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+Custom I/O devices used with ITS.
+
+| Code | Name | Description | Used in
+| --- | --- | --- | ---
+| 20 | PDP | Inter processor interrupt | ITS, and others...
+| 20 | DSDEV | Deselection Device | ITS, SLAVE, TOBTVJ, FLIGHT, 10RUN
+| 24 | DSDEV | ITS
+| 70 | STK | Stanford Keyboard | ITS
+| 70 | COD | Morse code F1 92Mhz broadcast output device | ITS
+| 270 | DF | Type 270 PDP-6 Disk Controller | DECUUO
+| 270 | | | KLDCP
+| 374 | | Chess clock | ITS
+| 400 | MTY | Morton Multiplex Box | ITS
+| 420 | WCNSLS | Spacewar Consoles | SPCWAR, DAZDRT, HEART, FLIGHT, LD10
+| 420 | CLR | Color scope | TJ6, TOBTVJ, DS SLAVE
+| 424 | FI | DM IMP Interface | ITS, GUNNER, NCPUP
+| 454 | | D/A
+| 460 | IMP | KA IMP Interface | ITS
+| 460 | | | FLIGHT
+| 464 | | New LPT
+| 470 | | Chaosnet | ITS
+| 470 | | GE Typeout
+| 500 | PDCLK | Paul DeCoriolis Clock | ITS, PDSET
+| 500 | | KL-UDGE | ITS
+| 504 | TIP | Tip Break
+| 510 | | Another D/A???
+| 514 | RBTCON | Robot Console | DS SLAVE, ITS
+| 540 | | Serial IOB
+| 560 | | Radio Pot Box
+| 564 | | Arm Tactile Sense
+| 570 | OMX | Output Multiplexor (D/A) | ITS, DS SLAVE
+| 574 | IMX | Input Multiplexor (A/D) | ITS, DAZDRT, DS SLAVE
+| 600 | NTY | Knight TTY Kludge | ITS
+| 604 | DPK | Datapoint Kludge | ITS, LOCK
+| 610 | DC0 | 2314 Disk Control | ITS
+| 614 | DC1 | 2314 Disk Control | ITS
+| 620 | NVDX | Vidissector X | DS SLAVE, ITS
+| 624 | NVDY | Vidissector Y | DS SLAVE, ITS
+| 630 | NVDT | Vidissector T (deflection delay) | DS SLAVE, ITS
+| 654 | PLT | Calcomp Plotter | ITS
+| 660 | | Data Disc
+| 664 | | Data Disc
+| 704 | | 2311 Control
+| 710 | CLK1 | Holloway Clock | BIG, (ITS commented out)
+| 714 | CLK2 | Holloway Clock | BIG
+| 724 | | | BIG
+| 730 | | | BIG
+| 744 | | Output Mux
+| 750 | | GE Typeout
+| 754 | |  Old Vidissector
+| 760 | | PDP-6 Temporary Direct Sense Hookups | ROUT, 340TIT, MLIFE, LD10, ITS, TECO, PORNIS
+| 764 | | Input Mux | DS SLAVE, FLIGHT