U35 Truth Tables

Reverse engineered Apple II hardware

U35 Truth Tables

The IC labeled “1982NNCE” and designated U35 on the schematic is a 74187, which is a fast 256 by 4-bit ROM. On the Accelerator II card it is being used to store the truth table of four logic functions used for address decoding.

Output DRAM_CYCLE (DO1)

Truth table:

EXT_LANGCARD_SOFTSW (A7) LANGCARD_ACCESS_EN (A6) LA15 (A5) LA14 (A2) LA13 (A3) LA12 (A1) LR/W (A4)   DRAM_CYCLE (DO1)
0 0 0 0 0 0 0   1
0 0 0 0 0 0 1   1
0 0 0 0 0 1 0   1
0 0 0 0 0 1 1   1
0 0 0 0 1 0 0   1
0 0 0 0 1 0 1   1
0 0 0 0 1 1 0   1
0 0 0 0 1 1 1   1
0 0 0 1 0 0 0   1
0 0 0 1 0 0 1   1
0 0 0 1 0 1 0   1
0 0 0 1 0 1 1   1
0 0 0 1 1 0 0   1
0 0 0 1 1 0 1   1
0 0 0 1 1 1 0   1
0 0 0 1 1 1 1   1
0 0 1 0 0 0 0   1
0 0 1 0 0 0 1   1
0 0 1 0 0 1 0   1
0 0 1 0 0 1 1   1
0 0 1 0 1 0 0   1
0 0 1 0 1 0 1   1
0 0 1 0 1 1 0   1
0 0 1 0 1 1 1   1
0 0 1 1 0 0 0   0
0 0 1 1 0 0 1   0
0 0 1 1 0 1 0   0
0 0 1 1 0 1 1   0
0 0 1 1 1 0 0   0
0 0 1 1 1 0 1   0
0 0 1 1 1 1 0   0
0 0 1 1 1 1 1   0
0 1 0 0 0 0 0   1
0 1 0 0 0 0 1   1
0 1 0 0 0 1 0   1
0 1 0 0 0 1 1   1
0 1 0 0 1 0 0   1
0 1 0 0 1 0 1   1
0 1 0 0 1 1 0   1
0 1 0 0 1 1 1   1
0 1 0 1 0 0 0   1
0 1 0 1 0 0 1   1
0 1 0 1 0 1 0   1
0 1 0 1 0 1 1   1
0 1 0 1 1 0 0   1
0 1 0 1 1 0 1   1
0 1 0 1 1 1 0   1
0 1 0 1 1 1 1   1
0 1 1 0 0 0 0   1
0 1 1 0 0 0 1   1
0 1 1 0 0 1 0   1
0 1 1 0 0 1 1   1
0 1 1 0 1 0 0   1
0 1 1 0 1 0 1   1
0 1 1 0 1 1 0   1
0 1 1 0 1 1 1   1
0 1 1 1 0 0 0   0
0 1 1 1 0 0 1   0
0 1 1 1 0 1 0   1
0 1 1 1 0 1 1   1
0 1 1 1 1 0 0   1
0 1 1 1 1 0 1   1
0 1 1 1 1 1 0   1
0 1 1 1 1 1 1   1
1 0 0 0 0 0 0   1
1 0 0 0 0 0 1   1
1 0 0 0 0 1 0   1
1 0 0 0 0 1 1   1
1 0 0 0 1 0 0   1
1 0 0 0 1 0 1   1
1 0 0 0 1 1 0   1
1 0 0 0 1 1 1   1
1 0 0 1 0 0 0   1
1 0 0 1 0 0 1   1
1 0 0 1 0 1 0   1
1 0 0 1 0 1 1   1
1 0 0 1 1 0 0   1
1 0 0 1 1 0 1   1
1 0 0 1 1 1 0   1
1 0 0 1 1 1 1   1
1 0 1 0 0 0 0   1
1 0 1 0 0 0 1   1
1 0 1 0 0 1 0   1
1 0 1 0 0 1 1   1
1 0 1 0 1 0 0   1
1 0 1 0 1 0 1   1
1 0 1 0 1 1 0   1
1 0 1 0 1 1 1   1
1 0 1 1 0 0 0   0
1 0 1 1 0 0 1   0
1 0 1 1 0 1 0   0
1 0 1 1 0 1 1   1
1 0 1 1 1 0 0   0
1 0 1 1 1 0 1   1
1 0 1 1 1 1 0   0
1 0 1 1 1 1 1   1
1 1 0 0 0 0 0   1
1 1 0 0 0 0 1   1
1 1 0 0 0 1 0   1
1 1 0 0 0 1 1   1
1 1 0 0 1 0 0   1
1 1 0 0 1 0 1   1
1 1 0 0 1 1 0   1
1 1 0 0 1 1 1   1
1 1 0 1 0 0 0   1
1 1 0 1 0 0 1   1
1 1 0 1 0 1 0   1
1 1 0 1 0 1 1   1
1 1 0 1 1 0 0   1
1 1 0 1 1 0 1   1
1 1 0 1 1 1 0   1
1 1 0 1 1 1 1   1
1 1 1 0 0 0 0   1
1 1 1 0 0 0 1   1
1 1 1 0 0 1 0   1
1 1 1 0 0 1 1   1
1 1 1 0 1 0 0   1
1 1 1 0 1 0 1   1
1 1 1 0 1 1 0   1
1 1 1 0 1 1 1   1
1 1 1 1 0 0 0   0
1 1 1 1 0 0 1   0
1 1 1 1 0 1 0   0
1 1 1 1 0 1 1   0
1 1 1 1 1 0 0   0
1 1 1 1 1 0 1   0
1 1 1 1 1 1 0   0
1 1 1 1 1 1 1   0

