elog2004

The ICT 1301 Resurrection project

The 2003/2004 Repair Diaries
The visit diaries are now entered here, in reverse chronological order, so the latest news is on top. ( more updates as and when we visit. Do check back for pictures, updates and news on this project )

Entries from August 2004 on are here

Entries up to end July 2004

22nd Episode:-18/8/04
First job of the day was to solder up the replacment mains connector for our damaged scope, We have been using an analog scope, during the period that this storeage scope has been down and I now miss its facilities very much. We are trying to work around the drum logic and trying to see a single pulse, one micro second long every 11.5 milli seconds is a challenge to an analog scope I assure you, but I hope the repairs will be completed soon.
Clock setup time again, this time some success and a stable datum pulse was extracted for each drum revolution, without this the various counters which time the data off the drum cannot syncronise to the drum and data would never be decoded properly. a trip along the digit counter showed a stuck two bit in 11A22 ( T1 package changed ) then on to the word counter. This was stuck and not counting at all, it was set to all ones and no clocking was taking place.
This counter is driven by two clock sources, the main one drives the counter once per digit the second one only sets the initial state of the counter, and it was the initial state that was not bieng set. Some time spent here scoping around as after changing the first clock gate in 11B19, also did gate in 11A1, did not change fault, as I had the same condition. It was not until I jumpered both sources together and saw the word counter start, that I realised the replacement clock gate was also not working, so a second package in 11B19 did eventually give us a working word counter. And a bonus ! We now have an alarm tone on the console speaker. We have not had an alarm tone that I can rememeber for a long while, so on we ploughed, the decade counter was now running as well as the word counter so hopefully we now have the ability to try to fault find the rest of the logic.

Some observations at this point:- the drum count signal does clear, after switch on, slip pulse ( clocking error ) does not, so it is back into the modified area of the drum. First test was to just listen to the alarm tone and trip the drum drive motor, the alarm signal followed the decreasing speed of the drum for an impressive period of time. This was a simple test but it proved the modified clock was working. Now the problem was to find which signal was giving SLIP PULSES ( or drum clocking errors ) . Sources are 11F19 ( pin 24 ) Isolated, 11F23 ( pin 24 ) also isolated, no more SLIP PULSES. This confirms that the drum clocking is still not perfect.

So into the clock checking logic and changed 11F18 and 11G8, this is part of the Q time counter and the waveforms around here dont look good, whilst changing the above boards it was found that the bistable in 11G8 was very selective as to what boards would or would not run in this position, at one point the precious alarm signal also stopped, so I know we are in the right area.

The day ended with a decision that we have too many boards on rubbers ( again ) and the next session must start with a tidy up and, checkinf that the micro orders work for other functions before we risk fault finding the rest of the drum transfer logic .
21st Episode:-4/8/2004
Some dropout and gaining on punching, we have put an earth to the punch frame, from the Zero Volt braid, and will have to test the reliablility at a future date.

A brief investigation into the MOVE or 45 Command counting too many words, stopped when the problem vanished during investigation, this was around the decade counter logic, also used by the Drum logic. So having been lead here now it is time to enter the complexity of the DRUM Clock logic once more !

Most of this visit, spent chasing our tails, around bay 11, 12 and 6. ( the trip to bay 6, was to change the ( first micro order on ) bistable in 3B16) No positive result from our efforts other than, we have eliminated the folllwing ! The clock, and Datum track itself ! ( have used spares ! ) and changed the most relevent boards, 11E3 drum clock . The primary problem is that the counter which splits the incoming timing track into quater pulses Q1 thru Q4, has been modified, ( capacitors Soldered to the G1 gate package in 11G11 ) along with the clock source to the counter bieng modified, Also the timing generator has been replaced with a modern phase locked loop chip! ( this at least is still working ) The whole essembly has obviously all worked at one time, but is refusing to work again at present.

No Drum clock and Datum decoding = No drum = No Initial orders !

Finished the day with the discovery that we are getting far too many Datum Pulses Generated, ( we are only meant to get one per revolution of the drum ), work will continue on the next visit !
But we are working with an elderly analog test scope and it is not good enough to resolve some of the single pulses we are searching for on this problem. A feature of this problem is that we lack a stopped status alarm tone on the speaker, when the clock system is switched to the drum ( normal mode of operation ). This should be very relevent, but its significance keeps escaping me, all will be revealed when the problem is finally resolved.
20th Episode:-
Various problems with the card punch again, Cam's cleaned and very basic timing checked, many relay points, now a lot cleaner. The Punch tries to punch most data now, we may have a driver in Col 44 which will need to be replaced, however the capacitor's on the board, are not looking too healthy, so it may be a change components job to resolve.

