Master System Cartridge
Same pinout also for Master System Expansion port, but upside down.
Korean and Japanese Master System uses different connector.
Front 2 50 ============== (at Cartridge) Back 1 49
Cartridge Back 39 1 ============== (at Console) Front 50 2
|5||/EXM1||(/M0-7) Memory 8000-BFFF|
|11||/EXM2||(/M8-B) Memory 0000-7FFF|
|13||/CE||Cartridge Output Enable|
|34||/CONT||A general-purpose input bit that can be read from port $dd bit5|
|37||/M1||Indicate machine cycle|
|43||JyDs||(also known as /KILLGA) Dissable joystick registers in IO space|
|45||/BUSACK||Bus request acknowledge|
|48||/JREAD||Active when access to joystick register region ($c0-$ff) in IO space|
|49||/CSRAM||(/MC-F) Memory C000-FFFF|
|50||?||/NMI||Non Maskable Interrupt|
Note: Direction is Console relative Cartridge
- Japanese and South Korean consoles use 44-pin cartridges, same shape as Mark I and Mark II
- All other consoles use 50-pin cartridges with a different shape
- The difference in cartridge style is a form of regional lockout
Cartridges were originally used for game of higher capacity than 256Kb (32KB), smaller ones were stored on cards.
When the Master System II arrived (without a card input), some Card games have been converted to cartridges.
Cartridges bigger than 512Kb (64KB) cannot be used with the 16 address bits and must use FCRs (Frame Control Registers, a bank switching method).
Because cards only have 15 address bits (while cartridges have all the 16 bits) and don't use bank switching, they are limited to 256Kb (32KB), cartridges are used for higher capacities.
- These are the signal directions you should adhere to, it may be possible to write towards console by using the Bus request mechanism of the Z80. Doing so will let you see only the Internal SRAM, Bios ROM is dissabled normaly via Register. With an I/O Request it may be possible to gain controll over the hardware on the IO Bus, but thats not so simple aswell.
- If you would like to make something like a ram patcher, better intercept the NMI somehow and do it by software afterwards.