Schedule July 2007
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Wed July 04 - general, Wed July 11 - general, Sat July 14 - 2nd Sat. - Volunteer Day Wed July 18 - general, Wed July 25 - general, Sat July 28 - 4th Sat.
E-mail received: Van Snyder DFT 5310, ... - Karl Bleher backplane power cracks - Allison Akbay Werner, Oregon shipment -
Wed July 04 - generalRon Williams will be there - so its an official work day ;-))
- Present were: Ron Williams, Bob Erickson, Judith Haemmerle, Ed Thelen. The building was otherwise empty.
- Ed Thelen was in Tuesday - and the newly patched Multiple Big Print demo program had a strange bug, the text that this version stored away in core for reuse on for multiple guest printouts was getting overlayed if there was more than 4000 characters of text.
I called Ron telling him of this bug, and he said there was still a problem involving the 8,000 memory boundary. Unfortunately, this did not exactly fit my bug as I started pouring text starting 3,000 up, and got a roll-over of the index register (X3=3,999) at memory location 7,000.
So today Ron (and a reluctant me ;-) continued to trouble shoot the 8,000 boundary problem. Ron had noted that at particular locations, moving characters down from say 8201, 8200, ... except as shown in Ron working paper, the next address was 199 instead of 8119. But at other address boundaries, the machine did just fine, as shown 8101, 8100, 8099, 8098. OK what was the machine trying to tell us??? I figured that the 8K bank and the 2 hundreds bit has a problem subtracting :-))
Ron said "right, and I think the problem is on this page" and soon guided my hand to the gate at the right of the paper clip. :-)) - With Ron around, life is so simple :-)))
- Note the red lines which Ron had already drawn tracing the problem - looks easy :-|
Well, OK - now the hard part! What is the text in the box? and what is the meaning of the text???
- We tease each other who owns Ron's magnifying equipment, two magnifying glasses. But now is the time to try to make out the hazy text. (The "originals" we received weren't any better. I had taken great pains to adjust the reproducing machine for best quality working copies for us to work with.)
The text you and I are interested in:
- "01" of the "01AC" means first 1401 cabinet,
- "A" of the "01AC" means top box,
- "8" of the "8E17" (it is not a "B") means 8th gate
- "E" of the "8E17" means column E, counting from hinge out
- - - (note empty A column)
- "17" of the "8E17" (a 7 not a 1, it slants) is card, counting down
The left image shows the inputs, there was no change in the output of the defective card. This is the card we used to replace the no output gate And here is the good output of the replacement card.
See how easy it is???
And Ron can now do a Storage Scan with out getting alarms :-)) Being continuously reset by this handy tooth pick :-)) And Tim Coslet has another (CJWF) card to fix - this one looks easy :-))
I have no idea if/how Bob "fixed?" the spring. Ron Williams said that Orchard Supply has a good stock of springs - but the did not make a trip.
Taking a break from the 1401, we now turn to Bob Erickson and Judith Haemmerle working on the 513 reproducing (and summary) punch. Bob and Judith had re-assembled the gear box, and hand cranked the machine. It did not work correctly - so the gear box cover comes off - again. Behind the Geneva gear, Bob found one of the clutch springs had been damaged :-(( I'm not sure I have the story correct, but there was a question in the re-assembly about the position of one of the cams while trying to get it all together. and something about a pivot adjustment to be done through a hole in one of the gears?
Here is (Bob's) copy of the IBM 514 Summary Punch - the physical punch mechanism is apparently identical with our 513. Looks as though I should make a shop copy !! and the outside of the gear case
E-mailed to me later - here is the "last shot of the day". The gear box cover has been reinstalled - again - and hopefully the machine will/does hand crank over just fine. That big selenoid operated the clutch (inside the gear box
- Back to the 1401 - the repair of the strange 8,000 decrement problem did not fix the newly patched Multiple Big Print demo problem :-(( Darn, not our lucky day.
Ron said that when you add or subtract something from an X Register, the X Register has to have a word mark in the high order position, as that is the B-Operand. (I had assumed that a word mark in either A or B operands terminated the operation.) So Ron helped me experiment. I put in a little three instruction through the front panel - I won't say how long to took to get my 10 thumbs working correctly.
After some experimentation, we found that Ron was correct :-((
- Ya know, It just ain't fair !!
So I patched the patched Multiple Big Print demo program to place word marks in the high characters of the X-Registers - but the roll-over problem in the program did not go away.
