Posted by Mark Thomas on September 17, 1999 at 17:05:38:
In Reply to: Daisy-chaining 2 Poweramps... (more) posted by BobDC on September 17, 1999 at 13:01:44:
Well, I've had some discussions with PowerRamp techs, and determined the following:
Each PowerRamp can buffer multiple simultaneous keystrokes and send them to the computer one at a time. However, with two PowerRamps, since each cannot tell when the other is sending keycodes, you may have a situation where both powerramps are sending keycodes and they interfere with each other (the signal gets garbled), thus causing the key "sticking" and other possible problems.
So, Act Labs doesn't recommend *playing games* with two chained PowerRamps, because the possibility of signal conflicts is high. But, there's no technical reason why you couldn't daisy-chain them (with one minor exception which I'll explain later). In fact the reason they provide a keyboard pass-through is because users will generally use one at a time, which is fine.
So, what does this mean for arcade control builders? In my opinion, it's good news indeed. What you can do is wire the Player 1 and Player 2 controls to the _same_ PowerRamp. Use the second PowerRamp for all the miscellaneous buttons like Start, Coin, ESC, etc. Normally, you wouldn't be pressing those buttons while heavily using the controls.
I've just ordered a pair of MITEs for my MAME cabinet... and you bet I'll be daisy-chaining them. BTW, the Mites are better for hacking than the PowerRamp joys IMHO. More inputs. So don't feel bad that the joys are discontinued.
There's another advantage I can think of to having both control sets wired to the same PowerRamp: the macro facility. With the flip of one switch, you can have both player's controls completely reprogrammed. I plan to have one switch setting that puts the Player 1 controls on the left AND the right, so for 1-player-at-a-time games, you can use either side! Two players can then sit still--no games of "musical barstools".
Now for the technical caution about daisy-chaining in general: every length of cable provides attenuation (resistance that can cause signal loss). The power provided by the keyboard port is generally small, so you need to keep cable lengths as short as possible. This could potentially cause problems if you have three items daisy-chained (like 2 ramps + keyboard). This depends on a lot of factors (the motherboard, length of the cables, etc) so you just have to try it. I plan to wire my two Mite boards together directly, instead of using the cable between them, so that should help. I'm hoping that'll allow me to plug in a keyboard (or IR receiver for cordless keyboard).
Hope that helps!
-Mark.