Revised 2 slot board with the second generation chipset.
Pinouts
todo: formatting, maybe pics
C ROM / LSPC2 / NEO-ZMC2
todo. Pair of NEO-257 on far left of board used for this? 32 bits per slot multiplexed to NEO-ZMC2?
S ROM / LSPC2 / NEO-B1
FIXD0~FIXD7 is multiplexed from each from by NEO-257 @ J9. Same one is used for Z80 D0~D7 for cart M1 access.
| NEO-257 |
CHA slot #1
|
| A0(4) |
FIXD0(B39)
|
| A1(6) |
FIXD1(B40)
|
| A2(13) |
FIXD2(B41)
|
| A3(15) |
FIXD3(B42)
|
| A4(19) |
FIXD4(B43)
|
| A5(21) |
FIXD5(B44)
|
| A6(29) |
FIXD6(B45)
|
| A7(31) |
FIXD7(B46)
|
| NEO-257 |
CHA slot #2
|
| B0(5) |
FIXD0(B39)
|
| B1(7) |
FIXD1(B40)
|
| B2(14) |
FIXD2(B41)
|
| B3(16) |
FIXD3(B42)
|
| B4(20) |
FIXD4(B43)
|
| B5(22) |
FIXD5(B44)
|
| B6(30) |
FIXD6(B45)
|
| B7(32) |
FIXD7(B46)
|
Selected FIX data is output to NEO-B1 from Y0~Y7.
| NEO-257 |
NEO-B1
|
| Y0(8) |
FIXD0(131)
|
| Y1(9) |
FIXD1(132)
|
| Y2(11) |
FIXD2(133)
|
| Y3(12) |
FIXD3(134)
|
| Y4(23) |
FIXD4(135)
|
| Y5(24) |
FIXD5(136)
|
| Y6(27) |
FIXD6(137)
|
| Y7(28) |
FIXD7(138)
|
The 257 seems to have common enable/select lines. See M ROM section for those as cart M ROM/S ROM are always enabled together.
V ROM / YM2610 access
todo. NEO-E0 for address outputs only, some NEO-G0 for the databuses?
P ROM / 68k access
todo. some NEO-G0 for D0~D15? NEO-E0 for A1~A23?
M ROM / Z80 access
Z80 A0~A15 is buffered through NEO-E0 @ K10 to SDA0~SDA15 of both cart slots.
| Z80 |
NEO-E0
|
| A0(30) |
A1(64)
|
| A1(31) |
A2(1)
|
| A2(32) |
A3(2)
|
| A3(33) |
A4(3)
|
| A4(34) |
A5(4)
|
| A5(35) |
A6(15)
|
| A6(36) |
A7(16)
|
| A7(37) |
A8(17)
|
| A8(38) |
A9(18)
|
| A9(39 |
A10(19)
|
| A10(40) |
A11(20)
|
| A11(1) |
A12(21)
|
| A12(2) |
A13(31)
|
| A13(3) |
A14(32)
|
| A14(4) |
A15(33)
|
| A15(5) |
A16(34)
|
| NEO-E0 |
CHA slot #1 & #2
|
| Y0(5) |
SDA0(A43)
|
| Y1(6) |
SDA1(A44)
|
| Y2(7) |
SDA2(A45)
|
| Y3(8) |
SDA3(A46)
|
| Y4(9) |
SDA4(A47)
|
| Y5(11) |
SDA5(A48)
|
| Y6(12) |
SDA6(A49)
|
| Y7(13) |
SDA7(A50)
|
| Y8(14) |
SDA8(A51)
|
| Y9(22) |
SDA9(A52)
|
| Y10(23) |
SDA10(A53)
|
| Y11(24) |
SDA11(A54)
|
| Y12(27) |
SDA12(A55)
|
| Y13(28) |
SDA13(A56)
|
| Y14(29) |
SDA14(A57)
|
| Y15(30) |
SDA15(A58)
|
Z80 D0~D7 is multiplexed from each slot by NEO-257 @ J9. No need for bidirectional D0~D7 since only reads can be done from cart.
| Z80 |
NEO-257
|
| D0(14) |
Y8(40)
|
| D1(15) |
Y9(41)
|
| D2(12) |
Y10(43)
|
| D3(8) |
Y11(44)
|
| D4(7) |
Y12(55)
|
| D5(9) |
Y13(56)
|
| D6(10) |
Y14(59)
|
| D7(13) |
Y15(60)
|
| NEO-257 |
CHA slot #1
|
| A8(36) |
CHA SDD0(B51)
|
| A9(38) |
CHA SDD1(B52)
|
| A10(45) |
CHA SDD2(B53)
|
| A11(47) |
CHA SDD3(B54)
|
| A12(51) |
CHA SDD4(B55)
|
| A13(53) |
CHA SDD5(B56)
|
| A14(62) |
CHA SDD6(B57)
|
| A15(64) |
CHA SDD7(B58)
|
| NEO-257 |
CHA slot #2
|
| B8(37) |
CHA SDD0(B51)
|
| B9(39) |
CHA SDD1(B52)
|
| B10(46) |
CHA SDD2(B53)
|
| B11(48) |
CHA SDD3(B54)
|
| B12(52) |
CHA SDD4(B55)
|
| B13(54) |
CHA SDD5(B56)
|
| B14(63) |
CHA SDD6(B57)
|
| B15(1) |
CHA SDD7(B58)
|
Multiplexer slot selection from NEO-F0, /OE from NEO-D0 and OE from 74HC259 to NEO-257. The 257 must only output to Z80 when it is trying to read ROM (NEO-D0) and the cart M1/S1 is selected (74HC259).
| NEO-D0 |
NEO-257
|
| SDROM(11) |
Y8~Y15 /OE(33)
|
| NEO-F0 |
NEO-257
|
| SLOTA(39) |
SELECT(17)
|
| 74HC259 |
NEO-257
|
| Q5(10) |
Y8~Y15 OE(35)
|
NEO-D0 signals for Z80 reads are also buffered through NEO-E0 @ K10.
| NEO-D0 |
NEO-E0
|
| SDMRD(39) |
A17(36)
|
| SDROM(11) |
A18(37)
|
| SDRD0(45) |
A19(38)
|
| SDRD1(46) |
A20(48)
|
| NEO-E0 |
CHA slot #1 & #2
|
| Y16(39) |
SDMRD(B50)
|
| Y17(40) |
SDROM(B49)
|
| Y18(41) |
SDRD0(B47)
|
| Y19(43) |
SDRD1(B48)
|