- The program works just fine if there are less than 4,000 characters of text - including blank lines and spaces.
Wed July 11 - general
- Present were Ron Williams, Bob Erickson, Judith Haemmerle , Joe Preston, Glenn Lea, Robert Garner.
- The following report is from Ron Williams
- 1401, there is a temporary "short/open" in/near the 01B2 gate - Ron figures the cable/paddle area. The symptom is that when you run diagnostic tests and physically rotate the gate (even just a little), the diagnostic test will do unexpected things. Normal vibration and manipulating the cabling doesn't cause a problem.
- 720 Mod V Tape, sick "A" bits. The previously reported failure to stop tape seems solved.
- On the 513 reproducing punch, Bob Erickson, Judith Haemmerle, Glenn Lea unmounted the motor generator, ...
- The third KeyPunch motor is still overheating - the output stacker just above it gets noticably warm, the motor itself gets too hot to handle. Joe Preston worked on the/a friction clutch - now adjusted to minimum, he also found a bearing not too good, ...
- Ron Williams wrote a little program to test Ed's suspected wrap-around of indexing at 4,000 characters. He started with index at 3950, indexing by 10, moving data, for or over 4000 indexing boundary - The machine seems to function correctly. Ed will re-examine his program :-|
Saturday July 14 - 2nd Saturday - Volunteer day - free food
- Present were Ron Williams, Bob Erickson, Allen Palmer, Judith Haemmerle, Tim Coslet, Ed Thelen, and Rafael Skodlar who had dropped off our team list. Mattthias Goerner (on his way to study Computer Science at Berkeley in the fall) joined us for the day. Mike Cheponis joined us about 3:00.
Allen got right to work on the 729 tape problem. This is Allen with the scope he used while fixing 729s in the old days. (A year or so ago we had to replace a transformer in it - )
- There seemed to be at least two problems involved with the tape system or interface:
First a problem that popped up and then disappeared, was that
- - card images copied from the card reader to magnetic tape
- - then read back from tape to the print buffer
(got that?) appeared on the printer to have lots of leading blanks
Just how can this happen? Allen insisted the blanks were not on the tape -
- and that he was not sending leading blanks back from the tape units analog amplifiers.
and Ron couldn't figure how he was padding leading blanks into the printer buffer.
Then the problem vanished - poof -
- Back to the original tape problem - some translation, cross coupling, ... of the A bit to/from tape.
- - we punched up some cards with numbers and letters not containing the A bit
- - examined the resulting printouts
As Allen left for the day, he said that if we left the tape drive in it's current condition, we would not have any trouble
- - The tape drive was in the turned off condition !!
- - Don't you think Allen deserves the teasing we give him?
- - Of course, he gives as good as he gets ;-))
- Matthais Goerner (our student from Germany) seems very interest in all aspects of computing. After he visited with other team members, I introduced him to the 026 keypunch. That guy is quick. He was interested in the printing function of the print head, and quickly deduced the general form of the layout of the print plate. A real "quick study" :-))
- Ron Williams introduced Matthais to our current worry - If gate 01B2 (see Wed July 11) is more than half way open, then the handle lifted vertically just 1 cm - any program (even a branch to itself) running in the 1401 will halt in an illegal state - no Storage Address Register (STAR) is selected and the memory fetch is invalid - causing a Machine Check.
Of course, one can say "don't open that gate". But of course, most of us have been bitten by "Murphy's Law" (Things will fail at the most inconvienent time!! Preferably during a VIP demo or a payroll run.) We want to get to the root of this thing before it gets to us!!
Here is Matthais Goerner going after the problem. "We" were aware that relaxing the support rods would cause the problem, but Matthais started to worry about the hinge area where the wires were routed into the gate. There is considerable stress/flexture at this hinge.
- And in the mean time !!
Bob Erickson, Judith Haemmerle, and Rafael Skodlar were reassembling the 513 reproducing punch - again. Here is Rafael doing some microsurgical prying while Bob (almost unseen) is trying to reassemble part of the frame assembly. Note the precision steel prybar ;-)) and supporting 2x4s. Serious complexity - how about working on your car's automatic transmission?
