Happ Drive Board through Parallel Port

[twistedsymphony]

I was looking through a bunch of Operator Manuals for information related to more recent Sega Racers. I was surprised to see that the two Europa-R games that Sega made (GRID and Sega Rally 3) both used the HAPP Motor control board.

I know these were also used on Atomiswave Racers (Maximum Speed, and Faster Than Speed), but what interested me about their use on Europa-R is that it's PC based hardware unlike the Atomiswave which is Dreamcast based.

Looking at the wiring diagram they were running to the "25-Pin P/Port"... Surely, I thought, they're not using a Parallel Port to drive the force feedback board... Looking at other Sega PC hardware from the Era such as the Lindbergh and the RingEdge, none of them had parallel ports.

It took some digging to find a picture of the actual Europa-R hardware but sure enough, it's got a PCI Parallel card and that seems to be the only 25 pin connector on the Europa-R.

These boards are pretty cheap, you can still buy them new for about $100 and you can find them used for about $40 and they work with the pretty cheap and ubiquitous Happ motor. I've had one kicking around my parts shelf for a few years not sure what to do with it, it never occurred to me that it could be driven by the parallel port (mostly I'd assumed it'd be too slow). Now I'm thinking if it's good enough for arcade use, with the right software driver it could be a cheap and easy to source setup for those looking for an arcade quality force feedback setup at home.

[Howard_Casto]

That actually makes sense to me.  Our resident Sega expert, SailorSat, can probably explain better than I can, but many Sega games only used a single byte of data to control the force-feedback motor.  The parallel port has 8 I/O lines.... that's 8 bits combined to form a byte.  Couple that with the fact that  data can be pulsed and interleaved and you've got a lot to work with.  Also keep in mind that a parallel port can be used as a serial port when needed.   


Looking at the board you linked to, the controller board is only using 5 bits.  Direction for one bit (0 for left, 1 for right or vice-versa) and 4 input lines, which might work as strength multipliers, but I doubt it judging by the text about iso input text on the board.  Also it boasts fast PWM, which would allow for more analog levels of strength via strobing... which is exactly how we control our leds. 

Anyway, on first glance at least, I think the board can be removed from the equation and replaced with an AVR and an amp or motor controller to drive the motor.  It couldn't be doing anything all that complex.  I'm not familiar with the price of those components though so it might be simpler and cheaper to just order the board. 


*edit*

I should really read the description next time. 

It spells it out quite plainly that indeed one bit is for direction and the other 4 are for motor strength.  (aka torque).  We could build something like this quite easily. 

[twistedsymphony]

It spells it out quite plainly that indeed one bit is for direction and the other 4 are for motor strength.  (aka torque).  We could build something like this quite easily. 

Yup that's exactly how it works, the Happ Driver boards are extremely simple.

FWIW the generation BEFORE the Eruopa (Lindbergh) used a Serial 422 based protocol for the Drive boards and Model 3 up through everything before the Lindbergh (NAOMI/TriForce/Chihiro/Hikaru) all used MIDI for the Drive board communication.

The real irony is that the NAOMI has a Serial 422 port, but the Lindbergh does not so for the Lindbergh games they have a RS-232 to RS-422 serial adapter between the game board and the drive board.

[Howard_Casto]

There are examples out there of AVR srouce code that makes a device show up as a HID joystick.... some have dabbled into force feedback. 

So an Arduino with 5 lines and pwm capabilities would probably do it.  It could show up as a joystick for more modern pc games reading ff data and converting it to the motors 5 bits.  For sims, emulators and more homebrew stuff the bits could be passed directly via serial connection. 

It's absolutely possible to do it with just the parallel port, but I don't know of a virtual joystick program that has successfully faked force-feedback aside from the 360ce drivers. 

[SailorSat]

vJoy does, but writing a wrapper application is kinda pain in the ass.