Restoration of 1053 Console Printer of the IBM 1130 system is nearly complete

 DISPLACING GUMMED UP OLD LUBRICANTS

The major challenge for any IBM Selectric based machine is the lubricants that were used in the 1960s and 1970s. They turn to sludge, absorb dust and harden in place. The standard way to deal with this is to dunk a mechanism in a solvent bath, then reapply oil or grease at the relevant points. 

The I/O Selectrics, those with microswitches and solenoids to allow them to be controlled by computer, pose an added challenge. those electrical parts need to be removed before a solvent bath, which is a labor intensive process that must be followed by a total reset of all the adjustments. 

However, I make use of my secret weapon. Nye #80 clock oil is so light that it seeps between the gunky materials and the metal parts, floating them away and restoring movement. It doesn't take long - drop on some of the oil and move the parts for a few minutes until they are turning freely. 

EXERCISING FUNCTIONS ON BENCH

I have the typewriter mechanism out on a workbench where I can run it under motor power as well as with hand cycling. The functions can all be triggered without connection to a computer. The 1053 was built with three buttons on the front to activate the Tab, Space and Carrier Return functions. 

The solenoids for computer commanded motions such as space, backspace, tab, line feed and return have links to the mechanism that can easily be tripped. Finally, the seven solenoids that trigger printing a character can be pushed to activate the mechanism. 

Those seven solenoids select the chosen tilt and rotate position, plus when one or more are triggered it fires off a cycle of the print mechanism. Two signals allow selection of the four horizontal bands which are chosen by tilting the ball mechanism. Four signals allow selection of direction of rotation and which of the 10 vertical columns of letters are selected on that hemisphere of the typeball. 

An additional Auxiliary trigger is provided because there is one character position on the typeball that is reached with all the other solenoids left unselected. That is, the tilt tier encoded by 00 and the rotation column encoded by 0000 is a valid character that could be printed. In order to fire off a print cycle, since none of the other solenoids are activated, the Aux solenoid was implemented to handle this special case.

Testing rotation and tilt to chosen characters on typeball

 PLANNING TO SET UP MECHANISM TO DRIVE THIS ON THE BENCH

The solenoids that shift to upper or lower case, select the character to print, command returns, line feeds, spaces, backspaces and tabs, as well as choosing between the black and red section of the ribbon, are all fed with common +48V DC and the other side is pulled to ground by a transistor to activate the electromagnet. 

I can create a quick and dirty method of triggering these functions by jumpering the solenoid(s) I want to trip to a common ground and then blipping the 48V on for a short interval. The only reason I haven't done it already is that I don't have a handy 48V supply with enough oomph to handle the current of up to six simultaneous solenoids. 

While I can fire off the movement functions with the motor spinning, it is too hard to push a combination of seven solenoids simultaneously and for a brief moment to fire off selection of one character. I can use the hand cycle wheel to select the solenoids by hand and then crank the machine to see that the proper tilt and rotate is achieved, but I would want to see this work at full speed before I was certain it was good enough to go back onto the 1130. 

STATE OF THE 1053 AS OF THIS EVENING

The functions that are working well now, both manually and under motor power, are:

• Space
• Backspace
• Carrier Return
• Line Feed

I have yet to fully test these functions, but expect that they work properly:

• Shift to upper case
• Shift to lower case
• Shift to black ribbon half
• Shift to red ribbon half

The case shifts will be easy to validate, but the ribbon halves depend on firing characters at motor speed which I can't do with my fully manual testing methods. If I get the test mechanism working that I described above, I can stick on the platen, ribbon and some paper to test the color being typed and shift between them. 

The one function that I know is not working properly is Tab. It appears that there is a missing spring or other issue in that one function. It fires erratically from the button and won't fire at all when pulling on the solenoid link. When it does fire it resets as soon as the activation cycle is over, whereas it should stick on while the carrier moves to the right, only dropping a pawl into the escapement when a set tab position is reached.