Loaded and ran hand loop to test out the 1052 console printer (typewriter)

THIS TESTS BOTH THE CONTROLLER LOGIC AND THE TYPEWRITER DEVICE

Most of my tests are of controllers that will operate with printers or card readers at the VCF's museum that are yet to be restored. Thus I am taking advantage of my own peripherals, to the extent that they work okay, to verify the controller logic only. 

In contrast, for the console printer and keyboard, the device is part of the 1130 so the test is both of the controller logic and of the proper operation of the device. I have already validated the keyboard device and controller logic; this is the typewriter side of the console. 

HAND LOOP TO PRINT CHARACTERS BASED ON CONSOLE ENTRY SWITCH SETTINGS

The hand loop reads the console entry switches and alternates sending the left eight and right eight bits to the printer. I verified that almost all of the functionality of the printer that way. It shifted between red and black ribbon stripes, it shifted as appropriate between the upper and lower case sides of the typeball, it typed characters properly from all rotate values -5 to +5, it performed tab, backspace, line feed, and carrier returns upon command. It detected the right margin and automatically inserted a carrier return. 

One function failed to operate - space. The space button on the typewriter works properly, but when sending the code x2100 via an XIO command, the typewriter silently ignored the request. Much of the logic involved in commanding a space is shared with logic controlling the R2 selection, yet I printed characters using R2. The unique path is 

• one three input NAND gate
• a driver gate to ground the solenoid (whose other end is at 48V)
• a trace over to the connector for the cabling from the logic gate to the SMS paddle card connector
• a trace on PF2 SMS paddle card
• a wire into the typewriter
• and a solenoid in the typewriter plus a reverse quenching diode. 

When I next get to the shop, I will validate the path continuity, the proper signal when processing a space request, and the energizing of the solenoid. If the issue is electrical, I will find it this way. 

One operational cam serves tab, space and backspace, thus it is working. The same trigger is used for the pushbutton as the solenoid, so that works as well. It may be that the linkage from the solenoid to pull the space trigger is not adjusted correctly or gummed up.