Atari 1040STE, Field Service Manual

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down, left, right, right button, left button. The right button equals the joystick trigger,
the left button is wired to the second joystick port trigger. The joystick has four
directions (up, down, etc.) and one trigger.
Note.
The Atari CX24 joystick cannot be installed during initialization.
Mouse/Joystick
1 – Up/XB
2 – Down/XA
3 – Left/YA
4 – Right/YB
5 – Not Connected
6 – Fire/Left Button
7 – +5VDC
8 – Ground
9 – Joy1 Fire/Right Button
Joystick
1 – Up
2 – Down
3 – Left
4 – Right
5 – Reserved
6 – Fire Button
7 – +5 VDC
8 – Ground
9 – Not Connected
Figure 2–3: Mouse/Joystick Ports
2.12.4 Parallel lnterface
The parallel port is primarily intended as a Centronics type printer interface, but can
also be used as a general purpose I/O port. Centronics STROBE and BUSY are
supported. BUSY is read by the MFP chip. Data and strobe signals are output by the
YM2149 PSG chip. Not all Centronics printers are compatible with this port. The
current loading on the data lines should not exceed 2.3 mA. (This corresponds to a
2.2k ohm resistor pull–up on the printer side).
The port can be programmed to be input or output. The PSG chip is read directly by
the CPU, with GSTMCU doing address decode to provide chip select.