Monday, May 30, 2016

1442 reads fine, cornering still not right; 1053 problems mitigated; starting on memory expansion

1053 CONSOLE PRINTER RESTORATION

My challenges with the 1053 related to a few areas. First, the space button sometimes caused a tab. Second, the carrier return sometimes jammed past the left margin. Third, sometimes the tab movement didn't unlatch where it stopped. Fourth, line feed sometimes stuck on for a few cycles.

The carrier return problem was a real challenge. No settings or advice from the maintenance and theory of operations manuals gave a clue as to why this happened and how to stop it. Further, the illustrated parts catalog and the diagrams in the maintenance manual did not match the part on the carrier which engages with the margin, so I couldn't see how it should appear.

The resolution was to remove the part on the carrier and reason out how it would have to perform in order to work properly. That finally led me to realize that a slanted bar on the part was bent out of position. When I restored the bar to its reasonable position, the latch which allowed the carrier to pop over the left margin will not do an absolute stop.

Testing proved that the return will now work right, without wedging behind the left margin. I worked on the tab and space issues and determined that these were residual lubricant issues which will work out of the mechanism with more use.

Specifically, the tab levers on the carrier are meant to snap all the way back when the carrier reaches a tab stop, but the old oil keeps the part from pivoting smartly in some cases. When it doesn't pivot all the way, it remains with the tab movement unlocked, so even the use of the space button will trigger a tab movement. Once the tab movement locks, as it does most times, space causes just a single space movement of the carrier.

Line feed is similarly symptomatic of residual old lubricants still being moved out of place by new oil. The cure for all of these is use - more tabs, spaces, returns, line feeds and backspaces will eventually yield a correctly operating machine, with symptom occurrence rates asymptotically decreasing to zero over time.

I have to string the ribbon color shift tape onto the machine, repair one lever that selects single versus double spacing, and put the covers back on the typewriter. Once that is done, it can be lowered into place and will be considered finished. The color shift tape will take a bit of adjustment to get right, of course, and the process of replacing the covers is awkward to say the least.

1442 CARD READER/PUNCH RESTORATION

I fired up the 1130 system and tried a Program Load of a boot card through the 1442 card reader. Success would be seeing all eighty columns transferred correctly and no error checks on the reader. I met that goal - I can boot various cards without error.

Beyond the ability to read a card without error, the cornering station and stacker adjustments need to be completed so that cards will reliably move all the way through the machine and out into a stacker. This still needs finessing. A bit more than half the time, the card is sent to the stackers, but otherwise it hangs up in the cornering station causing a check condition.

I also found that the mechanism to select stackers is a bit dodgy, so that sporadically I will get a card wedging up at the exit rollers on the far stacker. This damages the card as well as causing a check stop. I suspect that the cards are entering the stacker area on a slant, which cocks them various amounts. Rotated too much and the card edge will block on one of the two rollers and fold over.

This all comes down to adjustments of the cornering station and stacker. When that is right, I expect everything on the reader to be right (ignoring the broken punch unit).

pushrod wedged and cracking off ceramic on previously intact wheel
EXPANSION MEMORY FOR 1130 - EMM BOARD TO INCREASE TO 32K WORDS

I began more detailed design work and determined that my connections to the board are via a pair of old-style .125" spacing edge connectors, double sided, 40 per side or 80 per connector. It is a holiday today but I can pick up the connectors tomorrow and start wiring them up for signal, control and power. The goal will be to use an FPGA to exercise and test the memory, also to prove out operation they way I intend it to work.

Sunday, May 29, 2016

Almost there with cornering station on 1442 reader

1442 CARD READER/PUNCH RESTORATION

I put the broken punch unit back in place, a tedious and careful process due in large part to the wonky pushrods that will fall out if they are even looked at too sternly, clearing several pushrods and lots of other gears, belts and protuberances. With that done, I could hook it up and adjust the magnet assembly so that the punches are held from pushing down through any card in the punch station.

The punch unit serves its secondary role of holding and releasing cards on their way between the read station and the stackers, but is unable to punch holes and advance cards due to the missing row 9 punch and the damaged drive wheel. My goal at this time is to get the card reader working properly, ignoring the punch functionality entirely until some later time when I choose to take on a restoration.

I raised the plastic cover on the cornering station and now cards will reliably eject, but I have to tweak the two pushing arms that give the card its initial shove. They don't retract far enough to let the card drop in front of them always, so that the card sometimes sits on top of them. This might be due to the raising of the cover, so I will have to play with several adjustments in order that the cards begin to corner every time.