Allen split about 3:00 claiming a number of "Honey-Dews". But he wanted the record to show that he did indeed "log" a previous problem. He had found this little-bitty contact broken in some great big plug, and replaced the contact with one from some spare plug. Details added ;-))
- Mike Cheponis talked with Ed about transistor failures, types, types vs. usage, ... We found Ron Williams' logs detailing much of the above - Mike will study. Mike also proposed that SMS board testing by automated using a PC via the very common 115 kilobit/sec serial port. Mike felt that this port will be accessable for a long time - and that the interface is simple. He says all operating systems support this port in a simple manner.
- Tim Coslet talked with Ed about transistors, history, sensitivity to faults. He said that during the 1620 restoration only about 10 to 15 transistors were replaced. We wondered if the difference in our experience was the moist storage rusting the casings breaking the hermetic seal?
Tim mentioned the unpassivated junction edges of the older construction techniques. Like the alloy type used so much in our machine had a exposed ?base/emmiter/collector? junctions that could easily get contaminated.
Its been a long busy day - note the IBM wall clock. Bob Erickson, Judith Haemmerle, and Rafael are still struggling with the 513 in the back corner. Ron Williams and Tim Coslet (Seated) have been struggling with the 1401 and repairing SMS cards respectively. Mike Cheponis has come in. After some rowdy comments about putting contact juice on the contacts, we see our little theater. Matthais is explaining to Mike what little we know about the flexure problem. (They were soon trying jumpers to see if that would help.)
Wed July 18 - general
Tuesday evening, Mike Chaponis e-mailed that the 1401 would not power up. When Ron came in Wednesday, he found the circuit breaker of the -12 volt power supply at 02A5 had tripped. Ron said this has happened several times before. We guessed that it was the in-rush current tripping it because the power supply seems reliable in continuous duty. We considered placing an in-rush limiter in series with the ferro-resonant transformer, - might improve reliability. Here is a Digikey page.
- Present were Ron Williams, Bob Erickson, Allen Palmer, Joe Preston, Judith Haemmerle, Robert Garner, Ed Thelen, and special guest Van Snyder -
Van Snyder (right) drove up from Los Angeles with maybe 200 pounds of documentation for CHM, including some Univac 1108 manuals ;-)) William Harnack of Allison Akbay's Registrar group ably carted the material, with inventory, into CHM and got the forms signed
- Van Snyder also wanted to accomplish several tasks
- - debug/verify at "run the DFTs (Diagnostic Function Tests) from tape
- - there were question about machine status (what in which registers) after some tape operations
- -- (Van helps with the SIMH simulation of the 1401)
- - keypunch some small (5 card) object decks to run into the 1402 card reader to accomplish the above
- - and maybe get his hands on a working 1401 after 40 years? ;-))
Here is the ultimate "abuser"/"fixer" relationship. Van is using an 026 keypunch, and Joe is fixing an overheating 026 keypunch motor. They enjoyed each other's company.
Yes, keypunching - Here are "our" three keypunches, actually the furthest one is a loaner from Sellam. Joe Preston has just finished "fixing it. - He tested the tubes, all good, and suddenly it now works.
While the keypunching was going on, Ron Williams discovered the most sensitive place for causing the machine halts last Saturday - It was *not* at the hinge, it was at pin 11 in the furthest column from the hinge. :-| - I looked like an incomplete cold solder - wiggle the red wire a little - and the machine will halt in an illegal state. Van said that when he had visited Sindelfingen, Germany, Hintz told him that the Germans had the same problem - solved by wirewraping 3,000 power bus pins.
Probe now on pin 10 We decided that to solve the immediate problem, "we" would re-solder the defective pin. Here is Ron, on his prayer rug. making sure the job is done right this time !!!
- Van Snyder finished keypunching and tried his deck. It didn't work - so we listed the deck onto the printer to see if Van punched what he intended.
- The printer failed to print many numbers and letters, leaving spaces where the ink should have been. Analysis of the missing characters revieled that if bit 4 was on in the character, the printer would not print any character in that position. Ron had another task.
- Apparently he solved it during the afternoon.
Here is Van mounting a tape, and then running the 1401. You couldn't help notice that Van did this quickly, confidently - as though 40 years had not passed since the last time. Maybe Van never forgot how to ride a bicycle or run a 1401. - Impressive !!
- Sorry - I didn't get to take pictures or observe the IBM 513 restoration which Bob Erickson and Judith Haemmerle were working on.
