ATARI 8-bit / MSX Trackball

Por djh1697

Paragon (1702)

imagem de djh1697

16-06-2022, 22:36

Can anyone tell me if these are compatible, please?
They are both 9 pin connectors, the Atari has a switch for Joystick or Trackball, but is the trackball MSX compatible? I doubt the two buttons will work independently? I have limited desk space so an MSX mouse is a little impractical

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Por Pokun

Expert (72)

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17-06-2022, 01:53

I doubt they are since Atari systems has analog inputs used for things like paddles and mice while the MSX has all-digital inputs in the joystick ports and the A/D-conversions happens in the device itself.

Besides the GND pin is 9 on MSX instead of 8 like on Atari, which I guess means any active device (like a trackball) wouldn't work correctly and could possibly damage the MSX and/or the input device itself.

Por gdx

Enlighted (6215)

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17-06-2022, 02:05

Yes, Atari machines does not have strobe signal on pin 8 so not all serial devices are compatible. I too have been looking for a trackball for a long time but they are too expensive to me.

Por mohai

Paladin (1007)

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17-06-2022, 17:43

As far as I know, analog inputs in Atari connectors are only for analog paddles.
Mices are digital, AFAIK. See this to have an idea of the pinout used.
The main problem is that Atari 8 bit mice do output coordinates in a different way than the MSX ones.
MSX mouse outputs horizontal coordinate or vertical coordinate, depending on the state of pin 8.
Atari mouse outputs horizontal and vertical coordinates at the same time, in a kind of serial protocol, AFAIK.
Also, the pinout in the connector is slightly different. Do not connect one to any MSX, because you can damage it.

Maybe you could hack one of these and make it MSX compatible, someway. I do not know Atari mouse internals. They are somewhere in the net.

Por Pokun

Expert (72)

imagem de Pokun

18-06-2022, 00:17

I see.

I've played with the thought of taking one of those Atari arcade trackballs used in arcade systems like Missile Command and Marble Madness as well as in Neo Geo and some newer golf games. They are now branded Suzo-Happ but are still manufactured today and uses the same basic Atari design (I heard Atari licensed the design to Happ or something). They should be much better for things like games than those modern trackballs used as an alternative to a mouse.

Arcade trackballs has a 6 pin molex connector with +5V, GND, H-phase 1, H-phase 2, V-phase 1, V-phase 2 and a separate chassis-ground cable.
The MSX databook only shows an example how to build a paddle though, and not a mouse or trackball. People have built MSX mice but the MSX trackball is supposedly built differently from the MSX mouse for some reason.

Por Pokun

Expert (72)

imagem de Pokun

18-06-2022, 14:19

There is a datasheet on the Sony's GB-7 variant of HAL's trackball, which I suppose uses the same parts.
So it uses two ICs: LM339 quad differential comparator and something called "M60226" which I can't find any info about. A custom chip? What a bummer.