MV2F: Difference between revisions

From NeoGeo Development Wiki
Jump to navigation Jump to search
mNo edit summary
Line 161: Line 161:

Multiplexer slot selection from [[NEO-F0]] and /OE from NEO-D0 to NEO-257.
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).

{| class="wikitable"
{| class="wikitable"
Line 173: Line 173:
|SLOTA(39) || SELECT(17)
|SLOTA(39) || SELECT(17)
{| class="wikitable"
|74HC259 || NEO-257
|Q5(10) || Y8~Y15 OE(35)

Revision as of 02:44, 6 May 2012

Revised 2 slot board with the second generation chipset.


todo: formatting, maybe pics


todo. Pair of NEO-257 on far left of board used for this? 32 bits per slot multiplexed to NEO-ZMC2?


todo. 16bits of input for FIXD0~FIXD7 to some NEO-257?

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
74HC259 NEO-257
Q5(10) Y8~Y15 OE(35)

NEO-D0 signals for Z80 reads are also buffered through NEO-E0 @ K10.

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)