FINAL RESTORATION REPAIRS AND ADJUSTMENTS FOR THE TYPEWRITER
I worked for several hours to clean up all the outstanding issues with the Selectric typewriter based Console Printer. It was on the bench, but I wired up AC to the motor so that I could test both by hand and under power.
The Space pushbutton was not reliably tripping the operational cam. I removed part of the plate in front of the levers and screwed in the standoff that positions the lever so that it now cleanly strikes the cam trigger.
The tab setting sliders for each column were in many cases still too sticky to move easily when setting or clearing a tab stop at that column, I flooded them all with my super light oil and worked every column until they were all sliding well between the two positions.
The mainspring did not have enough tension to maintain decent speed when the tab movement reached the columns on the right. I added a couple of turns of tension.
The shift mechanism that rotates the typeball between the upper case and lower case hemispheres was sticking in upper case even when the solenoids had released the control lever. This lever has a spring that should have snapped it back immediately but something was binding. I lubricated the hinge points where the control lever pivoted, working it back and forth, until I was satisfied that it would jump back as soon as it was released.
I checked all the rotate and tilt settings, finding them all spot on. This typewriter was very well cared for and properly adjusted, making its restoration much easier than some where I have received mechanisms in terrible condition and maladjustment.
The print shaft timing needed to be set because I had to release the gear in order to work the print mechanism when I first flushed out the glue-like stale lubricant which left it frozen in place. The procedure is straightforward and I followed it. I installed a half-cycle tool on the machine which will stop the print mechanism at the halfway point through a print operation.
First the gear is loosened so the print shaft wont turn. Setting up a specific requested character with the selection solenoids, I brought the typehead to its latched position ready to strike forward. I then hand rotated the print shaft until the detent that selects the rotate position was halfway out of the tooth on the typeball. The half-cycle tool was removed and I moved that part of the mechanism forward until the detent just strikes the bottom tip of the tooth. That is where I tightened down the print gear.
I hand selected and half-cycled various rotate positions, verifying that the ball was locked in the proper position and was rotated appropriately if the detent was released. I then turned on the motor and tried various characters, particularly the extremes of +5 and -5 whose proper operation depends on a slew of prior adjustments (which all seemed correct). The correct character was typed in all cases.
I installed a new-old-stock bicolor ribbon (red along the top and black along the bottom). I then adjusted the ribbon shift mechanism until by selecting the proper solenoid, the letters were typed in black or in red.
I installed the plastic shields that protect the mechanisms inside the Selectric from falling debris - typically that would be paper clips, hair clips and other office materials in the office setting for which the typewriter was designed.
Finally, I reinstalled the cover over the typewriter mechanism, connecting up the forms check microswitch which detects whether paper is feeding into the typewriter. There is a faceplate that is connected to the 1130 logic but has to be attached to the front of the typewriter. It has the plastic buttons for Tab, Space and Return that push the metal buttons on the typewriter. It has a window which shows the current column position of the carrier and the positions of the left and right margins. On the plate is a rocker which can be moved to set or clear the tab stop at the current column. Unrelated to the typewriter, it also holds the sixteen console entry switches that are another peripheral device used by the 1130.
TYPEWRITER PUT ON THE MACHINE AND CABLES ROUTED DOWN BELOW
The typewriter was placed on its mounting point just in front of the keyboard and underneath the display light panel. The platen and faceplate are not yet installed on the typewriter, because I ran out of time in the shop today.
The console printer has two SMS paddle cards which route signals between the 1130 and the 1052 typewriter, plus an SMS power paddle card that provides the 115VAC for the motor, +48V for the solenoids and +12V for the feedback microswitch circuits. I have the two signal cards installed but have not yet plugged in the power card.
The faceplate will be attached to the typewriter after carefully connecting a tie-rod that connects the tab set/clear rocker with the actual tab mechanism at the left rear of the typewriter.
I am feeling confident enough in the typewriter that I will move directly onto running the 1132 printer diagnostic which I had loaded into core earlier. Alternatively I could have run a hand loop first, and then loaded the 1052 diagnostic to test the typewriter fully.
MODIFIED THE ARDUINO, ASSEMBLED THE MEMORY LOADER STACK AND TESTED
I took the Arduino Mega 2560 that I had loaded with the code for the DMA/Cycle Steal loader and prepared it for 1130 use. First, I removed a power pass transistor that powers the whole board with USB power if the main power connection is not active. I only want the board to power up when the 1130 is powered on. Second, I installed a 10uF capacitor between the Reset and Ground pins of the Arduino which block it from resetting the code when a serial connection is opened over USB.
With the shield plugged onto the Arduino, I brought it over and connected the cables from the 1130 to this instead of the board I had tested yesterday. I used it to successfully load memory with code including the 1132 diagnostic I will use tomorrow. The stack was then unplugged and the original stack returned to service. This new stack is now ready to go to the System Source Museum where I can install the header blocks, link them to the 1130 backplane with wire-wrap, provide 12V from the 1130 to the shield, route a long USB cable to outside of the 1130 cabinet, install the three ribbon cables, and physically secure the stack in place on the machine.
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