Using some software Roger wrote we found the 380045 ( Check brush reading ) failed, found G3 package in 1B19 ( pin 4 ) U/S, replaced and now Ok !

19th Episode:-
Work after the open day restarted with a whole day being spent on the Card Punch, the problem was finally resolved to the coil of relay seven ( yes it had gone open circuit ), but we did have the right part.
The Diagram for the Punch and the Wiring in the Punch are very different, Relay 10 does not even exist, any more and wiring around relay 7 is very different
Further work went into ensuring the hold path for the ready circuit was clean and functional ! ( we also Lost our precious osciloscope at the end of this session ) a nasty smell of burning filling the machine room. Or should I say an expensive smell of burning ?
18th Episode:-
Two whole visit sessions were put to tidying the console end of the machine for the visits, along with limited work on the Card Punch !
Special visitor today = Stuart Fyfe, one of the original owners of Flossie ( Great to see him standing at the console once again ) he also lent us some dispaly material for the open day, " Nice one Stuart ! "
"Notes from the 2004 Open day "

17th Episode:-
Work continues on the Mag tape drives and now we have two ( working ) Transports

Both Deck B and D now work, and communicate with the Tape control unit.

With the two decks up and running, the place now starts to sound like a computer room of the 1960's ( Lots of noise ! ). To add to the Cacphony, we started to find out just what of the peripheral devices would and would not run.
But first, after an experience Roger had with the card reader, we checked the direction of the three phase motor's. Sure enough we had to reverse two phases at the main connection, I wonder what else will now start to run correctly, now this is resolved ?

So what now Work's?

The card reader suffered a nasty stripped belt when it was run with the phases reversed, that coupled with many of its rubber and neoprene parts, now decomposing the Card Reader is going to be ( How do I put it ? ) A Challenge !

The Line Printer looks as if it might run Ok ! But there is a lot of work in checking out its main's wiring and a long time will be spent setting up 120 print hammers to work, as well as muttering a lot as we set up the paper throw mechanism. ( yes SPRAG's ) for the initiated, are a pain, but we will have to visit that pain soon !

So attention turned to the Card Punch!

We started by removing the drive belt, and we cautiously turned the mechanism over by hand, we tried to turn it on ! Nothing ! Absolutely Nothing ! So all covers off ! First a duff fuse in one of the 20volt lines. Then proding and metering around the main's contactors, and then the relays ! We were rewarded with a loud CLUNK ! from the contactor !
Also the drive motor turned the right way,the drive belt was refitted, and we were again rewarded with the sound of the machine doing a single card cycle. Some time was then spent clearing our first card wreak, from the feed path, and after that the punch settled down to its new life of work.

For the uninitiated, this was a big bit of luck. The punch gearbox is quite a complex piece of work, and owe's its ancestory to the original design of the Hollerith Card Punch, Card Reproducer ( Punched Card Copying Machine ) . That design in turn, is now over 60 years old as I remember working on Black painted machines with were marked " Lease Lend " from the Second World War years, these had the same essentail design !

Some in depth checking of oil levels in the gearbox followed, and now we have a working Card Punch.
Now Eleveated by our good fortune, We started to Discuss SHOWING FLOSSIE OFF !

So We may be off of our tiny mind's, but Flossie will be open for Public View ( Working or Not ) on Sunday the 11th Of July 2004. Where the history of this machine will be explained to any visitor's and access will be granted to view the Consul end of the machine. No promises, BUT if Flossie decides she will run's on the day that will be a bonus !

The event which flossie will be viewable at is the " Darling Bud's of May Classic Car Rally " at:-

Buss Farm Bethersden Kent, on the 11th July 2004

Just follow the signs on the day, and dont forget the * Darling Buds Classic Car Show Buss Farm Bethersden Kent * is an Event not too be missed Anyway, with so many dedicated car enthusiast's displaying with pride thier work on Car's, which in some cases are older than Flossie's 40 Plus year's.

16th Episode:-

Investigation into access to magnetic tape transports:-
Of the four Ampex Type 3 decks we have connected to flossie the attempts to power them up gave us the
following results:

Deck A = Tight / Locked lower servo motor ( investiage later )

Deck B = Loaded tape runs forwrds / reverse and responds to read, rewind and unload commands. ( Good Deck this one )

Deck C = Loads up tape, responds to rewind, and unload commands. No response to any other commands and just goes busy.

