Expansion bus slots (50-pin IDC)
Contents |
Description
Several expansion bus connectors exist on MSX. These type of connectors were especially prevalent on early MSX1 models. The MSX standard does not specify the shape or pin-out of these connectors. The most common type is the 50-pin IDC connector (standard 2.54mm pitch) with one or two polarizing key. Pins are generally more or less the same as a cartridge slot.
Very few devices exist to connect to most of these connectors. But they can often be modified to accept standard MSX cartridges. An example of such a conversion from Expansion bus to MSX Cartridge slot can be found here.
Note: The pin numbers used for this page are those that correspond to the pin numbers for a cartridge slot.
50-pin IDC connectors
Connector with one polarizing key
| Computer model | Pin-out |
|---|---|
| AVT FC-200 | Even |
| Fenner SPC-800 | Odd |
| Goldstar FC-80, FC-80U, FC-200, GFC-1080, GFC-1080A | Even |
| Gradiente Expert GPC-1, Expert XP-800 | Odd |
| Mini IQ-3000 (OCM) | |
| Samsung SPC-800 | Odd |
| Spectravideo SVI-728 | Even |
| Vestel FC-200 | Even |
Connector with two polarizing keys
NOTE!
The corresponding female/male connector for this type is very hard to find nowday. As such you have two options, either modify the Expansion Bus port on the MSX to accept a single polarizing key IDC connector, or remove the polarizing key on the female IDC connector. The later is easier and avoids modifying the MSX, but it has the risk of allowing the IDC connector to be inserted the wrong way around.
| Computer model | Pin-out |
|---|---|
| AVT DPC-200, CPC-300 | Odd |
| Bawareth Perfect MSX1, Perfect MSX2 | Odd |
| CE-TEC MPC-80 | Odd |
| Daewoo CPC-88, CPC-200, CPC-300, CPC-300E, CPC-330K, CPC-400, CPC-400S, DPC-100, DPC-180, DPC-200 | Odd |
| Dynadata DPC-200 | Odd |
| Fenner DPC-200 | Odd |
| In Tensai DPC-200CD | Odd |
| Network DPC-200 | Odd |
| Olympia DPC-200, PHC-2 | Odd |
| Olympia PHC-28 | Even |
| Sanyo MPC-6, MPC-10, MPC-10mkII, MPC-11, MPC-100, PHC-28S, PHC-30 | Even |
| Sony HB-55, HB-75 (I/O bus on the Japanese models) | Specific |
| Talent DPC-200, DPC-200A, DPS-201, DPC-300, TPC-310, TPP-311, TPS-312 | Odd |
| Toshiba HX-10 series | Odd |
| Wandy DPC-200, CPC-300 | Odd |
| Yeno DPC-64 | Odd |
Pinout
The below table lists the Pin-out of the BUS connector with even-numbered pins to the polarizing key side. This corresponds to that of a regular MSX Cartridge port.
| Pin | Name | Type | Description |
|---|---|---|---|
| 1 | CS1 | O | ROM addresses 4000-7FFF select signal |
| 2 | CS2 | O | ROM addresses 8000-BFFF select signal |
| 3 | CS12 | O | ROM addresses 4000-BFFF select signal (for 256k ROM) |
| 4 | SLTSL | O | Slot select signal |
| 5 | RSV (N.C) | Reserved signal line - use inhibited | |
| 6 | RFSH | O | Refresh cycle signal |
| 7 | WAIT | I | CPU's WAIT request signal |
| 8 | INT | I | Interrupt request signal to CPU |
| 9 | M1 | O | Signal expressing CPU fetch cycle |
| 10 | BUSDIR | I | This signal controls direction of external databus buffer Cartridges are selected and L level is output from each cartridge at data transmission time |
| 11 | IORQ | O | I/O request signal |
| 12 | MERQ | O | Memory request signal |
| 13 | WR | O | Write timing signal |
| 14 | RD | O | Read timing signal |
| 15 | RESET | O | System reset signal |
| 16 | RSV (N.C) | Reserved signal line - use inhibited Note: According to its service manual, Goldstar FC-200 has composite video signal on this pin | |
| 17 | A9 | O | Address bus signals |
| 18 | A15 | O | Address bus signals |
| 19 | A11 | O | Address bus signals |
| 20 | A10 | O | Address bus signals |
| 21 | A7 | O | Address bus signals |
| 22 | A6 | O | Address bus signals |
| 23 | A12 | O | Address bus signals |
| 24 | A8 | O | Address bus signals |
| 25 | A14 | O | Address bus signals |
| 26 | A13 | O | Address bus signals |
| 27 | A1 | O | Address bus signals |
| 28 | A0 | O | Address bus signals |
| 29 | A3 | O | Address bus signals |
| 30 | A2 | O | Address bus signals |
| 31 | A5 | O | Address bus signals |
| 32 | A4 | O | Address bus signals |
| 33 | D1 | I/O | Data bus signals |
| 34 | D0 | I/O | Data bus signals |
| 35 | D3 | I/O | Data bus signals |
| 36 | D2 | I/O | Data bus signals |
| 37 | D5 | I/O | Data bus signals |
| 38 | D4 | I/O | Data bus signals |
| 39 | D7 | I/O | Data bus signals |
| 40 | D6 | I/O | Data bus signals |
| 41 | GND | PWR | Signal ground |
| 42 | CLOCK | O | CPU clock 3.579545MHz |
| 43 | GND | PWR | Signal ground |
| 44 | SW1 | For insertion/removal protect | |
| 45 | +5V | PWR | +5V power source |
| 46 | SW2 | For insertion/removal protect | |
| 47 | +5V | PWR | +5V power source |
| 48 | +12V | PWR | +12V power source |
| 49 | SOUNDIN | I | Sound input signal (-5bdm) |
| 50 | -12V | PWR | -12V power source |
Notes:
- On some manufacturers, even<->odd pin signal is swapped. Other pinouts might exist (not verified)
- Signals are TTL compatible.
- Power source +5V must be 300mA max per slot.
- Power source -/+12V must be 50mA max for all slots. Not connected on several MSXs.
- SOUNDIN pin is not connected on several MSXs (Eg Toshiba HX-10DP).
Other expansion bus
- Casio Expansion Bus Connector (for its dock)
- Frael Bruc 100 rev.1 Expansion Bus Connector (60-pin IDC)
- Fujitsu Module Slot Connector
- Mitsubishi ML-G10 I/O port expansion bus (60-pin IDC)
- Mitsubishi ML-G30 expansion unit connector
- National expansion Slot Connector
- Victor 96-PIN Slot Connector
- Yamaha Expansion Bus Connector
- Yamaha Mini-Cartridge Slot
- Yamaha Module Slot Connector
Links
- Connector with two polarizing keys datasheet (Infinite electronic)