Joystick in user port

[vicassembly]

I seem to remember reading that an additional joystick could be added to the user port. Anyone else heard of such a thing? Through an RS232 connection?


Jonathan

[Boray]

That is a good idea. Should not be too hard to do.

[tokra]

This exists for the C64:

http://www.protovision-online.de/hardw/build4player.htm

and can be bought ready built:

http://www.vesalia.de/e_c64_4player.htm

On the Protovision site you can also find the source-code how to read the joystick-ports - no idea if this can be adapted to the VIC or if the User-Ports are even identical to support this

[Mayhem]

There was a joystick adapter released for the Vic20 by OEM, but I can't recall if it split the existing joystick port, or went in the user port.

[Jeff-20]

Ew! Sounds a little perverse. But I'll give it a try.

[Kananga]

The Protovision 4-player adapter works for the Vic-20 as well, because it uses the parallel port bits of the user port.
You can either buy or build it yourself, the schematics are available on the protovision site.
I built it some time ago and can now connect three joysticks to my Vic-20. Not that I found any use for it yet...

[eslapion]

AFAIK, there was a game published in Compute's Gazette for the VIC which required a second joystick attached to the User port.

Does anybody remember that?

On the Protovision site you can also find the source-code how to read the joystick-ports - no idea if this can be adapted to the VIC or if the User-Ports are even identical to support this

Modems for the VIC also work on the 64 and vice-versa. There is a certain similitude.

[GreyGhost]

In Compute, March 1983. The game is called Fighter Aces. Also, If you can find a copy of "Tricks for Vics" by Sam D. Roberts, the appendix has an article for adding two additional joysticks to the Vic via the user port.

[nbla000]

There was a joystick adapter released for the Vic20 by OEM, but I can't recall if it split the existing joystick port, or went in the user port.

It went in the user port and add an just one additional joystick, there are 4 cart games that uses this hardware, Close Encounters, Amazing Maze, Space Ric-o-shay and Tank Wars.

[vicassembly]

I ordered a copy of Tricks for Vics.... I think I may try it.

[rmelick]

For the Vesalia adapter, anyone know how to read the left port (looking top-down onto the unit)? I can read the right port (closest to the cassette connection looking top-down onto the unit) thusly:

Code: Select all

1 DA=37136:POKEDA,0
2 GOSUB10
3 PRINT"{CLR}J0 J1 J2 J3 FB"
4 PRINTJ0;J1;J2;J3;FB
5 GOTO2
10 P=PEEK(DA)
11 J2=-((PAND4)=0)
12 J3=-((PAND8)=0)
13 J0=-((PAND1)=0)
14 J1=-((PAND2)=0)
20 FB=-((PAND16)=0):RETURN

[Kananga]

The Protovision Adapter multiplexes the input for the ports. So you have to select the port first before reading.

The according bit of the port should be set to output mode (one time initialisation):

Code: Select all

POKE DA+2,128

Now select the port for reading:

First port:

Code: Select all

POKE DA, 0

Second port:

Code: Select all

POKE DA, 128

[rmelick]

This is great! Thank you!!

[e5frog]

If you only hook up one extra port you don't need any circuitry.

Perhaps a three player worm game would be a doable task on the VIC.

Here are some more examples of games if you haven't seen them already:
http://www.protovision-online.de/hardw/4_player.htm

Here are some code example, for the C64, in assembly:
http://www.protovision-online.de/hardw/ ... htm#codeit

When I wrote my 4 joystick tester program (on the C64) I made it in BASIC and it was a little slow. So perhaps you need to program that part in assembler to speed things up.

[rmelick]

Here are some more examples of games if you haven't seen them already:

Last night I wrote a special edition of my game with CB2 sound (see Programmer's Reference Guide, pg. 232) and Protovision 4-player interface support. To access these new features, plug your joystick into the outside Protovision port, hold down the fire button and LOAD/RUN the 'Assteroyd Dodger' program.

http://sleepingelephant.com/ipw-web/bul ... php?t=4861

This is the fastest version yet because reading the Protovision joystick requires two fewer steps in the main loop than the default port on the VIC-20.