Output ADDR_PAGE_Cx (DO2)

Truth table:

LA15 (A5) LA14 (A2) LA13 (A3) LA12 (A1)   ADDR_PAGE_Cx (DO2)
0 0 0 0   0
0 0 0 1   0
0 0 1 0   0
0 0 1 1   0
0 1 0 0   0
0 1 0 1   0
0 1 1 0   0
0 1 1 1   0
1 0 0 0   0
1 0 0 1   0
1 0 1 0   0
1 0 1 1   0
1 1 0 0   1
1 1 0 1   0
1 1 1 0   0
1 1 1 1   0

Output EXT_BUS_CYCLE0 (DO3)

Truth table:

EXT_LANGCARD_SOFTSW (A7) LANGCARD_ACCESS_EN (A6) LA15 (A5) LA14 (A2) LA13 (A3) LA12 (A1) LA10_XOR_LA11 (A0) LR/W (A4)   EXT_BUS_CYCLE0 (DO3)
0 0 0 0 0 0 0 0   0
0 0 0 0 0 0 0 1   0
0 0 0 0 0 0 1 0   1
0 0 0 0 0 0 1 1   0
0 0 0 0 0 1 0 0   0
0 0 0 0 0 1 0 1   0
0 0 0 0 0 1 1 0   0
0 0 0 0 0 1 1 1   0
0 0 0 0 1 0 0 0   1
0 0 0 0 1 0 0 1   0
0 0 0 0 1 0 1 0   1
0 0 0 0 1 0 1 1   0
0 0 0 0 1 1 0 0   1
0 0 0 0 1 1 0 1   0
0 0 0 0 1 1 1 0   1
0 0 0 0 1 1 1 1   0
0 0 0 1 0 0 0 0   1
0 0 0 1 0 0 0 1   0
0 0 0 1 0 0 1 0   1
0 0 0 1 0 0 1 1   0
0 0 0 1 0 1 0 0   1
0 0 0 1 0 1 0 1   0
0 0 0 1 0 1 1 0   1
0 0 0 1 0 1 1 1   0
0 0 0 1 1 0 0 0   0
0 0 0 1 1 0 0 1   0
0 0 0 1 1 0 1 0   0
0 0 0 1 1 0 1 1   0
0 0 0 1 1 1 0 0   0
0 0 0 1 1 1 0 1   0
0 0 0 1 1 1 1 0   0
0 0 0 1 1 1 1 1   0
0 0 1 0 0 0 0 0   0
0 0 1 0 0 0 0 1   0
0 0 1 0 0 0 1 0   0
0 0 1 0 0 0 1 1   0
0 0 1 0 0 1 0 0   0
0 0 1 0 0 1 0 1   0
0 0 1 0 0 1 1 0   0
0 0 1 0 0 1 1 1   0
0 0 1 0 1 0 0 0   0
0 0 1 0 1 0 0 1   0
0 0 1 0 1 0 1 0   0
0 0 1 0 1 0 1 1   0
0 0 1 0 1 1 0 0   0
0 0 1 0 1 1 0 1   0
0 0 1 0 1 1 1 0   0
0 0 1 0 1 1 1 1   0
0 0 1 1 0 0 0 0   1
0 0 1 1 0 0 0 1   1
0 0 1 1 0 0 1 0   1
0 0 1 1 0 0 1 1   1
0 0 1 1 0 1 0 0   1
0 0 1 1 0 1 0 1   1
0 0 1 1 0 1 1 0   1
0 0 1 1 0 1 1 1   1
0 0 1 1 1 0 0 0   1
0 0 1 1 1 0 0 1   1
0 0 1 1 1 0 1 0   1
0 0 1 1 1 0 1 1   1
0 0 1 1 1 1 0 0   1
0 0 1 1 1 1 0 1   1
0 0 1 1 1 1 1 0   1
0 0 1 1 1 1 1 1   1
0 1 0 0 0 0 0 0   0
0 1 0 0 0 0 0 1   0
0 1 0 0 0 0 1 0   1
0 1 0 0 0 0 1 1   0
0 1 0 0 0 1 0 0   0