The results are good enough right now to consider the next step - attempting to read a card. I will set up tomorrow to try this, using both the Program Load (boot) mode and the card reader functional test program. Reading properly without a check will show that I have enough of the hardened old lubricant out of the clutches and bearings to eliminate the drag that these caused for reading. Too much drag, the card moves too slowly and the error checking circuits spot it and raise the alarm.



Saturday, May 28, 2016

1442 Card Reader/Punch is quite broken in the punch mechanism, but have hope for the reader side

1442 CARD READER/PUNCH RESTORATION

I am quite hampered by the fact that the illustrated parts catalog for the 1442 does NOT show the type of punch on my machine, the part I am trying to replace/repair. There are three types of punch units, A, B and C and in the C there are individually replaceable and group replaceable punches. I have a type C with individual punches. The catalog shows punch type C but the wrong type of punches.

It appears as I attempted to fit the punch that the part I have is broken off, with the remainder of the punch down in the holder where I can't see it. The reasons I assume this:

  1. The punch, of which this piece is a partial example, extends down through the body and several guide bushings so that it can extend out into the card throat to push through the card stock. The part I have is not long enough by far
  2. The punches go down through a 'punch stop comb' under which there is some kind of spring to push the punch back up after the punching pressure is released. The parts catalog for the incorrect punch types shows this as a helical spring held down between the body and the punch stop comb. It would have to make contact somewhere on the punch itself to push it up, yet there is nothing on the part I have where the spring might make contact. 
I may be able to extract the broken off part, assuming it is in the body and that the helical spring has not gotten free and fallen out where I can't find it. However, that is a much more major disassembly than any in the maintenance manuals and likely will involve repair or creation of a replacement punch part, with quite a bit of delay.

Since I have a limited time to get the 1442 operational for use at VCF West when I am demonstrating the 1130, I have decided to forgo any punching. I will reassemble the punch, sans the row 9 punch part, and put it back into the 1442. That way, I can get card transport and reading operations working properly. At some later point I will take on the task of attempting a punch repair.

This afternoon, I reassembled the punch and began to install it into the 1442 chassis. All was going well until one of the pushrods got itself wedged very strangley, wouldn't come loose, then put enough pressure to crack the other ceramic wheel on the axle where I had just repaired one side. Yes, you read that right. The second ceramic wheel now has an arc cracked off about the same size as the original defect I spent weeks repairing.

Fortunately, the ceramic wheel only turns by means of the intermittent drive unit, which is only activated during punch operations. The punch has one broken/missing row punch and a broken drive wheel, so doubly inoperative. I have to say that I have developed an animus towards this particular mechanism which may delay any attempt to repair the punch for a loooong time.

At least I can get back to testing and repairing the card reader function of the 1442, deliberately leaving the punch side inoperative. I might even look at ways to block the logic from attempting a punch at all, to avoid having the mechanism move the wheels or drive the punches.

Friday, May 27, 2016

Jam removed from punch, discovered one of 12 punches had fallen out

1053 CONSOLE PRINTER RESTORATION

The 1053 has three buttons across the front, which invoke space, tab and carrier return, in addition to the solenoids which command these three functions as well as line feed and backspace operations.

Two of the buttons trigger tab, although one of them should only be invoking a single space operation. I also have some remaining issues with the return skipping over the left margin stop and jamming. This may be more gunk from the residual bad lubricants used by IBM years ago, which do not age gracefully.

1442 CARD READER/PUNCH RESTORATION

It is definitely the punch for row 0 that is stuck down in the die. I suspect that I will have to remove the funnel for the chips that fall, then remove the punch die in order to free this up. The goal will be to install it properly so that the punches slide smoothly in and out as they go down and up.

After removing the funnel and the bottom plate, I still had a serious blockage. I decided I had to remove the punch unit from the 1442 chassis in order to work on this. Second time around, removal was quicker.

Punch removed from 1442 chassis once again
Looking into the throat made it clear that I did have a major card jam, not just a stuck punch. It took me a couple of hours of careful prying and sawing and maneuvering with a keypunch card saw before I got the jam cleared. At that point, I noticed the reason that my original symptom was lacing with rows 4 to 8  but not row 9. The punch for row 9 is not descending.

Jammed card visible in throat above wheel
I suspect that this is the funny U shaped part I found. I am going to have to disassemble this much further in order to get to the punch and repair it. Worst case, I may have to manufacture a replacement part if some part of the punch has snapped off. The parts catalog and repair manual pictures are useless to determine what this U piece is or exactly what the punch parts look like.

Using the instructions for replacing an individual punch, I began removing parts from the punch unit to get to the row 9 punch. As soon as the last parts come off and gave me a direct view of the punches, I confirmed that the U piece is indeed a punch.

