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- Newsgroups: comp.sys.ibm.pc.hardware
- Path: sparky!uunet!zaphod.mps.ohio-state.edu!caen!spool.mu.edu!agate!linus!alliant!mydual!olson
- From: olson@mydual.uucp (Kirtland H. Olson)
- Subject: CORRECTED Joystick Diagram and More Data
- Message-ID: <1992Dec18.013143.476@mydual.uucp>
- Keywords: CORRECTION JOYSTICK VALUES PINOUT
- Reply-To: olson%mydual.uucp@alliant.com
- Organization: The Harvard Group, 01451-0667
- References: <724450360.15021@minster.york.ac.uk> <1992Dec16.153527.7309@mydual.uucp>
- Date: Fri, 18 Dec 1992 01:31:43 GMT
- Lines: 77
-
- In article <1992Dec16.153527.7309@mydual.uucp> olson%mydual.uucp@alliant.com writes:
-
- >In article <724450360.15021@minster.york.ac.uk> wgt-a@minster.york.ac.uk writes:
- >>Help! Does anyone know what value variable-resistors
- >>are required for the joysick port on an IBM PC?
- >
- >100K
- >
- >>And, as an aside, can anyone give a good reason why
- >>they used open ended resistors, necessitating (SP?)
- >>particular value resistors, when a potentiometer
- >>setup (as in the good ol' BBC) would have
- >>been MUCH more sensible?
- >
- >Because it's the timing resistor of a circuit whose pulse width can be
- >counted.
- >
- >Here are the details of the joystick connection.
- >
- >You can attach two joysticks to the controller. Each joystick follows
- >this wiring diagram:
- >
- > +------------------ 1,9 +5VDC
- > |
- > +---/\/\/\-- 0-100K
- > | ^
- > | | X-coord
- > | +------------ 3,11 Timer
- > |
- > +---/\/\/\-- 0-100K
- > ^
- > | Y-coord
- > +---------- 6,13 Timer
- >
- > +------------------ 2,10 To 1k Pullups
- > | o #1 Button
- > | o
- > +------------------ 4,12 GND
- >
- > +------------------ 7,14 To 1k Pullups
- > | o #2 Button
- > | o
- > +------------------ 4,12 GND
- >
- >Pins 1-7 Are for Joystick A, pins 9-14 are for joystick B. You can also
- >use paddles, having only one 0-100K pot and one button per controller.
- >The data show up in the same place but are named differently. Here's a
- >chart of the the byte at 201H:
- >
- >Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
- >Joystick|B-#2 |B-#1 |A-#2 |A-#1 | B-Y | B-X | A-Y | A-X |
- >Paddle | D | C | B | A | D | C | B | A |
- >Pin | 14 | 10 | 7 | 2 | 13 | 11 | 6 | 3 |
- >Device |<-------Buttons------->|<------Resistors------>|
- >
-
-
- Well, it confused me--so I got it wrong. The buttons *do not* go to
- one-shots. On the card, each button connects through 1000 Ohms to
- +5VDC, through 51pF to ground, and to one input of the 74LS244 bus driver.
-
- Here's what the tech reference says:
-
- The four digital inputs each have a 1-kilohm pullup resistor to +5 Vdc.
- With no drives on these inputs, a 1 is read. For a 0 reading, the
- inputs must be pulled to ground.
-
- The trigger button inputs are read by an In from address hex 201.
-
- Now as to the real position of the one-shots, they are on the resistor
- inputs to convert resistance to delay time.
-
- My thanks to geir.pedersen@usit.uio.no for questioning the prior post
- and makiing me realize my error. My apologies to the rest of you.
-
- --
- Kirtland H. Olson olson%mydual.uucp@alliant.com
-