Friday, May 27, 2022

Completed all of central processing unit, now entering device controller ALD pages

 ONLY DEVICE CONTROLLER LOGIC REMAINS TO ENTER

The ALD pages at the end of volume 3 and the remainder of volume 4 cover the device controller logic that resides inside the 1130 system. Each device, if configured into the system, has controller logic to react to XIO instructions, deal with interrupts, status words and handle the mechanics of input-output for the device. If a device is not part of the system, its logic is not installed. 

Even though keyboard, console entry switches and console printer are included on every system, they are treated like the other peripheral devices. I have completed everything else in the system and will now only be entering the controller logic for the devices for which I have ALD pages. These are:

  • Keyboard
  • Console Entry Switches
  • Console Printer (1053)
  • Internal disk drive
  • 1134 paper tape reader
  • 1055 paper tape punch
  • 1627 plotter
  • 1132 line printer
  • 1442 card reader/punch
  • 2501 card reader
Other devices that can attach to the 1130 system with controller logic inside are the 1231 Optical Mark Sense Reader and the Synchronous Communications Adapter. The 1130 I am restoring for the museum in Maryland has the SCA configured but I lack the logic pages. I may have pages for the SCA from another 1130 system, in which case I will enter them in the database.

Some devices that could be attached to an IBM 1130 system were only supported by attachment to the 1133 Multiplexor box. This contained the controller logic for those devices, and in turn it attached to the 1130 system through the Storage Access Channel (SAC) feature which is documented as part of the processor. I have never come across ALDs for the 1133 or the controller logic contained inside. Devices that attach through the 1133 or the SAC include:
  • 1403 line printer
  • 2310 additional disk drives
  • 2420 tape drives
  • 2250 graphics terminal
  • 2311 disk drives
The processor itself, before I began entering the device controller signals, had 2,799 signal pins listed in the database. As previously stated, these are output signals that flow to other ALD pages as well as signals that flow between compartments (backplanes). It does not include signals that flow on a backplane purely within an ALD page. 

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