Punches visible, leftmost (row 9) is missing
The punch which fell out
The U piece, with its two legs much longer than the crosspiece, is how the machine punches holes. The two prongs cut the hole in the punched card, sliding down into the die. A spring pushes them up out of the die, but I don't yet see the springs to know how they attach.

The cross piece on top is what the interposer fits against - the interposer has a ledge that allows the crosspiece to sit against it and be pushed down as the interposer is pushed down. Above the interposers is a wide bar, the bail bar, which is spring loaded upward and forced down by the main punch cam roller when it is time to punch holes.

I think I have an intact punch and only need to fit it back into the die, but the angle is (of course) quite awkward for maneuvering a small piece into place. I chose to wait for another day when I am fresh before attempting the insertion of the row 9 punch, after which I can carefully reassemble the punch unit.

Once I am sure that all twelve punches descend properly, the punch can go back into the 1442 chassis. One of the dis-assembly steps before replacing an individual punch is to remove the solenoid assembly, so I need to readjust those once again.

RESTORING CALCOMP 565 AS IBM 1627 PLOTTER

I received more information on how a fellow enthusiast recreated the pen and solenoid assembly that was missing from his Calcomp plotter and which I am also missing. These show much more detail on how to machine the various parts. I am hopeful that this is enough to proceed. In addition, he has videos of all the steps which are available if I need them to resolve any questions during the process of manufacturing.

Still no word from the metalworker so time to find a plan B for building a replica of the bent drum.


Thursday, May 26, 2016

Adjusted punch of 1442, lacing disappeared, now working on cornering station ejection

1442 CARD READER/PUNCH RESTORATION

Did some initial diagnostic work to zoom in on the problem of my 1442 punch allowing the punches for rows 4 to 8 to be activated on every rotation of the motor - thus randomly lacing cards passing through the punch station during an NPRO.

I tried with my SAC Interface box powered down - same results. This means it is not my logic injecting bits into the machine. I checked the secureness of the main signals cable where it attaches to the 1131 - looked fine. I did try to feel for a magnetic field during operation, using a screwdriver near the punch solenoids, but no luck with that.

I looked over the logic diagrams for the SLT cards inside the 1442, to see if there was a common card for just those five rows. That did not pan out. Next, I looked at my ALDs for the adapter logic inside the 1131, to see if there is a common card that might explain this symptom. Nothing fit the symptoms there either.

I moved on to the mechanical adjustments and checks. I soon came to realize that the magnet assembly mounting screws were loose and the assembly was skewed away from the bottom row punches. I tweaked this and tightened it down so that no punches were activated on NPRO cycles. I may have to play a bit with it to ensure that all desired holes do get punched, but for now it is good.

Next up, I have to face the puzzling symptoms - I only saw rows 4 to 8 punch but from the top I can see that the interposer is active for row 9 as well, but the cards didn't have that column punched. Right now, I have a small wedge of card that tore off in the punch station area which I have to clear before I can go back to my tests and adjustments, but I am moving forward nicely.

It appears that the wedge is not a piece of card, but a stuck punch - perhaps the row 0 - with the interposers and remaining mechanisms unactivated it is stuck down. I will have to figure out how to deal with this, hopefully without having to remove the punch unit and disassemble it.

CORE MEMORY EXPANSION TO 32K WORDS

I received my EMM 32K x 18bit core memory module today and immediately ordered the +15V, -15V and +5V power supplies needed to use it. I will set up a quickie FPGA design to drive and test the core memory in various ways - timing, bit retention, holding various patterns. In the interim I can plan out the way I would interface to this core from the 1130, design circuits, layout the implementation and the rest of what I need to make this work. 

Wednesday, May 25, 2016

Investigating possible causes of 1442 punch lacing during NPRO

1442 CARD READER/PUNCH RESTORATION

The punch unit has three cams rotating in synchronization, moving mechanical parts. There is a main or punch cam, an interposer restoring cam, and a punch restoring cam. In addition, twelve solenoids will either pull an interposer back out of the punch path or let it pop out by spring pressure. The solenoid has a constant hold current which pulls the interposer back and another winding that neutralizes the pull of the hold current when an interposer is to be released into the punch path.

The punch cam pushes down on 12 spring loaded rods, one per row of the card. If a spring loaded interposer has moved out into the path of that downward rod, then the rod pushes the interposer down which pushes on the spring loaded punch itself. This pushes the punch down through the card and into a punch-shaped die below.

The punch restoring cam will push all the punches back up, pulling them out of the die and through the card to reach their original raised position. Thus, the punch restoring cam is timed to push up after the punch cam itself has finished pushing down. The final cam is the interposer restoring cam which pulls the interposer back against its spring load, so that the hold current in its solenoid can keep it retracted. Thus it stays until it is next selected by the neutralizing counterwound current.