Somewhere in the above we went for late lunch. It was not as sleepy as it looks - I should not have shot this looking down on eyelids ;-)) Judith Haemmerle is developing a sequence of operations for dis-assembly and re-assembly of and IBM 513. She was using WORD, but is wondering if .HTML would have been better. (If WORD converts to .HTML, all the hand drawn arrows get mis-directed. :-(((
- Van suggested we could make a PC to 026 Keypunch adapter so that we could punch out from the ROPE program. This has been suggested before, but since we had the schematics (700 KB) in hand and Joe is familiar with the internals, we went at it afresh. Joe showed me the wire harness into the punch magnets, a fresh approach?
This seemed doable and would alleviate the need for a working tape system in assembling Autocoder decks for the the 1401 - like we don't have enough unfinished projects now ;-))
- The wires seemed terminated by tabs to plug into the magnet assembly. we could install an intervening board with a plug to an added circuit and isolation diodes to suppress currents back into the wiring harness.
- Three more circuits to control card movement and possibly "multipunch" would need to be worked out.
- A return status of "cycle complete, ready for more" would seem a "good thing"
- But having to keypunch punch long complex object decks to make interesting software is not a "good thing".
- From Mike Cheponis
Thanks Ed for staying long enough for me to come over and meet Van on Wednesday [about 4:00]. I think Van would have stayed there all night if he could, but I had to leave, so we locked up at 9:15 pm.
Here's a vid of his running tape diagnostics, loaded from tape, run from tape:
- http://web.1401.org/2007-Jul/Van_Snyder_Tape_test_2007-Jul-18.mov 36,585,610 bytes
After numerous tries, it worked for a while; note that test ends in a STAR error - we've seen this before.
Another weird thing was that after running some of Van's tape programs, the "2" opcode (print) wouldn't work, nor would the "print storage" feature print anything; power-cycling the machine brought "2" back to live, as well as print storage. Van would run something else, then occasionally the "2" opcode wouldn't work, but it came back after power-cycle (we only power-cycled twice to be sure there was cause and effect.). We didn't try to track this down, or to figure out which of Van's programs tickled this, because Van was working hard on the tape bug. One important detail: the machine just stopped at the "2" opcode - just like it does on a "1" opcode when it's waiting for cards (normal, so put in cards) - but for printing, it seemed as if some sort of "printer ready" bit was not getting back to the main CPU or something like that.
We tried for a while reading back a load-mode record from tape, and only got two characters: an "A" bit in the first character, and a Group Mark in the 2nd; no other characters, and these two were not correct. We tried this several times.
Then I suggest trying low density, and that worked better. The video, above, and most of the tests, were in low density (the exact density of the 729-V drive is determined by a switch on the 1401's diagnostic panel - we had it in the most counterclockwise setting of 556 bpi. It would be interesting trying these again at 200 bpi.)
From Bob Feretich - 7/19/2007
- The high density (800 bpi) oscillator card was removed from the 1401 TAU and placed in the "Bad Card" box to be repaired several months ago. Since then we have been running in 556/200 bpi modes. Most likely, its been repaired and is ready to be reinserted, but I don't know for sure. I had forgotten about it until I read this e-mail.
Van wrote a couple of pages in the log describing what he observed from all his various tests.
I suggested that he come up here more often - 'cause he was sorrta like a guy who had been in the desert for long time and finally got a sip of water...
Wed July 25 - general
- Present were Ron Williams, Bob Erickson, Joe Preston, Judith Haemmerle and Robert Garner.
- This report is from Ron Williams
- Much of the morning was spent with power off and Robert Garner videotaping Bob Erickson talking about the 077 Collator.
- Much of the afternoon was spent helping Allison Akbay unpack and identify objects trucked in from Portland, OR, from the Werner house.
- Our sole "working" 729 tape drive seems quite unreliable and full of quirks.
- - Sometimes you have to roll the window up and down several times to get the tape drive "Ready"
- - The reel release button takes a while to take effect. Somebody will depress it and nothing releases. Then somebody else says "let me try it" and about then the thing works. Van Snyder had that happen to him also.
