SLOT6 board
C ROM data
CR0~CR31 are multiplexed by 32 74LS251 8-to-1 data selectors. See Graphic glitches.
- K28: CR0
- K29: CR1
- K30: CR2
- J28: CR3
- J29: CR4
- J30: CR5
- H28: CR6
- H29: CR7
- H30: CR8
- G28: CR9
- G29: CR10
- G30: CR11
- F28: CR12
- F29: CR13
- F30: CR14
- E28: CR15
- E29: CR16
- E30: CR17
- D28: CR18
- D29: CR19
- K3: CR20
- K2: CR21
- J3: CR22
- J2: CR23
- H3: CR24
- H2: CR25
- G3: CR26
- G2: CR27
- G1: CR82
- F3: CR29
- F2: CR30
- F1: CR31
S ROM data
FIXD0~FIXD7 are multiplexed by 8 74LS251 8-to-1 data selectors. See Graphic glitches.
- E3: FIXD0
- E2: FIXD1
- D3: FIXD2
- D2: FIXD3
- D1: FIXD4
- C3: FIXD5
- C2: FIXD6
- C1: FIXD7
Blocks
Chip 1, 2 & 3: 74F244 68k address lines
Chip 4: 74LS244 68k ROMs control lines
Chip 5 & 6: 74LS245 68k data lines
Chip 7 & 8: 74LS244 P odd lines and clocks
Chip 9 & 10: 74LS245 P even lines, C/S address, P clocks
Chip 11 & 13: 74LS245 PCM-A ROM multiplexed bus 0~23
Note: it looks like SDRADx and sSDRADx are swapped on chip 11 schematic compared to real board.
Chip 12 & 14: 74LS245 PCM-B ROM multiplexed bus 0~11
Note: it looks like SDRADx and sSDRADx are swapped on chip 12 schematic compared to real board.
Chip 15: 74LS245 Z80 D0~D7
Chip 16: 74LS244 Z80 M1 ROM control lines
Chip 17 & 18: 74LS244 Z80 address lines