This means that when power is off to the 1442, all twelve interposers are pushed into the path of the punch rods and all twelve punches will push down through a card and into the dies. When power is on, all twelve should have only hold current applied and thus all twelve interposers are kept out of the punch path. No punch should descend with hold current on.

The only way a punch should descend when power is on is when the counterwound coil current is also applied, allowing interposers to spring out into the punch path.  Since the punch unit and its three cams are constantly turning whenever the 1442 motor is turned on, it is only by way of the hold coil current and absence of counterwound coil current that the punches do not descend.

My first power up test had punches for rows 4 through 8 descending on every rotation of the punch cam, which should be caused by one of three cases assuming no mechanical failures:

  1. The hold coils are not energized for those five rows
  2. Hold is energized but so is the counterwound selection coil
  3. I have assembled the punch incorrectly which is blocking those interposers from retracting

I think that the hold coils are all wired in parallel, with one source of energizing power. Unless the coil is defective, all should be energized and either all twelve punch or all twelve don't. I can test for magnetic attraction on the ends of the twelve solenoids using a metal rod or screwdriver.

The counterwound coil is driven by an amplifier/driver card in the punch based on signals coming over the cable from the 1131 adapter logic cards. I could have a bad card in either location or the cable might not be fully engaged. I will check all these conditions when I get to the machine tomorrow. Today, I am working on the 729 tape drives on the 1401 computers at the Computer History Museum.

WAITING WAITING WAITING

Waiting for the metalworker to respond to my specs and request for an estimate. By the weekend without a response, I will go find another metalworker.

Waiting for the hard drive recovery service to complete its attempt and tell me whether my files are recovered. They would be delivered by FTP so once they respond and if I pay, I can be accessing them immediately.

Tuesday, May 24, 2016

1442 back together, testing now, plus rebuilding laptop

1442 CARD READER/PUNCH RESTORATION

I have installed one of the linkages and was working on the second one by lunchtime. I also located the place for most of the remaining parts in the bin, which are part of the punch eject roller and its belt drive. However, there are just a few mystery parts which worry me, particularly two of them. A circlip which suggests a roller somewhere that is not properly secured on its post, and a U shaped pin which might be from deep inside the punch unit.

Hand operating the punch unit, I see it drive all 12 punches through their dies and advance everything suitably, but until I have this under power I won't know if the interposers work to block punching each of the 12 rows.

It was quite challenging to handle each of the remaining tasks, given their nearly inaccessible locations, lack of enough room to use any of my tools and the challenge of stretching the rubber drive belts over the edges of the pulleys. I improvised with a tiny socket held with itty bitty vice-grips, and similar improvisations.

By mid afternoon, I had the linkage on, the punch eject roller parts assembled, belts in place and everything ready to button up for testing. I had dropped the circlip down into the machinery somewhere while trying to fit it somewhere it didn't belong. I also lost a lockwasher for the bolt that holds the punch eject pulley on.

Remaining mystery parts are a small nut, a medium size washer and the small U shaped thing. I hope I never discover where those parts go, since that would be discovered when some part of the machine malfunctioned.

I fired up the system, loaded cards (push Start button to get one card to feed into the pre-read station), and did Non-Process Runout (NPRO) to clear cards. Cards that exit the punch station still get stuck in the cornering station, where cards stop after exiting the punch and them are picked up by the stackers which begins moving the card at right angles to the original travel direction.

More seriously, while doing an NPRO, the punch unit laced the card in rows 4, 5, 6, 7 and 8 although this was a real punch operation. When punching, the card sits in the punch station and is moved column by column through the operation of the incremental drive, timed between each punch cycle. In this case, while the punches were pushing down the card was trying to fly through the punch station, using the punch eject roller and not the incremental drive.

This might be an interaction between my virtual 1442 logic sitting in the fpga and the IBM supplied adapter logic in the 1130. I removed the jumper that disables the IBM adapter from reacting to XIO instructions, which was in place while I tested the virtual 1442 functions. Now, both FPGA and 1130 logic are active which might introduce problems. Still, punching randomly while cards are cleared with an NPRO is not good.

RECOVERY OF CRASHED LAPTOP

My first two actions on the new laptop image were applying all the windows updates and setting up a Crashplan subscription to make sure I never again lose all my work. I am waiting to see if the recovery lab can retrieve my data, but my drive arrived in the afternoon Friday of a three day weekend (Victoria day in Canada) so that my drive was just opened and logged today.  I am hopeful but not wildly optimistic; I should know in a week or two.

Next up I started installing software I use, such as the Python environment and the wxPython GUI code. The longest was the download and install of the Xilinx Vivado toolchain for the fpgas, requiring downloads of more than 3GB of data.