Apple Joystick IIe/IIc
| Apple Joystick IIe/IIc | |
|---|---|
 |
|
| Apple Joystick IIe/IIc | |
| Manufacturer | Apple Computer, Inc. |
| Type | Joystick (analogue, self-centring) |
| Price | US$59.95 (Joystick //e, February 1984) |
| Interface | 9-pin D-type game port |
| Compatible | Apple IIe, Apple IIc |
| Model | A2M2002 (Joystick //e) |
| Part number | 661-95133 (service, platinum) |
The Apple Joystick IIe/IIc is Apple's self-centring analogue joystick for the 9-pin game port of the Apple IIe and Apple IIc. Apple's February 1984 dealer price list gives $59.95 for the Joystick //e, A2M2002.[1] It has two buttons and two thumbwheels underneath for centring, and its self-centring can be released axis by axis.[2]
How the Apple II reads it
Each axis is a potentiometer. The IIe connects each hand-control input to one section of a 558 quad timer: a variable resistance of up to 150K ohms between the input and +5 V sets how long one of four 0.022 µF capacitors takes to charge, and software counts that time.[3] Programs read the two axes as PDL(0) and PDL(1), each from 0 to 255.[2] The comp.sys.apple2 FAQ gives 150K ohms as the standard Apple II joystick potentiometer, against 100K for most PC joysticks.[4]
The button nearest the Apple logo is switch 0 and the other is switch 1.[2] The FAQ describes the Apple button circuit: each switch goes to +5 V, its other side goes to ground through a resistor, and the output is taken from the junction. An unpressed button reads near 0 V and a pressed one +5 V, so a continuity test to ground will mislead; measure the output for the swing instead. The FAQ's diagram shows 680 ohms.[4] Apple's service parts list for this joystick includes a "Joystick Resistor, 270 ohm" (101-4271) without saying where it fits, so check the fitted part before replacing it.[5]
Connector
| Signal | 9-pin plug | Older 16-pin IC-style plug |
|---|---|---|
| +5 V | 2 | 1 |
| Button 0 | 7 | 2 |
| X-axis | 5 | 6 |
| Y-axis | 8 | 10 |
| Button 1 | 1 | 3 |
| Ground | 3 | 8 |
Older Apple II joysticks use a 16-pin plug that fits the internal game I/O socket instead of the rear 9-pin port; both carry the same six signals.[4][3] On the IIe the game port is on the left of the back panel, marked with a picture of hand controllers; on the IIc it is the first port from the left, marked with a joystick. Switch off and unplug the computer before connecting the joystick, and tighten the plug's screws.[2]
Adjustment
Apple's instructions give two ways to centre the stick.[2]
For approximate centring, turn the two thumbwheels on the underside until the largest notch on each wheel is in the centre position.
For accurate centring:
- Start the computer from a DOS 3.3 or ProDOS System Master disk, with the stick in its centre position.
- Type and run this Applesoft program:
10 HOME 20 VTAB 6: PRINT "PDL(0) PDL(1)" 30 IF PEEK ( - 16287) > 127 THEN INVERSE 40 VTAB 8: PRINT PDL(0); : NORMAL : PRINT " " 50 IF PEEK ( - 16286) > 127 THEN INVERSE 60 VTAB 8: HTAB 10: PRINT PDL(1); : NORMAL : PRINT " " 70 GOTO 30
- Hold the joystick with the cable end away from you. Moving the stick fully towards the cable end should give PDL(1) = 0, and fully away 255; fully left should give PDL(0) = 0, and fully right 255.
- Return the stick to centre and turn the thumbwheels until both numbers read as close to 128 as possible.