0 1 0 0 0 1 0 1   0
0 1 0 0 0 1 1 0   0
0 1 0 0 0 1 1 1   0
0 1 0 0 1 0 0 0   1
0 1 0 0 1 0 0 1   0
0 1 0 0 1 0 1 0   1
0 1 0 0 1 0 1 1   0
0 1 0 0 1 1 0 0   1
0 1 0 0 1 1 0 1   0
0 1 0 0 1 1 1 0   1
0 1 0 0 1 1 1 1   0
0 1 0 1 0 0 0 0   1
0 1 0 1 0 0 0 1   0
0 1 0 1 0 0 1 0   1
0 1 0 1 0 0 1 1   0
0 1 0 1 0 1 0 0   1
0 1 0 1 0 1 0 1   0
0 1 0 1 0 1 1 0   1
0 1 0 1 0 1 1 1   0
0 1 0 1 1 0 0 0   0
0 1 0 1 1 0 0 1   0
0 1 0 1 1 0 1 0   0
0 1 0 1 1 0 1 1   0
0 1 0 1 1 1 0 0   0
0 1 0 1 1 1 0 1   0
0 1 0 1 1 1 1 0   0
0 1 0 1 1 1 1 1   0
0 1 1 0 0 0 0 0   0
0 1 1 0 0 0 0 1   0
0 1 1 0 0 0 1 0   0
0 1 1 0 0 0 1 1   0
0 1 1 0 0 1 0 0   0
0 1 1 0 0 1 0 1   0
0 1 1 0 0 1 1 0   0
0 1 1 0 0 1 1 1   0
0 1 1 0 1 0 0 0   0
0 1 1 0 1 0 0 1   0
0 1 1 0 1 0 1 0   0
0 1 1 0 1 0 1 1   0
0 1 1 0 1 1 0 0   0
0 1 1 0 1 1 0 1   0
0 1 1 0 1 1 1 0   0
0 1 1 0 1 1 1 1   0
0 1 1 1 0 0 0 0   1
0 1 1 1 0 0 0 1   1
0 1 1 1 0 0 1 0   1
0 1 1 1 0 0 1 1   1
0 1 1 1 0 1 0 0   0
0 1 1 1 0 1 0 1   0
0 1 1 1 0 1 1 0   0
0 1 1 1 0 1 1 1   0
0 1 1 1 1 0 0 0   0
0 1 1 1 1 0 0 1   0
0 1 1 1 1 0 1 0   0
0 1 1 1 1 0 1 1   0
0 1 1 1 1 1 0 0   0
0 1 1 1 1 1 0 1   0
0 1 1 1 1 1 1 0   0
0 1 1 1 1 1 1 1   0
1 0 0 0 0 0 0 0   0
1 0 0 0 0 0 0 1   0
1 0 0 0 0 0 1 0   1
1 0 0 0 0 0 1 1   0
1 0 0 0 0 1 0 0   0
1 0 0 0 0 1 0 1   0
1 0 0 0 0 1 1 0   0
1 0 0 0 0 1 1 1   0
1 0 0 0 1 0 0 0   1
1 0 0 0 1 0 0 1   0
1 0 0 0 1 0 1 0   1
1 0 0 0 1 0 1 1   0
1 0 0 0 1 1 0 0   1
1 0 0 0 1 1 0 1   0
1 0 0 0 1 1 1 0   1
1 0 0 0 1 1 1 1   0
1 0 0 1 0 0 0 0   1
1 0 0 1 0 0 0 1   0
1 0 0 1 0 0 1 0   1
1 0 0 1 0 0 1 1   0
1 0 0 1 0 1 0 0   1
1 0 0 1 0 1 0 1   0
1 0 0 1 0 1 1 0   1
1 0 0 1 0 1 1 1   0
1 0 0 1 1 0 0 0   0
1 0 0 1 1 0 0 1   0
1 0 0 1 1 0 1 0   0
1 0 0 1 1 0 1 1   0
1 0 0 1 1 1 0 0   0
1 0 0 1 1 1 0 1   0
1 0 0 1 1 1 1 0   0
1 0 0 1 1 1 1 1   0
1 0 1 0 0 0 0 0   0
1 0 1 0 0 0 0 1   0
1 0 1 0 0 0 1 0   0
