FM-Towns joystick | MSX Resource Center (ページ 2/2)

Enlighted (5498)

04-10-2020, 01:52

This diagram tells us nothing more than the photo above but this is sufficient to deduce that Shouder button is connected between ground and pin 8 of the joystick port. Pin 8 of the FM/towns joystick port can be set to output or input. By default, it is an input. On MSX, it's always an output.

By Danjovic

Master (216)

04-10-2020, 16:35

sd_snatcher wrote:

buharka wrote:

That's the only image I could find. Judging by the traces it connects VCC with GND?

From what I'm seeing Vcc doesn't seem to be used. But by elimination, that shoulder button connects the pin-8 of the joystick port to the GND.

This means that this FM-Towns controller should never be connected directly to the MSX without an adapter, or it can fry the PSG when the shoulder button is pressed.

A 470 Ohms resistor in series with the shoulder key should mitigate that problem and render the controller usable on both platforms.

By nitz76

Supporter (15)

31-01-2022, 19:00

Hi! I drew a little schematic that also shows the D-SUB9 pinout:

See it on the website at https://www.retronicdesign.com/en/
Cheers! :)