Can a joypad be moded for the MSX?

Master (198)

11-06-2019, 15:22

Hi MSXers,
recently, I was learning MSX-basic and Z80 assembly, in addition, I'm looking to develop MSX peripherals or to modify existing non-MSX compatible hardware to make it compatible with MSX hardware...
and in line with that, I was looking at modifying an ATARI 7800 Joypad to work with the MSX which looks rather plausible, the construction is rather simple and straight forward, I was wondering if anybody did before, also can a serial joypad like that of the NES or Famicom be used in any capacity?
really excited to hear what you have

By meits

Scribe (6544)

11-06-2019, 16:08

Are Atari 7800 controllers compatible with Atari 2600 controllers? I do remember that in the early 90s I connected an MSX joypad to a 2600 and it just worked. Second button was off limits though.
If there's no autofire involved it's just a matter of pinout conversion which should probably be done on an adapterboard or in an extension cable. So you don't have to "destroy" your joypad.

By gdx

Enlighted (6221)

11-06-2019, 16:32

Ali6x944 wrote:

the construction is rather simple and straight forward

Yes look here: http://wiki.icomp.de/wiki/DB9-Joystick

Ali6x944 wrote:

the construction is rather simple and straight forward, I was wondering if anybody did before

Many people have already done it.

Ali6x944 wrote:

the NES or Famicom be used in any capacity?

Yes but reading data is done bit per bit. You will need to program a specific routine in machine language to use a NES controller.

By Danjovic

Champion (336)

12-06-2019, 04:40

You can read nes controller in basic using a trick
https://hackaday.io/project/27494-snes-gamepad-adapter-for-m...

By ali6x944

Master (198)

12-06-2019, 13:31

gdx wrote:

Yes but reading data is done bit per bit. You will need to program a specific routine in machine language to use a NES controller.

could it be done in MSX1 machines, in assembly?

gdx wrote:

Many people have already done it.

can you share a link with us?
---------------------------------------------------------------------------------------------------------------------------------------------------------
http://www.the-liberator.net/site-files/retro-games/hardware...
do I need to short the resistors on the trig1 and trig2 buttons?

Meits wrote:

Are Atari 7800 controllers compatible with Atari 2600 controllers? I do remember that in the early 90s I connected an MSX joypad to a 2600 and it just worked. Second button was off limits though.
If there's no autofire involved it's just a matter of pinout conversion which should probably be done on an adapter board or in an extension cable. So you don't have to "destroy" your joypad.

for me, I would like to permanently mod it, however looking at this form a collector point of view I can see the appeal for an adapter, and for compatibility:

WIKI wrote:

The Atari 7800 ProSystem, or simply the Atari 7800, is a home video game console officially released by the Atari Corporation in 1986.[3] It is almost fully backward-compatible with the Atari 2600, the first console to have backward compatibility without the use of additional modules. It was considered affordable at a price of US$140 (equivalent to $320 in 2018).

By NYYRIKKI

Enlighted (6067)

13-06-2019, 01:40

ali6x944 wrote:

do I need to short the resistors on the trig1 and trig2 buttons?

Do not... That will cause a short circuit...

Looking at the pics, I would say...

Before mod (BL034):
1 - Orange
2 - Yellow
3 - Red
4 - White

After mod:
1 - White
2 - Orange
3 - Joy Pin 7 (or N/C)
4 - N/C

Loose wires:
Yellow (GND)
Red (+5v)

By Danjovic

Champion (336)

13-06-2019, 03:28

The straightforward solution is to invert the signals from the buttons and that can be accomplished by a pair of NPN transistors.

Please check : https://hackaday.io/page/6326-atari-7800-joypad-to-msx-adapter

By gdx

Enlighted (6221)

13-06-2019, 11:29

According to the table in the link I gave above, to modify your Atari 7800 Joypad you must change the cable because there is no wire going to pin 4 (button 2).

You can use this cable by cutting the useless connector:
https://www.ebay.com/itm/New-Controller-extension-cable-for-...

Then connect wires like this:

By ali6x944

Master (198)

14-06-2019, 21:59

so far thanks to @Danjovic, @gdx, and @NYYRIKKI, we found a good number of permanent and code based ways to read or modify these joysticks:
@NYYRIKKI generic genesis joypad mod:
https://www.msx.org/wiki/How_to_get_joypad_very_cheap_for_MSX
@Danjovic Atari 7800 joypad to MSX Adapter:
https://hackaday.io/page/6326-atari-7800-joypad-to-msx-adapter
@Danjovic (S)NES gamepad adapter for MSX computers:
https://hackaday.io/project/27494-snes-gamepad-adapter-for-m...
@gdx great and thorough step-by-step method to -permanently modify- Atari 7800 joypad to MSX:
HERE :) :D

so we did:
1.snes joypad /possibly even famicom I joypad?? -in software-
2.atari 7800 joypad -in hardware-
3.genesis joypad -in hardware-
is there any other easy to hack joysticks to aim for?

By Grauw

Ascended (10772)

14-06-2019, 23:33

The Genesis joypad is pretty similar to MSX, and the mod also makes all 6 buttons available, so that’s pretty nice.

By gdx

Enlighted (6221)

15-06-2019, 14:45

Some info for two great solutions here:
- Sega Genesis adapter
- SNES controller/mouse adapter