1 0 1 0 0 0 1 1   0
1 0 1 0 0 1 0 0   0
1 0 1 0 0 1 0 1   0
1 0 1 0 0 1 1 0   0
1 0 1 0 0 1 1 1   0
1 0 1 0 1 0 0 0   0
1 0 1 0 1 0 0 1   0
1 0 1 0 1 0 1 0   0
1 0 1 0 1 0 1 1   0
1 0 1 0 1 1 0 0   0
1 0 1 0 1 1 0 1   0
1 0 1 0 1 1 1 0   0
1 0 1 0 1 1 1 1   0
1 0 1 1 0 0 0 0   1
1 0 1 1 0 0 0 1   1
1 0 1 1 0 0 1 0   1
1 0 1 1 0 0 1 1   1
1 0 1 1 0 1 0 0   0
1 0 1 1 0 1 0 1   0
1 0 1 1 0 1 1 0   0
1 0 1 1 0 1 1 1   0
1 0 1 1 1 0 0 0   0
1 0 1 1 1 0 0 1   0
1 0 1 1 1 0 1 0   0
1 0 1 1 1 0 1 1   0
1 0 1 1 1 1 0 0   0
1 0 1 1 1 1 0 1   0
1 0 1 1 1 1 1 0   0
1 0 1 1 1 1 1 1   0
1 1 0 0 0 0 0 0   0
1 1 0 0 0 0 0 1   0
1 1 0 0 0 0 1 0   1
1 1 0 0 0 0 1 1   0
1 1 0 0 0 1 0 0   0
1 1 0 0 0 1 0 1   0
1 1 0 0 0 1 1 0   0
1 1 0 0 0 1 1 1   0
1 1 0 0 1 0 0 0   1
1 1 0 0 1 0 0 1   0
1 1 0 0 1 0 1 0   1
1 1 0 0 1 0 1 1   0
1 1 0 0 1 1 0 0   1
1 1 0 0 1 1 0 1   0
1 1 0 0 1 1 1 0   1
1 1 0 0 1 1 1 1   0
1 1 0 1 0 0 0 0   1
1 1 0 1 0 0 0 1   0
1 1 0 1 0 0 1 0   1
1 1 0 1 0 0 1 1   0
1 1 0 1 0 1 0 0   1
1 1 0 1 0 1 0 1   0
1 1 0 1 0 1 1 0   1
1 1 0 1 0 1 1 1   0
1 1 0 1 1 0 0 0   0
1 1 0 1 1 0 0 1   0
1 1 0 1 1 0 1 0   0
1 1 0 1 1 0 1 1   0
1 1 0 1 1 1 0 0   0
1 1 0 1 1 1 0 1   0
1 1 0 1 1 1 1 0   0
1 1 0 1 1 1 1 1   0
1 1 1 0 0 0 0 0   0
1 1 1 0 0 0 0 1   0
1 1 1 0 0 0 1 0   0
1 1 1 0 0 0 1 1   0
1 1 1 0 0 1 0 0   0
1 1 1 0 0 1 0 1   0
1 1 1 0 0 1 1 0   0
1 1 1 0 0 1 1 1   0
1 1 1 0 1 0 0 0   0
1 1 1 0 1 0 0 1   0
1 1 1 0 1 0 1 0   0
1 1 1 0 1 0 1 1   0
1 1 1 0 1 1 0 0   0
1 1 1 0 1 1 0 1   0
1 1 1 0 1 1 1 0   0
1 1 1 0 1 1 1 1   0
1 1 1 1 0 0 0 0   1
1 1 1 1 0 0 0 1   1
1 1 1 1 0 0 1 0   1
1 1 1 1 0 0 1 1   1
1 1 1 1 0 1 0 0   1
1 1 1 1 0 1 0 1   1
1 1 1 1 0 1 1 0   1
1 1 1 1 0 1 1 1   1
1 1 1 1 1 0 0 0   1
1 1 1 1 1 0 0 1   1
1 1 1 1 1 0 1 0   1
1 1 1 1 1 0 1 1   1
1 1 1 1 1 1 0 0   1
1 1 1 1 1 1 0 1   1
1 1 1 1 1 1 1 0   1
1 1 1 1 1 1 1 1   1