Deck D = Loads tape, has a servo problem with the upper reel Drive and needs the forwrds Pinch roller assy adjusted.
tried to resolve the servo problem on the supply reel, but had to postpone till next visit

So using the best deck from above, we investiagted just what we could and could not do with the tape control logic Attempts to read do not transfer any intelligent data into the machine but the transfers do finish and we tried to run a simple loop, which included testing the deck ready indictor, doing a read order, and repeating the loop. This ran perfectly provided we ran it one instruction at a time, in manual mode. However any attemts to run this in auto mode, gave us corruption of the program code. After much head scratching we found that we had isolated the Control register shift timers whilst fault finding last year, at 6E3 Pin 13. Restoring this gave us data input into store, blocks of about 120 words could be read in but the program corruption problem continued.

This problem has been traced to bay 22, where 22B23 pin 22 there is another level from the 1900 series standard interface signal comes in, isolating this gave us a reliable program loop, so we closed the day with a successful run of the following little loop !

With our one working deck allocated to deck address 3

000 = 834001 004000 ... / wait for Deck 3 Ready
001 = 724002 004000 ... / wait for read unit ready
002 = 390023 000400 ... / read a block into store at address 400
003 = 834001 004003 ... / wait for Deck 3 ready
004 = 724005 004003 ... / wait for read unit ready
005 = 390053 660100 ... / Rewind deck 3 and increment count
006 = 370100 004000 ... / display count in B Reg and loop back.

This loop reads a block, rewinds the tape and displays a count of how many times it has done the loop. We held our breath until the count had reached over 50 and then decided we had actually fixed the problem.

Next visit is with feeler gauges and allan keys to set up the rest of the Tape Decks. I felt very bouyed up as most of the tape control unit was working. But we still need to actually read the data from tape some time ! So we are getting ready for a battle with the DTU !

15th Episode:-12/5/2004
Continued work on store units:-
Barn Door 3 lots of differing errors
Barn Door 4 Acting dead.
Much work on this store including changing a G1 unit in 10E17 ( decoding unit ) until we finally located an addressing problem where decode 80/180 and 90/190 were both comeing up together. This seems to be within the structure of the door, and much time was spent tracing wiring on the printed circuit strip panels which run the length of the lower part of the core planes. Ended this session with a rather blank feeling as the progress had been zero. We still have Barn Doors 3 and 4 to fix.
Lots of boards are on temorary connectors in this barn door. However these two bard door's have never worked since the start of the project, so we have only to fix them once and hopefully they will stay fixed !
14th Episode:-
More work on store units and lots of data bits dropping out:-
Digit 7 Bit 1 + Digit 5 Bit 8 + Digit 7 Bit 2 all failing,
so much sorting of duff A7,s ( store read/write anps ) and we had reliable access to some store, with a duff -6.3 volt Fuse ( 20 amp ) blown on the way !
We are now down to a single duff word in barn door 2 ( much time spent wiring in the " SPARE " core word on the Store Plane ) after many tries we re-read the manual and remembered to wire in the ground connection to the spare address line, we now have a working second store unit. We can run a small loop of move ( 45 ) orders and the store does not give parity failures.
The day closed with us trying to run "Ghost" but we may have a problem with Function 69 ( multiply ) so ghost just produces a boring single note in the speaker. I bet this is micro orders again, but only time will tell !
13th Episode:-
Programed indicator tidy up!
We have had problems with two of the programmed indicators since this project started. Over a coffee before we started, it was decided that we would indulge ourselves and just fix these indicators, before we did any more work.
PI 11 turned out to be 7E9 binary u/s = replaced,
and PI 12 was the 7E10 binary , now all ok ! And a big boost to our confidence.
There are still problems with access to the store units, work around the IAS timing generator resulted in changing the Binary in 10E8 and Invertor in 10E9 these gave us correct IAS timing and timing signals W1 and W2 are now correct, Still no access to any store. Checked all voltages and found 18 volts unit fuse blown.
We can bow run a loop in the first barn door, Much jubilaton followed! we had access to Bard doors 1, 2 and 5 but word 518 in Barn door 2 was a solid fault.
12th Episode:-
The First Power up 2004 ( no smoke ! No big bangs ) But the machine is stuck in micro orders !
30 mins later, during which we checked all fans and power supplies. The system started to run, but with problems. Found Binary in 3B17 duff ( not adding one to Control register ) Now OK but still no access to store at all. Traced to 3E17 Pin 3 duff, also A1 package in 6F7 and G3 in 6F8, Now able to get some instructions into the control registers. Well as a start in 2004 it could have been worse, but we will have to get flossie back to where we left her last year.
Most of the things we fixed last year do seem to be working, so not a bad 1st day in 2004.
Start of work in 2004

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