WiModem makes joystick down = fire

[ral-clan]

Hi, I have one of Jim Drew's Wimodem's plugged into my VIC-20's user port. It works great, and I usually leave it installed all the time.

However, today (after over a year of having the WiModem), I noticed that when playing a joystick game (any game) when I press DOWN on the joystick, sometimes the game will register that as both a DOWN and FIRE. So the character on screen with move down and shoot at the same time.

Any ideas why this is happening. I've ruled out any other peripherals, it definitely only happens when the WiModem is plugged in.

[srowe]

I can't find a schematic for the WiModem but this picture

https://i1.wp.com/blog.hpz.pw/wp-conten ... 66-1-1.jpg

shows that user port pins 5, 6 and 7 are connected to the microcontroller. These pins are joy down, left and fire respectively.

[srowe]

Assuming this is it

https://www.c64-wiki.de/images/thumb/0/ ... 66save.jpg

it appears that pin 7 is attached to the Tx pin of the microcontroller, as well as the usual B & C pins.

I'm guessing this is how baud rates above 2400 are supported.

[ral-clan]

Here is the reponse I got from Jim Drew regarding this issue:

With the VIC-20, 3 of the joystick lines are connected to the USER PORT. 2 of those are connected to
the WiModem, so it could be that it interferes with the joystick operation. You would probably have
to remove it from the VIC-20 while using a joystick. This issue doesn't exist with the C64 or PET
because the joystick lines are not present on the USER PORT of those machines.

[RobertBe]

Hmm, I wonder if the same problem occurs with the Wi-Fi 64 modem from SharewarePlus or with the StrikeLink wi-fi modem. I will have to do some testing.

Truly,
Robert Bernardo
April 27-28 Commodore Los Angeles Super Show - http://www.portcommodore.com/class
June 8-9 Pacific Commodore Expo NW - http://www.portcommodore.com/pacommex
August 10-11 Commodore Vegas Expo v15 - http://www.portcommodore.com/commvex

[ral-clan]

Also, as previously noted by myself and another Denial member, if you start up the VIC with a WiModem and Mega-Cart installed, the Mega-Cart behaves as if two fire button presses had occurred. The menu clicks into the first choice "Cartridge Games" then selects "A World at War", the first game in the list and starts it.

This behaviour only happens from a cold boot. Warm booting the computer (I have a reset button installed) starts the Mega-Cart normally.