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Address Buses
|
A1-A23
|
M68K Address Bus
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ZA0-ZA15
|
Z80 Address bus
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Data Buses
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D0-D15
|
M68K Data bus
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ZD0-ZD7
|
Z80 Data bus
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IO port lines
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EM1X
|
Port 1 lines
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EM2X
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Port 2 lines
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EM3X
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Port 3 lines
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Control lines
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M68K related control lines
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/BG
|
Bus Grant
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/BGACK
|
Bus Grand Acknowledge
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/BR
|
Bus Request
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FC0
|
Function Code 0, 1 = Accessing user data
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FC1
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Function Code 1, 1 = Accessing user program
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/HALT
|
Halt 68K execution
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/RESET
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Reset 68K
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/VPA
|
Valid Peripheral Access
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/AS
|
Address strobe
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/DTACK
|
Data Acknowledge
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/UDS
|
Accessing even bytes
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/LDS
|
Accessing odd bytes
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R/W
|
Read/Write pin, 0 = write 1 = read
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Z80 related control lines
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/ZM1
|
Opcode fetch strobe
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/ZRD
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Read strobe
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/ZWR
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Write strobe
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/ZMREQ
|
Memory request
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/ZIORQ
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IO request
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/ZNMI
|
Non-maskable IRQ
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/ZBR
|
Bus request
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/ZBAK
|
Bus Acknowledge
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/ZRES
|
Reset Z80
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/ZWAIT
|
Wait
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Address decoding related control lines
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/ASEL
|
Read or Write on $000000-$7FFFFF region
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/CAS0
|
Read or Write on $000000-$DFFFFF region
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/RAS0
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Read or Write on $E00000-$FFFFFF region, act as /CE signal for the RAM chips
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/CE0
|
Chip Enable for the cartridge, low when accessing $000000-$3FFFFF region when expension unit isn't inserted or $400000-$7FFFFF when it is.
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/TIME
|
Read or Write on $A13000-$A130FF region
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/LWR
|
Lower byte WRite
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/UWR
|
Upper byte WRite
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/NOE
|
/OE signal for the lower part of the RAM
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/EOE
|
/OE signal for the upper part of the RAM
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/ZREF
|
Unknown, tied to unused pin #1 of Z80 RAM
|
/ZRAM
|
/CE for the Z80 RAM
|
Configuration related control lines
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/DISK
|
0V Expansion Unit connected
|
FREQ
|
5V = 60Hz, 0V = 50Hz
|
/FRES
|
|
LANG
|
5V = English, 0V = Japanese
|
/M3
|
Mark III compatibility mode
|
VRAM related control lines
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/CAS1
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Column address strobe
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/RAS1
|
Row address strobe
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/SE0
|
Serial data bus /OE
|
SC
|
Serial clock
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/WE0
|
Write enable
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/OE1
|
Output enable
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Clock lines
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MCLK
|
Master Clock
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VCLK
|
68K clock
|
ZCLK
|
Z80 clock
|
EDCLK
|
Unknown clock
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