Hall Effect?

[etumor]

Going through KLOV, I have run across the control type "Hall Effect" for a couple of games.  Specifically, I, Robot and Road Runner are both listed as using this kind of control.  It appears to be a joystick.

Can anybody explain what this was?

-Jeff

[Hoagie_one]

i believe its a positional joystick, where it knows the position of the sitck.

[ErikRuud]

The joysticks in those games were basically analog sticks.  They used a "Hall Effect" device instead of Potentiometers. (Pots).

A "Hall Effect" is an electronic chip that measures the strength of a magnetic field.  "Hall Effect" joysticks have a mgnet on the end of the shaft and "Hall Effect" sensors mounted where you normally find switches.

As you move the stick around the sensors were used to read the position of the magnet.

[RayB]

yeah, an over-engineered analog stick. :-D

[Kremmit]

Working Hall Effect sticks are hard to come by, and I dunno if anybody has ever come up with a way to interface 'em with MAME.  (anyone?)

An analog stick is an OK replacement, but most analog sticks don't usually have anywhere near the stiffness needed to "feel" right.  A 49 way stick is a better replacement.  49 way sticks can still be bought from Happs, or pulled from Sinistar, Bubbles, Arch Rivals, Blitz, or Guantlet 2 machines.   (any others?)

To use a 49 way with MAME, you could use one of these: http://dave.bit2000.com/sjc.html, or you could use Analog MAME + http://www.urebelscum.speedhost.com/index.html.

To use a 49 way in place of a Hall stick on an actual I, Robot or Road Runner PCB, try:  http://www.arcadecollecting.com/info/49way_to_Hall.gif.  (this is not MY schematic, don't ask me anything about it, I have never tried it)

[Minwah]

An analog stick is an OK replacement, but most analog sticks don't usually have anywhere near the stiffness needed to "feel" right.  A 49 way stick is a better replacement.  49 way sticks can still be bought from Happs, or pulled from Sinistar, Bubbles, Arch Rivals, Blitz, or Guantlet 2 machines.   (any others?)

So a 49-way feels more like a hall effect?  What about the lower resolution of the 49-way (compared to analog), does it matter?

[Kremmit]

So a 49-way feels more like a hall effect?  What about the lower resolution of the 49-way (compared to analog), does it matter?

A 49 way doesn'' feel "the same" as a Hall stick, any more than a Ms. Pac Man/Galaga reunion microswitch joystick feels the same as an original Ms. Pac leaf switch joystick.  But at least it feels like an arcade stick, instead of one of those super-loose PC sticks that aren't any good for anything except Flight Sims.  Plus, PC analog sticks always have those funky handgrips- I, Robot and Road Runner had a the black Atari logo Ball-top.  For these reasons, I feel the 49 way is the closest we are likely to get.  (unless somebody does know how to interface a Hall stick w/ MAME...)

I honestly don't know about the resolution - anybody know what resolution a Hall stick puts out?

[Minwah]

A 49 way doesn'' feel "the same" as a Hall stick, any more than a Ms. Pac Man/Galaga reunion microswitch joystick feels the same as an original Ms. Pac leaf switch joystick.  But at least it feels like an arcade stick, instead of one of those super-loose PC sticks that aren't any good for anything except Flight Sims.  Plus, PC analog sticks always have those funky handgrips- I, Robot and Road Runner had a the black Atari logo Ball-top.  For these reasons, I feel the 49 way is the closest we are likely to get.  (unless somebody does know how to interface a Hall stick w/ MAME...)

I honestly don't know about the resolution - anybody know what resolution a Hall stick puts out?

Ahh, sorry, what I was getting was: is a 49-way better for those games than an *arcade* analog stick.

I don't know the resolution of a hall effect stick, but it must be more or less the same as an analog stick (I guess 256x256ish matrix).  Since a 49-way only uses a 7x7 way matrix, I would have thought an anlog stick would be better.

I get what you're saying about PC analog sticks, but I happen to have an arcade analog stick

[etumor]

Okay, so hypothetically speaking, what else are 49-way joysticks good for?  Do they work on 8-way games (and when I say WORK, I mean do they FEEL RIGHT, or even close to it).  Are they a good fit for analog control games like Paperboy?

So far it sounds like it would be the "right" stick for Sinistar and Bubbles, and an okay stick for I, Robot.  I'm just wondering, if I put one on one of my cabinets, what else could it be used for (which would determine which cabinet I put it on and where it will go).

-Jeff

[Minwah]

Okay, so hypothetically speaking, what else are 49-way joysticks good for?  Do they work on 8-way games (and when I say WORK, I mean do they FEEL RIGHT, or even close to it).  Are they a good fit for analog control games like Paperboy?

So far it sounds like it would be the "right" stick for Sinistar and Bubbles, and an okay stick for I, Robot.  I'm just wondering, if I put one on one of my cabinets, what else could it be used for (which would determine which cabinet I put it on and where it will go).

There was a thread here a week or 2 ago about a similar topic...basically I think Paige was saying 49-ways are pretty good for 8-way games, not too good for 4-way.  Also it was guessed that they would be pretty good for analog stick games, although no-one had massively put the theory to test yet.

On paper it sounds to me like 49-ways wouldn't be too good for analog games...but in practice I doubt the old analog stick games took full advantage of the resolution of the sticks anyway (?)  U_Rebel made a great page here: http://www.urebelscum.speedhost.com/49waySticks.html

[u_rebelscum]

AFAIK, Atari Hall Effect outputs:

0 to 12+ volts (max),
~6+ volts centered.

I've seen three different looking hall PCBs, and maybe a fourth if it's not a digital hack.  For instance the I, Robot and Roadrunner manuals talk about calibrating the sticks differently: Roadrunner uses pots to center, I, Robot is automatic.  The Hall Effect pics I've seen at one of the arcade history web sites (don't remember which one) is way different then those pictured in the abov manuals.

AFAIK, there are no currently made 0 to 12 volt Hall Effect sensors any more.  They're all 0-5+ (or digital on/off) now.