Shift Button Problem (I-PAC4)

[PiNPOiNT]

I used to have my machine up and running, but i recently re-wired everything and im all messed up again.

I'm having problems getting my IPAC/4 going with the shift button for player 3 and 4 (player 1 and 2 work fine)

here's how its setup

I have 4 player start buttons (player 1/2/3/4)
and i have a shift button (yellow)
and i want to have each player button be the mame start button (1/2/3/4)
and the shift function of each of them to be the player coin buttons (5/6/7/8)

in WinIPAC, i have each button assigned to a spot on the IPAC (start 1/start2/start3/start4)

and the shift button is assigned to player 1 sw 8 (which it is connected to on the IPAC)

so.

When i push the player 1 and 2 buttons, it fires off start 1 and start 2, and when i hold shift and press them, it gives me the shifted function of each. (good so far)

However when i push player 3 start it with only actually give me a 3 maybe 7 out of 10 times in a row, and other times it either wont do anything, or it will give me the shifted player 3 start button (7)  even though im not holding down shift.

At first i thought it was a crossed wire somewhere, but i've re-hooked it up several times. 

So, few questions....

1. Should (Shift 2) in WINIPAC be assigned to the same shift button as Shift 1 is?  eg: player 1 sw 8?

2. What else could account for the strange behavior on player 3 start?

I used to have it setup so that i only had to use 1 shift button to access the shifts of all player buttons before, i dont have to have 2 different shift buttons do i?

Any other ideas?  thanks

[Tiger-Heli]

Stay with me, this will be tough to explain:

>1. Should (Shift 2) in WINIPAC be assigned to the same shift button as Shift 1 >is?  eg: player 1 sw 8?

I didn't think you could do this.  The I-PAC/4 is really more like two daisy-chained I-PAC/2's on the same board.  i.e., you can set a shift key from inputs 1-28 (P1 and P2) for these inputs and a shift key from inputs 29-56 for these inputs.

>2. What else could account for the strange behavior on player 3 start?

Dunno, I thought that sounded odd.

>I used to have it setup so that i only had to use 1 shift button to access the >shifts of all player buttons before, i dont have to have 2 different shift buttons >do i?

Maybe, two shift buttons would be easiest, but you could do the following (just a general example, other solutions would be possible):

Leave P1SW8 as the shift function.
Wire the Start 3 and Start 4 buttons to P2SW7 and P2SW8 inputs.
If necessary, wire the P2 Buttons 7 and 8 and I-PAC/4 Coin 3 and Coin 4 inputs.

Reprogram the I-PAC/4 as follows:

P2SW7 - "3" , Shifted 7
P2SW8 - "4", Shifted 8
Coin 3 - J
Coin 4 - L