VT52 DECscope Maintenance Manual

Appendix A
Reference Data

A.1 PROM, ROM Cross Reference Chart

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.

Figure A-1 PROM Set Layout
Table A-1 Compatible Character Generator Chips for PROM/ROM Variations
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
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.

A.2 IC Pin Location Drawings