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Great Hierophant
February 5th, 2009, 05:01 AM
Most Tandy 1000s have these DIN-style joystick ports. I do not believe they can be disabled. However, if you were to install a sound card into one of these systems, it would most likely have a standard DA-15 joystick port. Would the two joystick interfaces, which must sit at the same addresses, confuse programs or would a joystick be read correctly regardless of which port it was attached?

Trixter
February 5th, 2009, 09:46 AM
I believe when I tried this I got mangled data from the port because both joystick interfaces were reading/writing from/to it at the same time. That was over a decade ago, though, so you should try it to find out.

kb2syd
February 5th, 2009, 11:28 AM
Is it possible to reliably adapt a pc joystick to the Tandy interface? From Trixter's site:


The pinout for the 6-pin joystick connector is:

5 X 1
6
4 2
3

Where:

1 is Y-axis
2 is X-axis
3 is Ground (0V)
4 is Button 1
5 is +5V
6 is Button 2

The pinout for a standard joystick is:

--------------------------
\ 1 2 3 4 5 6 7 8 /
\ 9 10 11 12 13 14 15 /
----------------------

pin assignment
1 +5V
2 stick 1 button 1
3 stick 1 X-axis
4 ground (0V)
5 ground (0V)
6 stick 1 Y-axis
7 stick 1 button 2
8 +5V
9 +5V
10 stick 2 button 1
11 stick 2 X-axis
12 ground (0V)
13 stick 2 Y-axis
14 stick 2 button 2
15 +5V

Fallo
February 5th, 2009, 03:28 PM
I believe when I tried this I got mangled data from the port because both joystick interfaces were reading/writing from/to it at the same time. That was over a decade ago, though, so you should try it to find out.

Good question. I've heard that if you install a game port in a Tandy 1000, it may work some of the time, but it's not reliable. I think that you can disable the onboard game ports on the later 1000s (SL and up). You definitely cannot disable them on the earlier (90-key keyboard) models.

Oddly enough, I saw a Radio Shack joystick card on Ebay that looked just like Kraft joystick cards, sporting two game ports and a speed switch. This thing was a mystery. It likely was not intended for the Tandy 1000s. Maybe the 3000/4000/5000 line?

vwestlife
February 5th, 2009, 07:52 PM
Tandy joysticks are easy to find on eBay. TRS-80 Color Computer ("CoCo") joysticks can also be used; they are pin-compatible.

Great Hierophant
February 6th, 2009, 08:56 AM
I believe when I tried this I got mangled data from the port because both joystick interfaces were reading/writing from/to it at the same time. That was over a decade ago, though, so you should try it to find out.

I think you are right, especially about the reading. One joystick port will return a real value on a read, the other will probably return a value based on an open bus (the value you wrote.) This would lead to a bus conflict, so you would not get consistent read.

I think if you put a sound card into these Tandys, you have to disable its joystick port or the Tandy's to ensure proper joystick function (unless you are using the Tandy's sound DAC, which means you can't use a joystick at all.)