Lines 30 and 50 read the button inputs at $C061 and $C062 (−16287 and −16286) and print the value in inverse while a button is held, so the program also tests the buttons.[2] The comp.sys.apple2 FAQ gives the same test: a stick that reaches 0 and 255 on both axes, centres around 128 and has two working buttons is correctly adjusted.[4]
Releasing the self-centring
The self-centring can be released for each direction separately. Turn the joystick upside down to see the key marks X1, X2, Y1 and Y2. Hold the stick away from the cable end and turn X1 half a turn with a small screwdriver; hold it towards the cable end and turn X2 half a turn; hold it left and turn Y1; hold it right and turn Y2. With all four released, the key marks face each other. To restore self-centring, turn the marks back to their original positions; the stick does not need to be held.[2]
Testing and repair
With the joystick unplugged, measure the resistance between the +5 V pin and each axis pin while moving the stick through its full travel on that axis. The reading should change smoothly, with no jumps or open circuit.[4] If the readings jump, clean the potentiometer tracks with contact cleaner, work the stick through its full range, and let it dry before reassembly. If the track is worn, Apple's service part for the potentiometer mechanism is the gimbal assembly, 699-0097.[5]
For a button that does nothing, measure the button output pin, not the switch. If it stays near 0 V when pressed, the switch or its wiring is open; if it stays at +5 V, the switch is shorted or its resistor is open.[4]
| Part number | Description |
|---|---|
| 661-95133 | Joystick, IIe-IIc, platinum |
| 590-0187 | Joystick cable, IIe-IIc, beige |
| 590-0560 | Joystick cable, IIe-IIc, smoke |
| 101-4271 | Joystick resistor, 270 ohm |
| 699-0097 | Joystick gimbal assembly |
Using a PC joystick instead
According to the comp.sys.apple2 FAQ, a PC game port works with Apple 150K pots but may reach its maximum early in the stick's travel; a 300K resistor across each pot, from the wiper to the end with a wire on it, corrects this. Converting an Apple stick for a PC means opening it and rewiring the buttons, because the two button circuits differ.[4]
Documentation
- Apple Joystick IIe and IIc User's Instructions (030-0971-A)
- Apple hand controller and Joystick IIe-IIc parts lists
- Apple Joystick IIe and IIc User's Instructions
Related pages
References
- ↑ Apple Dealer Price Lists for Apple III, Apple II, Macintosh and Lisa, Apple Computer, Inc., 15 February 1984, hosted as Apple Dealer Price Lists February 1984 (PDF). Apple II accessories: A2M2002 Joystick //e, $59.95.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Apple Joystick IIe and IIc User's Instructions, Apple Computer, Inc., part number 030-0971-A, hosted as File:Apple Joystick IIe and IIc Users Instructions.pdf: installing the joystick; approximately and accurately centring the stick, with the Applesoft test program; releasing the self-centring function; the buttons.
- ↑ 3.0 3.1 Apple IIe Reference Manual (Apple II Reference Manual, For //e Only), Apple Computer, Inc., 1982, hosted as File:Apple IIe Reference Manual 1982.pdf. Chapter 2, "The Hand Control Connector Signals", and Chapter 7, game I/O: the 558 timer inputs, a variable resistance of up to 150K ohms to +5 V, the 0.022 µF timing capacitors, and the 16-pin internal connector.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Csa2 Apple II FAQs: Input Devices, file Csa2KBPADJS.txt, revision 225, December 2016, comp.sys.apple2 Usenet FAQ, gswv.apple2.org.za. Community FAQ, questions 004, 005 and 030: the Apple II and PC joystick pinouts, the 150K ohm Apple pot, the Apple button circuit (diagram with a 680 ohm resistor), the 300K resistor for PC game ports, and the 0-255 adjustment check.
- ↑ 5.0 5.1 5.2 Apple Service Technical Procedures: Apple II/Apple III Archived Products, Volume Two, part number 072-0231, "Miscellaneous Illustrated Parts", hosted as File:Apple II Hand Controller and Joystick IIe-IIc Parts Lists.pdf. Figure 2, Joystick Assembly, p. 1.4 (rev. Sep 85), and parts list p. 1.5 (rev. Apr 87).