Received from Van Snyder, Monday July 23, 2007 - DFT 5310, ... -
On Thu, 2007-07-19 at 23:48 -0700, Mike Cheponis wrote: > > Do you recall which diag(s) was(were) running? > > Van would know best; 5310, 5320, and 5330 ? 5300 and 5310 are the programs that write the other diagnostic programs and their detail cards to tape. I had put 3100, 3110 and 3130 behind 5300 and 5310, so the tape had 5310, 3100, 3110 and 3130 on it. I just picked 3100, 3110 and 3130 at random because they were handy and didn't test the card reader or tapes. 5300 writes 5310 and the other programs and their detail records on tape. 5310 is a loader that is the first record on the tape. It decides which programs to run. If switch F is off, it runs all of the programs whose ID in 73-76 of the first card (the one with A in column 80) are different from 1273-1276 (S73-S76). With switch F on, it runs only the program whose ID matches. I keypunched 5300 and 5310 from the listings in volume 2 of the diagnostic notebooks. I left these, wrapped in a scrap listing, in the diagnostics box behind the power converter. I double- and triple- checked them, but it wouldn't hurt to check them again. I also keypunched the one-card program listed in the 5310 write-up that loads 26-80 into 1226-1280. Load this program (using start-reset, load) when the tape loader stops with 1369 in I-star. It copies 26-80 into 1226-1280 and then branches to 1369. This is handy for setting stuff, including the ID of the program (not) to be run. Many of the diagnostics want parameters in the 1250-1280 area. Look in the book for each one. In particular, essentially all of them want "1" at 1252 (S52) to print the heading card that identifies the test. I tried to get the diagnostics on the tape to print the heading by putting 1 in 1252, and to print correct results by turning on switch C, but didn't get any output. I should have tried things out by running from decks, too. Anyway, I ran out of time when Mike had to leave for the airport. I also keypunched an 8k dump program from Germany, which I left on the wheeled cart between the 1401 and the power converter, atop a tray of other programs. It's also wrapped in a scrap listing. Behind it are a blank card, and two cards that I translated from German to English. If you leave them in the deck when you run it, it will report that switch A is off no matter whether if's on. I haven't studied it enough to know how easily it could be converted to dump 16k. I also have another dump program that I didn't keypunch. I don't know what size memory it dumps. I've attached my disassemblies of 5300 and 5310. I put a bug in the ears of Ed and Joe: Connect a PC serial port to the punch mechanism in a keypunch. I mentioned this to Mike, who as it turns out was already planning such a thing with his 029. It wouldn't be anywhere near as fast as using a connection between PC and the TAU or SIO and punching decks using the 1402, but it would be a lot faster (and more accurate) than punching by hand.
From Karl Bleher (Sindelfingen, Germany) July 24, 2007 - backplane power cracks -
Hello Robert, Subject: Your report of Wednesday 11.07. errors when touch the gate 01B2. Close to the end of our system debug of our 1401 system in 1992, we have been irritated by sporadically errors if we touch the TAU gate. The error could be forced by a touch to the gate and to the voltage and ground pins in the gate. So I take a closer look to the power rails The result was shocking. There has been cracks between the powerpins on the SMS card sockets and solderpoints at the voltage and ground rails, which could be seen by a good magnifyingglass. How to fix it ? Resolder was not possible, because of the wiring passing by. The only reasonable way seems to be wire wrap. I put wirewrap chains on top of the powerrails on all TAU gate. After this timeconsuming procedure was done, the system operats stable, even by manipulate the gate. This has been done by colleagues maintaining the system to nearly all gates. Good luck ! Karl.
From Allison Akbay (CHM Registrar) - to Frank King - July 25, 2007 - Werner, Oregon shipment -
Ron Williams, Bob Ericson, Joe Preston, Judith Haemmerle and I went through the Oregon shipment today. I needed help identifying everything so that I can send the tax receipt to the donor and I wanted to make sure that members of the 1401 team knew what was in the shipment. There were five boxes of materials that we inventoried which have been added to the attached excel spreadsheet inventory. [html version]
The 1401 team members requested that the following materials be transferred to be used in restorations:
- All small plug boards
- 024 keypunch base
- Card weights (2)
- Punch card storage cabinets (2) they currently contain cards which may or may not be useful to the 1401 team
- Punch card sorting rack
- IBM 519 Electric Document Originating Machine
- IBM 085 collator
- IBM 077 Collator
The team requests that the following documents be made available to the team as soon as possible:
- IBM 519 Electric Document Originating Machine wiring diagrams (located inside machine)
- Manual IBM number A24-1010-1 (title page missing, located in box 2)
- IBM 514 manual and wiring diagrams (located in Box 3)
- IBM 077 manual (located in Box 3)
In addition, when passing the machines given to the Museum by the Museum of American Heritage the team members mentioned they would also like to know the feasibility of having the IBM 403 from that collection transferred for use in restorations.
