Motor power test of the 1053 functionality - everything works properly

USING MY SMS CONNECTOR SYSTEM TO HOOK TO THE 1053 CABLES

I developed a PCB that I can use to make SMS connectors, both the male 'paddle cards' and the female sockets, since the typewriter has one of each type that plug into the IBM 1130. This is on github under my account in case others want to use them.

When used as a socket, the flat conductor 'fingers' of the socket and the flat conductor fingers of the 1053 paddle card don't make good contact across all thirteen fingers due to flexing of the PCBs. To solve this, I bought some surface mount RF finger components - little parts that solder onto the fingers and have a springy top to ensure contact. After soldering these on a socket PCB I had perfect connectivity between the 1053 male paddle card and my socket. 

These are wired into the relay system I set up to trigger the 1053 solenoids with appropriate duration to activate all the functions of the typewriter that are controlled by the mainframe. The breadboard unit has a timer circuit to produce the correct length pulse which turns on the +48V, energizing every solenoid that is grounded by a relay on the large relay board. 

CHECKING PRINT CHARACTERS

I first set up a set of characters to verify that I could select the eleven rotate positions from -5 to +5 as well as the four tilt levels properly. It was enough to have one character from each tilt level and one from each of the eleven rotates; I could overlap the test so that four characters tested the tilt plus four of the eleven rotates, then another seven characters would fill out the rotate completement. 

Then I had to do another eleven characters to test the rotate positions on the other side after shifting the ball from upper to lower case. Only when all 22 characters and the shifts were verified was I satisfied that character printing was correct. 

Visually I inspected the output to refine the vertical position of the platen, so that a character is evenly inked top and bottom. I also inspected to verify that the carrier movement at the end of the print cycle does not produce any smearing and that letters are evenly spaced across the line. 

Perfect!

VERIFYING THE UP SHIFT AND DOWN SHIFT OPERATIONS

The up shift and down shift solenoids won't activate with the very brief pulse used to print characters or trigger the other operations, but a slightly longer activation causes a crisp shift to the requested case. Again, works fine. 

VERIFYING DUAL COLOR PRINTING

After tweaking the tension, I could command printing from the top or bottom half of the ribbon, thus printing in black or red ink. 

VERIFYING SPACE BUTTON AND SOLENOID

When I push the Space button on the front of the typewriter, it cleanly moves one column to the right for each push. Activating the space solenoid does the same and I could fire off a string of rapid spaces which moved the carrier cleanly. 

VERIFYING BACKSPACE

My test setup sent backspace solenoid commands to the typewriter and I verified it moved precisely one column back on each iteration.

VERIFYING TAB BUTTON AND SOLENOID

Pushing the Tab button on the front of the typewriter causes the carrier to zoom to the right and stop at the column where a tab is in the set position. Firing the tab solenoid does the same. 

VERIFYING CARRIER RETURN BUTTON AND SOLENOID

Pushing the Return button on the front of the 1053 causes the carrier to race leftwards and stop exactly at the left margin, ready to resume printing at that column. The carrier return solenoid does this as well. The return function also triggers an Index operation, thus we move down a line and return to the left margin in the same operation. 

VERIFYING INDEX

Activating the index solenoid rotates the platen to move the paper up one line position at a time. 

VERIFYING MARGIN LEVERS WORK PROPERLY

Moving the left and right margin levers, I verified that they move smoothly and latch into the chosen column when released. The return stops at the left margin, the bell rings when you approach the right margin and everything is as it should be. 

VERIFYING GANG CLEAR OF TAB SETTINGS

When the tab lever is rotated on the front of the typewriter, it will either set or clear the tab at the current column. A convenient feature of Selectric typewriters is gang clearing. This means that with the carrier at the right margin, if you hold the tab lever in the clear position and hit return, the machine clears all the tabs between the starting point and the left margin where the carrier stops. This worked properly. 

CONDITION ASSESSMENT

Having passed all the tests above, the 1053 is now able to perform everything it needs to do before the 1053 is reinstalled onto the IBM 1130. 

INSTALLATION ON THE MACHINE

I connected the front panel to the typewriter and placed the unit under the display pedestal. I ran out of time to finish the installation but will perform this tomorrow when I get back to the shop. 

I have to do the following:

• install the rod that connects the front panel tab Clear/Set lever
• reconnect the forms out microswitch on the cover to the typewriter
• put the cover on and snap it into place
• insert the paper feed rollers and related parts
• put on the rod which holds the pin feed arms in place
• install the platen with its pin feed arms
• route the cables down through the 1130 to under the disk drive
• plug in the two signal cables to the SMS peripheral connector bank
• plug in the SMS power paddle connector to the power bank