Time to modernize the TI-99/4A Joystick

[slinkeey]

disabling the chip and pushing a connector over it

?

[Tursi]

Because the 9901 is soldered to the board, and is a large IC, it is difficult to remove. But a replacement mod could be done by cutting a trace or two and disabling the 9901, then attaching a new one via connector or socket overtop of it.

 

I wanted to integrate my keyboard controller into a new 9901. But, I don't think it's a project I will take on.

[Omega-TI]

...who cares if it takes 4 years to put something together.

 

Gawd! I could NEVER wait four years! I think the simplest solution is going to be the route I take. I'll just make a joystick with TWO CONNECTORS. The first connector will use the standard joystick port, the second connector will tie into the keyboard matrix with the connector mounted on the back of the console. I figure I'll need 7 lines for the extra buttons (1,2,3,space, enter and P for pause). Seven buttons (including fire on the joystick port) are enough I think.

 

The beauty of this approach is that it'll be 100% compatible with all existing programs without the need for additional hardware or software . This approach is so simple anyone could probably do it. And I'll not have to wait four years, just until the Fall or Winter.

 

[Gary from OPA]

Gawd! I could NEVER wait four years! I think the simplest solution is going to be the route I take. I'll just make a joystick with TWO CONNECTORS. The first connector will use the standard joystick port, the second connector will tie into the keyboard matrix with the connector mounted on the back of the console. I figure I'll need 7 lines for the extra buttons (1,2,3,space, enter and P for pause). Seven buttons (including fire on the joystick port) are enough I think.

 

The beauty of this approach is that it'll be 100% compatible with all existing programs without the need for additional hardware or software . This approach is so simple anyone could probably do it. And I'll not have to wait four years, just until the Fall or Winter.

 

Good idea, I would include one more line the 'other number row' as least then you have FCTN-9 (BACK) and FCTN-8 (REDO) which alot of games use, at game over acreens, or include the two lines to allow for Y and N, which would also give you the + and - (used in the Atarisoft modules)

 

One question why the 3? -- Is not 1 and 2 enough for most games.

Edited May 28, 2014 by Gary from OPA

[Omega-TI]

Good idea, I would include one more line the 'other number row' as least then you have FCTN-9 (BACK) and FCTN-8 (REDO) which alot of games use, at game over acreens, or include the two lines to allow for Y and N, which would also give you the + and - (used in the Atarisoft modules)

 

One question why the 3? -- Is not 1 and 2 enough for most games.

 

Good idea! I was not thinking about the Atarisoft games. I had sort of planned to use the same type of connector that the joystick port uses, which would limit me to 9 nines. Hmmmmm.

 

The number 3 is used by only one game that I play, and that is Parsec for "Lift 3". It's actually Parsec and all the ships I've lost from trying to get to the keyboard in time that inspired this project.

[+Lee Stewart]

 

Gawd! I could NEVER wait four years! I think the simplest solution is going to be the route I take. I'll just make a joystick with TWO CONNECTORS. The first connector will use the standard joystick port, the second connector will tie into the keyboard matrix with the connector mounted on the back of the console. I figure I'll need 7 lines for the extra buttons (1,2,3,space, enter and P for pause). Seven buttons (including fire on the joystick port) are enough I think.

 

The beauty of this approach is that it'll be 100% compatible with all existing programs without the need for additional hardware or software . This approach is so simple anyone could probably do it. And I'll not have to wait four years, just until the Fall or Winter.

 

Why not just take all 15 lines out to a connector—you don't have to use them all for a given joy-port project and they would be available for other keyboard projects. Two easy variations on 15-pin connectors out there I can think of off the top of my head are the old 2-row DB-15 PC joystick connectors and the 3-row DB-15 VGA connectors.

 

...lee

[Omega-TI]

 

Why not just take all 15 lines out to a connector—you don't have to use them all for a given joy-port project and they would be available for other keyboard projects. Two easy variations on 15-pin connectors out there I can think of off the top of my head are the old 2-row DB-15 PC joystick connectors and the 3-row DB-15 VGA connectors.

