Not all Character Generator chips will work properly with all PROM/ROM sets. Table A-1 lists the PROM/ROM variations and their compatible Character Generator chips. Figure A-1 shows the PROM set layout.
| Variations | PROM Set Label | ROM Set Part No. | Character Revision | Generator Chip Part No. |
|---|---|---|---|---|
| VT52 with serial numbers up to WF 03660, and part no. 04600, and VT52 with copiers use the 54-11743 (no variation) ROM/UART board. | K1 or L1-3 | 23-119A9 | * or A | 23-001B400 or 23-002B400 |
| K1 or L1-2 | 23-120A9 | |||
| K1 or L1-4 | 23-121A9 | |||
| K1 or L1-1 | 23-122A9 | |||
| Basic VT52, supporting the Printer Interface Module (PIM), uses the 54-11743-04 ROM boards. | M4-3 | 23-124A9 | A | 23-002B400 |
| M3-2 | 23-125A9 | |||
| M4-4 | 23-126A9 | |||
| M4-1 | 23-127A9 | |||
| VT55, with/without copier use the 54-11743-02 ROM boards. | 128 | 23-128A9 | A | 23-002B400 |
| 129 | 23-129A9 | |||
| 130 | 23-130A9 | |||
| 131 | 23-131A9 | |||
| Note that the * Character Generator boards will not work properly with M4 PROMs | ||||
| 400 denotes that on the Character Generator chip the part number may end in 400 or 4. | ||||