1. The board will attach to PC video card (DB-15 VGA) and act as a pass through to monitor. Board can disable video signal output to monitor using a simple mux circuit . The board will detect the frequency of the incoming video signal. Only 3 frequency will be counted 15Khz, 25Khz, 31Khz all else will be blanked. These frequencies can be set by on board jumpers.
2. When the VGA signal is blanked, the board will output a video signal of its own at a pre-selected fixed frequency based on the above jumper. The output will be a simple color low res image or can be just text. Possible video output generator CLPD (Altera MAX II).
3. Board will connect to PC via USB. Board will be a HID keyboard device. Board will have 48 pulled up I/O lines. Each I/O line will be mapped to a character from a keyboard. When an I/O line is pulled low the finished board will send a character to the PC. PC thinks board is a keyboard. Each I/O will be connected to a mechanical switch so firmware will need to debounce each I/O line.
4. This device will be used in an arcade machine so button combinations will be frequent. A button press can not be missed. Traditional key scanning techniques may not work for this application. Handling of I/O, HID and USB can be done using a microcontroller CY7C63413 which seem to fit best since features are built into microcontroller. CY7C63413 can set all I/O on interrupts.
5. Board will work with one CY7C63413 for 24 I/O capability which provides enough I/O for JAMMA specification as noted below. This microcontroller will act as primary and will connect to PC. Second CY7C63413 microcontroller will talk to first using end point or other fast method to avoid latency in detecting I/O change and transmitting characters.
6. Board will have audio amp circuit. I will provide schematic for this.
7. Board will have I/O, Audioe , PWR, GND, VGA signals all? routed to PCB Screw Terminals and JAMMA interface. JAMMA is 56 pin edge connector. I will provide pinouts.
8. Board will have circuit for creating composite sync signal from separate VGA H / V signals. I will provide schematics. Circuit will be controller by jumper to turn off or on.
9. PS2 keyboard can be connected to board and be passed through to PC. CY7C63413 has built in features to support this.
No payment will be made until one pre-programmed part is provided for testing. Upon sucessful testing full payment will be made and coder will release full source code.