took drive home and was able to recover all content. Rewrote the drive with the contents so is good for now. Bearings sound ok. Moved on to Xerox. I had studied the schematics/documentation prior to event.
From last time the machine was ignoring the maintenance panel alt boot button and failing with RTC clock fault. The documentation showed that part of the logic on the IOP was powered by a separate always on power supply. That supply was bad caused by bad transformer on power distribution card. Swapped card and machine now functional. Used .25A, 1A, and 20A glass fuse from CDL stock. Thanks for having them.
Since had time left consulted with Crawford on what was next priority and he decided fixing the Sol-20 which was displaying pattern of junk characters on the screen. It had repeated problems with the socketed chips so I swapped the motherboard with another machine in the warehouse and it worked without having to do anything to it. Keyboard wasn't working properly. Swapped U17 to fix it. Weren't able to load a program through the cassette port. Hoping operator error. TLDR; DRIVES: MFM drives as they age tend to loose head alignment. Herbs drive head 0 looked to be slightly off since it had 110 ECC corrections and two bad sectors on it. None on the other heads. Using large number of retries got down to the two bad sectors. Drive was a Servo Quantum Q540 The Gimix drive head 0 had most of the sectors unreadable on every track. Seeked to the same cylinder as you changed heads you would see data from different cylinders. It appears something had twisted the head alignment. This I have seen frequently. Drive was stepper Seagate ST-225. I used this method to microstep the heads under my control and recovered all sectors. http://www.pdp8online.com/mfm/microstep/index.shtml I then rewrote the data and reread it to verify good. Had to do more than once before I got an error free read. Gimix is 6809 system running OS-9 Timesharing system Level II V1.1 http://www.bitsavers.org/pdf/gimix/Gimix_Catalog_Jun82.pdf I used https://toolshed.sourceforge.net/ToolShed.html to try to look at the image. It was able to read some of it but had problems. Top level directory listing at end. Needed to remove first two 256b sectors from image for toolshed to read image. dcheck shows lots of errors. Don't know if its version of filesystem or some issue with disk image. XEROX: In the Xerox on the power distribution board is a small 120V to 12V transformer. The 12VAC goes to the maintenance panel board where its converted to 5V to power some of the IOP logic and a clock to run the real time clock. The output was dead. Found the AC fuse was blown. To avoid using up fuse stock hooked up current limited variable supply to the 12VAC input to front panel and verified 5V good and current was 380 mA which was under the maximum of 500 mA. Running from this supply the alt boot switch was not recognized but the 501 fault still occurred since it wasn't getting the clock. Replaced fuse and transformer output was 12V unloaded and 8.3V loaded. When loaded the 5V dropped to 3.6V. No obvious fault found to cause low voltages so pulled board from warehouse machine. It was a different version with several more "fuses". Two of the fuses were brass rods. Looks like they were cut off on a lathe so likely original. The PCB for one wasn't labeled with any current rating. The other was labeled 6A. The board that was in museum machine had direct trace connections for the rod "fuses". A third fuse F6 was not installed. Since it also was a trace on the other board I put a 20A fuse in. Was labeled 6A. I assume Xerox found the fuses were causing too large a drop on the DC outputs so replaced them with the brass rod. The F3 1A fuse was bad and I replaced it. With this board transformer output is 15.2V no load, 13.2V under load and 5V stayed 5V under load. Machine functional again. Original purpose of this supply was to keep the clock running when the machine was turned off like modern computers have batteries. Looks like Bel/Signal DST-4-24 transformer will replace the bad transformer. I'll get one on my next parts order and repair the board. The bad board is Dale IPL-2329-25. That part number doesn't seem to match so may have been slight change to Dale PLD-54-24 that looks similar but no longer available. The board currently in the machine is Signal but didn't have a part number I could see on it. SOL: Screen had various character patterns sometimes changing sometimes static. I little searching said with no personality module (EPROMS) and no memory board installed screen should fill with repeating 09. It didn't. Disassembled enough to get to motherboard and poking at chips changed pattern. After wiggling a couple near the S100 connector I got the 09 pattern. Chips could be pulled from sockets with fingers. Probably need to replace sockets to make that board reliable. Haven't dealt with this enough to know if any contact treatments will work long term. Pulled motherboard from third warehouse Sol in cardboard box with newspaper padding labeled for Jeffery Brace. After swapping motherboard thought computer operated properly. Boxed Sol looks pretty good except for an eye bolt through the wood side. I did not try to power that machine on. The museum Sol motherboard is in the warehouse Sol. Took it back to museum and hooked up. Tried to follow procedure to load program and keyboard won't respond to special keys upper case, shift, shift lock, local. Can't use EPROM monitor in lower case. Took back to CDL and tried keyboard from warehouse Sol but it didn't respond to any keys. May be bad foam pads. Looked at keyboard schematic and traced signals. The column select for those keys wasn't being generated. Swapped U17 between the two keyboard and now shift keys worked. U17 was generating some output but not for that key row. I think I tried reseating the chip before swapping so chip is likely bad. Was late so didn't have time to investigate further why when trying to load from cassette port using iPod the Sol gave an error. Gimix directory: Directory of /tmp/t.ext, CMDS SYS DEFS SOURCE PROC C BASIC OS9 PASCAL2 RAMDISK SLEUTH SPOOL KERMIT DSTAR SORTS ADVENTURE UTIL CMMF9 SERIOUS FC107 GIMIX SERVOS ELIT LPTEST GPIB mtrx.p oldstart dsv.p prom.p cmp.cfp cmp.x h.p DART M68 MODEM m68nov.pat upstart dart.p startup.9600 ATS modem.c startup newstart flist TEMP cfp.9 DAN JUNK TEST cfp.7 FASFAX PUNK Says disk was created 05/14/1987 22:03
Where would you categorize and place a brass rod fuse in this collection? Fuse diagram <https://hvac-talk.com/vbb/attachment.php?attachmentid=623661&d=1442927636> On Wed, Jan 18, 2023 at 9:36 AM David Gesswein via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Two of the fuses were brass rods. Looks like they were cut off on a lathe so likely original. The PCB for one wasn't labeled with any current rating. The other was labeled 6A. The board that was in museum machine had direct trace connections for the rod "fuses". A third fuse F6 was not installed. Since
Penny for your thoughts Sent from: My extremely complicated, hand held electronic device.