Output ~FAST_LANGCARD_PAGE_Dx (DO4)

Truth table:

EXT_LANGCARD_SOFTSW (A7) LANGCARD_ACCESS_EN (A6) LA15 (A5) LA14 (A2) LA13 (A3) LA12 (A1)   ~FAST_LANGCARD_PAGE_Dx (DO4)
0 0 0 0 0 0   1
0 0 0 0 0 1   1
0 0 0 0 1 0   1
0 0 0 0 1 1   1
0 0 0 1 0 0   1
0 0 0 1 0 1   1
0 0 0 1 1 0   1
0 0 0 1 1 1   1
0 0 1 0 0 0   1
0 0 1 0 0 1   1
0 0 1 0 1 0   1
0 0 1 0 1 1   1
0 0 1 1 0 0   1
0 0 1 1 0 1   1
0 0 1 1 1 0   1
0 0 1 1 1 1   1
0 1 0 0 0 0   1
0 1 0 0 0 1   1
0 1 0 0 1 0   1
0 1 0 0 1 1   1
0 1 0 1 0 0   1
0 1 0 1 0 1   1
0 1 0 1 1 0   1
0 1 0 1 1 1   1
0 1 1 0 0 0   1
0 1 1 0 0 1   1
0 1 1 0 1 0   1
0 1 1 0 1 1   1
0 1 1 1 0 0   1
0 1 1 1 0 1   0
0 1 1 1 1 0   1
0 1 1 1 1 1   1
1 0 0 0 0 0   1
1 0 0 0 0 1   1
1 0 0 0 1 0   1
1 0 0 0 1 1   1
1 0 0 1 0 0   1
1 0 0 1 0 1   1
1 0 0 1 1 0   1
1 0 0 1 1 1   1
1 0 1 0 0 0   1
1 0 1 0 0 1   1
1 0 1 0 1 0   1
1 0 1 0 1 1   1
1 0 1 1 0 0   1
1 0 1 1 0 1   1
1 0 1 1 1 0   1
1 0 1 1 1 1   1
1 1 0 0 0 0   1
1 1 0 0 0 1   1
1 1 0 0 1 0   1
1 1 0 0 1 1   1
1 1 0 1 0 0   1
1 1 0 1 0 1   1
1 1 0 1 1 0   1
1 1 0 1 1 1   1
1 1 1 0 0 0   1
1 1 1 0 0 1   1
1 1 1 0 1 0   1
1 1 1 0 1 1   1
1 1 1 1 0 0   1
1 1 1 1 0 1   1
1 1 1 1 1 0   1
1 1 1 1 1 1   1