Ron, Bob, Joe, and Judith thank you for your help and please let me know if any of the above is incorrect. If the list of items you would like transferred to restorations is correct please use the forms provided by Alex and Dag to officially request the transfer. This might seem buearocratic but using the form will make sure that everyone who needs to know is told in writing so that a decision can be made by the curatorial staff and the machine official transferred out of the permanent collection and into the study collection.
Thank you again for your help.
Sat July 28 - 4th Sat
- Present were Ron Williams, Bob Erickson, Judith Haemmerle, Tim Coselt and Ed Thelen. Mike Chaponis came in about 3:00.
- When we came in Ron Williams pointed out that the DC breaker of the -12 volt supply in the 1401 had tripped again. We reset it and the 1401 powered up just fine. - a lingering problem -
- We had some guests who key punched their names, then we had trouble reading the Big Print deck into the 1402. It seemed that the deck was of a poorer quality of cards (felt softer and less stiff than the usual IBM cards). Regular decks fed through the 1402 card reader just fine. Guests went away.
- We tried to reproduce the Big Print deck using the 1402 reader/punch. Good news/bad news - About 95 % of the cards reproduced correctly. Bad news - about 5% of the cards had missing or extra punches. It seems that the 1401 card reader is working well, that seems to indicate a 1402 card punch or electronics problem. (Even Ron Williams says this is not a software problem ;-))
- While Ron and Ed were struggling with the bad card stock and the bad reproduction of the 1402 punch, Tim grumbled about burning a pad off a board due to an overheating soldering "iron". Ron had noticed that the Weller soldering thing we have acted oddly while he soldered the backplane pins Wednesday the 18th (above). The thing was very erratic again -
- WARNING, The unmarked WELLER soldering iron does not regulate properly, overheats.Tim went to his car and brought in his - but Tim needs his Weller home!
- We need another proper soldering iron.
Jim Somers brought mail for Judith Haemmerle. This was 513 reproducing punch documentation, including wiring diagrams. Judith had located someone in IBM archives who remembered that she had seen 513 documentation in a patent search question, and was kind enough to dig it out and send it to Judith. Judith has now made copies of this manual, including the wiring diagram extended pages and will return the manual to IBM. (We won't have to depend upon Bob's memory of 50 years ago :-))
A few weeks ago, Bob Erickson removed the Motor Generator from the 513 in order to get at some relays behind the MG set. Today, I decided to play, and removed the bearing end caps to check the lubrication. The grease was a little wax-like but Bob Erickson said that it looks that way 50 years ago - looking good. We squeezed in some more IBM grease that Bob had, re-checked the brushes and decided to run the Motor Generator.
How much current at what voltage should this machine put out? Look at the name plate ratings. :-))
- This machine weighs over 100 pounds and must have cost a pretty penny. All it puts out is 4.8 amps at 40 volts, about the same power as the power supply in your PC which weighs maybe 10 pounds costs maybe $20, and fits on your hand. That is visible progress :-))
OK, play time :-)) Here is Tim Coslet in the midst of it all. We powered up the motor, worrying that the starting torque might jump the machine off the stand (I was bracing it). Peaceful start, no jump at all :-)) Here is Tim adjusting the field winding series resistance to get 40 volts, and applying about 1 amp of load.
- Mike Chaponis came in - full of ideas as ever. He has been vigorously proposing we use a proprietary product on the circuit card contacts of the 1401. There has been a heated debate, should the rest of us have to prove the product dangerous or useless or should Mike have to prove product utility. Robert Garner has been e-mailing IBM researchers about the details of the gold plating - is it onto copper or nickel, porosity, archival concerns etc.
- So today, Mike brought in a board that looked like from a DEC Q-BUS, and wanted to compare 95% isopropyl alcohol vs. his pet product.
Here is Mike's DEC Q-BUS card, from e-bay, looking rather grungy. Squirting on plenty of isopropyl alcohol on the right hand side and rubbing vigorously.
Well, OK, it looks a little cleaner Here is the product Mike is touting Applied to the left side, and a rub-a-dub-a-rub-a And some discoloration on the paper from the board.
But the judges, Judith and Ed (Ron and Bob declined to get involved) declared the cleaning contest a tie.
- Mike plans to continue removing dust from more gates in the 1401, but says that he is in is no hurry to apply any chemicals.
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