The gameport interface can't handle more than 4 buttons without any kind of trickery involving the additional axes. Furthermore, most DOS games don't natively support a joystick/gamepad with more than two axes.

Using JoyToKey (emulates keyboard and mouse input) and running these games within Windows 9x makes it more feasible.

Of course it doesn't handle more than 4 "fire buttons"...
Look, if you get a 1991 Gravis gamepad and open it up, what do you see underneath the
directional pad?
4 digital switches, exactly like the switches underneath the 4 face buttons, so you will call this trickery of the 1st and 2nd axis in the same way that you call buttons 5-8 trickery of the 3rd and 4th axis.

Kahenraz wrote on 2023-04-27, 16:07:

What is the difference between using two dedicated ports versus a Y cable? How can try joysticks work off of the same port?

Most games used a Y splitter if it supported 2 joysticks.
Instead of trying to track down a Y splitter, try looking for the Quickshot J-link, it functions as a 2p Y-splitter, but also gives you the convenience of front-mounted joyports.

In theory a second joyport could be added if it has its own i/o address configured via either jumpers or software and would allow 4 joysticks to be connected to a single PC.

Problem is, I can't think of any game that would allow this, my first guess would be micro machines 2 or some sports games supporting 3 or more players.
Since I don't have those games, I can't confirm if they do.

Vic Zarratt wrote on 2023-11-16, 23:09:

Of course it doesn't handle more than 4 "fire buttons"... Look, if you get a 1991 Gravis gamepad and open it up, what do you se […]
Show full quote

Of course it doesn't handle more than 4 "fire buttons"...
Look, if you get a 1991 Gravis gamepad and open it up, what do you see underneath the
directional pad?
4 digital switches, exactly like the switches underneath the 4 face buttons, so you will call this trickery of the 1st and 2nd axis in the same way that you call buttons 5-8 trickery of the 3rd and 4th axis.

Yep, the D-pad buttons are usually digital and that was possible to implement in PC gamepads since the analog nature of the axes were barely taken advantage of.

Gmlb256 wrote on 2023-11-16, 23:25:

Vic Zarratt wrote on 2023-11-16, 23:09:

Of course it doesn't handle more than 4 "fire buttons"... Look, if you get a 1991 Gravis gamepad and open it up, what do you se […]
Show full quote

Of course it doesn't handle more than 4 "fire buttons"...
Look, if you get a 1991 Gravis gamepad and open it up, what do you see underneath the
directional pad?
4 digital switches, exactly like the switches underneath the 4 face buttons, so you will call this trickery of the 1st and 2nd axis in the same way that you call buttons 5-8 trickery of the 3rd and 4th axis.

Yep, the D-pad buttons are usually digital and that was possible to implement in PC gamepads since the analog nature of the axes were barely taken advantage of.

Which means the gameport natively has 12 inputs.

Just because left and right, up and down are implemented as buttons. doesn't mean nor imply that they are read as buttons.

Given the analog nature of the X & Y axis inputs, a nice amount of buttons could be implemented. It wouldn't make them digital, though it would certainly seem that way to a layman.

weedeewee wrote on 2023-11-16, 23:52:

Just because left and right, up and down are implemented as buttons. doesn't mean nor imply that they are read as buttons.

Play street fighter 2 turbo or megaman X with a 6button pad and say that again for the 5th and 6th buttons.

weedeewee wrote on 2023-11-16, 23:52:

Given the analog nature of the X & Y axis inputs, a nice amount of buttons could be implemented. It wouldn't make them digital, though it would certainly seem that way to a layman.

1. Those who are new to the dos gaming scene are more likely to be laymen in knowledge than not, and it is those for whom I'm trying to explain this to.
2. Nice theory, if it didn't create a convoluted mess of a calibration menu if a game were to use such an idea.
By the time we needed more buttons than 8, USB was king.

The fact is that one DA15 pc gameport connector has only 8 inputs, four analog, and four digital.

weedeewee wrote on 2023-11-17, 01:16:

The fact is that one DA15 pc gameport connector has only 8 inputs, four analog, and four digital.

Yes that is accurate in terms of describing the science behind the gameport, though such a statement doesn't translate well to the noobs/laymen/console retro gamers coming into the Dos scene who might ask something like:
"Hey, I got a logic3 PC swiftpad, any way I can get the strafing shoulder keys to work with game X?"
It doesnt translate well, really it doesn't.

weedeewee wrote on 2023-11-17, 01:16:

The fact is that one DA15 pc gameport connector has only 8 inputs, four analog, and four digital.

This is 100% clear to me.

Gamepads and joysticks which support more complicated layouts require special support and use the pins for their own unique protocol.

I guess that, despite already having parallel and serial ports, the game port was designed to provide as much flexibility as possible for interacting with games as cheaply as possible. Analog potentiometers instead of logic controllers, for example.

Vic Zarratt wrote on 2023-11-16, 23:19:

Most games used a Y splitter if it supported 2 joysticks. Instead of trying to track down a Y splitter, try looking for the Quic […]
Show full quote

Kahenraz wrote on 2023-04-27, 16:07:

What is the difference between using two dedicated ports versus a Y cable? How can try joysticks work off of the same port?

Most games used a Y splitter if it supported 2 joysticks.
Instead of trying to track down a Y splitter, try looking for the Quickshot J-link, it functions as a 2p Y-splitter, but also gives you the convenience of front-mounted joyports.

In theory a second joyport could be added if it has its own i/o address configured via either jumpers or software and would allow 4 joysticks to be connected to a single PC.

Problem is, I can't think of any game that would allow this, my first guess would be micro machines 2 or some sports games supporting 3 or more players.
Since I don't have those games, I can't confirm if they do.

There's this radioshack thing to look out for too Re: Bought these (retro) hardware today seen in the pics there, blue on black. That will take 2 sticks plugged in, let you select stick one or stick two as the sole stick or 3rd setting is Y splitter for them both.

Hi everyone, I think the root cause is that the IBM Game Control Adapter™ was meant to be versatile.

Originally, maybe, there was a need to replicate paddle support, like with pong consoles.

The C64 had X/Y inputs (via SID), too, for that purpose same (paddle support). They were later repurposed to interfaces mouses, err, mice.

On the original IBM gameport card, there's a provision for custom circuits:
At the end of the card, there's a veroboard-like section..

Edit: There's another version with a provision for a second DE15 port.

I'm just mentioning this, because the gameport was the #1 experimental port of my childhood (QB45, VB1 on Windows, Turbo Pascal etc). 🙂

Out of all ports, it was the most plug&play type one. You could remove/add cables on the fly to it without worrying.

Because, the buttons were just switches anyway and the X/Y axises were meant to see varying resistance/conductivity.

This meant that almost everything from zero to max was being accepted on the inputs.

A short (buttons) or sudden power/voltage spike (axes) was essentially part of the design.

It's really cool to see a little breadboard section on the back of the PCB. Was this a retail card?