 

...lee

 

Yep, probably what I'll do. I found the connector << HERE>> really cheap! I also found a 50" cable with connectors that I can easily chop up. << HERE >> When the time comes, finding the parts will be easy, except for the keyboard interface. I would like to find some sort of Y-Adapter pre-made for the keyboard connector, otherwise I'll end up soldering directly to the keyboard and that will look 'messy'. I think I'd rather go with the VGA type DB15 because it's smaller.

[slinkeey]

Yep, probably what I'll do. I found the connector << HERE>> really cheap! I also found a 50" cable with connectors that I can easily chop up. << HERE

 

The cable and the port are both male. I'm confused. Shouldn't they be opposites?

[+Lee Stewart]

Yep, probably what I'll do. I found the connector << HERE>> really cheap! I also found a 50" cable with connectors that I can easily chop up. << HERE >> When the time comes, finding the parts will be easy, except for the keyboard interface. I would like to find some sort of Y-Adapter pre-made for the keyboard connector, otherwise I'll end up soldering directly to the keyboard and that will look 'messy'. I think I'd rather go with the VGA type DB15 because it's smaller.

 

You do realize that those cable connectors will not mate with that panel-mounted connector, don't you? That said, it is a really good idea to use the male panel-mounted connector to minimize the likelihood of accidentally plugging a monitor cable into it! But, an inexpensive female-to-female VGA cable will probably be harder to find.

 

...lee

[Omega-TI]

 

You do realize that those cable connectors will not mate with that panel-mounted connector, don't you? That said, it is a really good idea to use the male panel-mounted connector to minimize the likelihood of accidentally plugging a monitor cable into it! But, an inexpensive female-to-female VGA cable will probably be harder to find.

 

...lee

 

I noticed that AFTER I posted the message... but they make these when all else in unobtanium...

 

I still have a few months before the weather gets bad again and I have time for the project. In that time I think I'll be able to think everything through, source all the parts and eliminate the need for the $1.50 gender changer.

[slinkeey]

I know that they make those, but I prefer to keep connections to a min.

Edited May 28, 2014 by slinkeey

[Omega-TI]

I know that they make those, but I prefer to keep connections to a min.

 

Me too, I'll probably end up getting a cable like << THIS >> and hacking one end off.

It's going to be a $pendy Ba$tard by the time it's done.

[slinkeey]

What's interesting is that you can get Joystick Shields for the arduino.

[sikotik]

I thought this would be a reasonably challenging first project so I did it.

 

I should have implemented switches to switch the wiring from joystick 1 to joystick 2, but I had planned on building 2 units from the start.

 

The only soldering on the console that was required was jumper wires from pin 2 and 7 on the joystick port.

 

 

[SkyPilot]

@sikotik Nice!  Will you be taking orders?

[sikotik]

@SkyPilot I ran myself and my limited budget into the ground making those two.  When I get a chance to clean up my documentation I'll share the board design and parts list. The hardest part was making the cabling. I suck at crimping Dupont connectors and soldering the wires onto the VGA connectors was no picnic either.

[Duewester]

Very nice and very similar. I suspect we both started from the same STL😀

https://www.thingiverse.com/thing:1481429

Mine is still a "work in progress".

And yes, soldering teensy tiny VGA wires is a PITB.

Edited February 13, 2023 by Duewester
clarify

[sikotik]

My original plan was to build a middle ground between the never released analog infrared controllers for the 99/4 and the painsticks we all know and "love" But then while I was looking for ideas I found this thread in the ColecoVision forum and decided I was going to make a similar arcade style stick instead.  I was even going to use some brushed aluminum on the top and sides of the enclosure but that was a few too many steps above my toolset and skill level. 

This is also Baby's first schematics and PCBS  Attached are the instructions, part list kicad files and an STL file for larger button caps. I'll never complain about unclear instructions ever again since I'm not sure I'm any better.

 

Joystick-w-keypad.zip