On Jan 18, 2023, at 11:27 AM, Jeff S via vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> wrote:
Where would you categorize and place a brass rod fuse in this collection?
Fuse diagram <https://hvac-talk.com/vbb/attachment.php?attachmentid=623661&d=1442927636>
On Wed, Jan 18, 2023 at 9:36 AM David Gesswein via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Two of the fuses were brass rods. Looks like they were cut off on a lathe so likely original. The PCB for one wasn't labeled with any current rating. The other was labeled 6A. The board that was in museum machine had direct trace connections for the rod "fuses". A third fuse F6 was not installed. Since
coffee -> keyboard On 1/18/23 11:26, Jeff S via vcf-midatlantic wrote:
Where would you categorize and place a brass rod fuse in this collection?
Fuse diagram <https://hvac-talk.com/vbb/attachment.php?attachmentid=623661&d=1442927636>
On Wed, Jan 18, 2023 at 9:36 AM David Gesswein via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Two of the fuses were brass rods. Looks like they were cut off on a lathe so likely original. The PCB for one wasn't labeled with any current rating. The other was labeled 6A. The board that was in museum machine had direct trace connections for the rod "fuses". A third fuse F6 was not installed. Since
-- Dave McGuire, AK4HZ New Kensington, PA
Between the nail and the bold, to my eye. :) On 1/18/2023 11:26 AM, Jeff S via vcf-midatlantic wrote:
Where would you categorize and place a brass rod fuse in this collection?
Fuse diagram <https://hvac-talk.com/vbb/attachment.php?attachmentid=623661&d=1442927636>
On Wed, Jan 18, 2023 at 9:36 AM David Gesswein via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Two of the fuses were brass rods. Looks like they were cut off on a lathe so likely original. The PCB for one wasn't labeled with any current rating. The other was labeled 6A. The board that was in museum machine had direct trace connections for the rod "fuses". A third fuse F6 was not installed. Since
On 1/18/23 16:33, Douglas Crawford via vcf-midatlantic wrote:
Between the nail and the bold, to my eye. :)
Bold? Bullet? or misspelling of bolt? -- Linux Home Automation Neil Cherry kd2zrq@linuxha.com http://www.linuxha.com/ Main site http://linuxha.blogspot.com/ My HA Blog Author of: Linux Smart Homes For Dummies KD2ZRQ
I had the pleasure of observing all the buzz! There were a number of really remarkable accomplishments that were worthy of capturing in the moment. Many deserved to be captured for posterity. I'm going to consider afresh how maybe to capture the highlights of a workshop or maybe broadcast it. Jeff B had expressed interest in this in the past I think. One of the coolest moments was when Ian P. took a crusty ancient radio discarded on campus and with a few deft strokes of a soldering iron had the radio playing. Related to the museum, Dave Gesswein got the Xerox Star back in operation. Next we might work on the warehouse Star so that we have a working spare for zero Star museum downtime. Its a really important part of our user interface presentation. Dave also worked on our SOL and as he said, swapped boards and parts. Related, we are nearing having operational computers in our kit and S100 area, all of which have been "dark" exhibits for quite some time. Specifically, the Scelbi, and Altair are being worked on by Corey. ROM programs are going to be in the Altair and we will do tape load demos too. Bart and Ian L broke open our long unreliable Mac128k and fixed cracked solder joints and "righted that ship". As someone else mentioned Bill Dromgoole continued his work to iron out problems in the UNIVAC 1219. Glad everyone had a good time and thanks very very much to those that contributed to the VCF Museum artifacts. It was a pleasure spending time with everyone. - DC On 1/16/2023 8:42 PM, Jeffrey Brace via vcf-midatlantic wrote:
Seems like everyone had fun this past weekend with the repair workshop. The usual suspects were there. Lots of interesting stuff getting fixed.
David Gesswein repaired the VCF Museum's Xerox as well as the Sol-20. Thanks so much Dave!
One lady came who needed picture files recovered from her early 2000's Macintosh. Dan helped her to recover and transfer most of them.
Bill Dromgoole worked on the Univac a bit.
Thomas worked on the Iris Personal as well as The Philips CD-ROM. Supposedly this is the first CD-ROM drive ever made. Very cool.
For dinner Saturday night we split into two groups half went to Brick House Tap & Tavern, the other half went to MJs. Both were good. Sunday night we tried a new place Patrick's Grill and the 8 of us really liked it. So I will make reservations next month for this place.
Anyone else want to chime in on what they worked on?
========================================= Jeff Brace VCF National Board Member Chairman & Vice President Vintage Computer Festival East Showrunner Vintage Computer Federation is a 501c3 charity https://vcfed.org/ <http://www.vcfed.org/> jeffrey@vcfed.org
participants (9)
-
CJ Reha -
Dave McGuire -
David Gesswein -
Douglas Crawford -
Ian Litchfield -
Jeff S -
Jeffrey Brace -
Neil Cherry -
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