Difference between revisions of "MultiPlay"
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&F996 and &F997 ports are unused. | &F996 and &F997 ports are unused. | ||
| − | Mouse register X/Y return the offset since the last read. These are 4 bit value with sign extension. The 4 values are sign extended to 8 bit, so negative value will have bit7-4 at one. In fact bit 7-4 = bit 3 | + | Mouse register X/Y return the offset since the last read. These are 4 bit value with sign extension. The 4 values are sign extended to 8 bit, so negative value will have bit7-4 at one. In fact bit 7-4 = bit 3. |
Note also that the X/Y value will saturate if not read for a long time (or if the movement is fast). It will never overflow or wrap. | Note also that the X/Y value will saturate if not read for a long time (or if the movement is fast). It will never overflow or wrap. | ||
Revision as of 15:23, 31 May 2024
The MultiPlay allows to add two controllers on the expansion port. It is easy to use them from BASIC, with the INP() command.
Each controller port can be set with two inputs modes:
Each mouse sensitivity is 200dpi / 4bit acceleration. (DK'Tronics mouse is 50dpi / 1bit) Last but not least: Left, Middle and Right buttons are supported.
50Hz games support w/o conflict. It is handled like arcade machines!
Technical
200 DPI (1 inch = 200 pixel movement) ________ ________ A _____| |________| |________ ________ ________ B _________| |________| |________ 200 DPI |1 |2 |3 |4 |5 |6 |7 |8 50 DPI |1 |2
About usages:
- Reading from BASIC with 50Hz interrupt is fine to handle a fast char pointer with acceleration.
- Reading from ASM with 300Hz interrupt is fine to handle a fast pixel pointer with acceleration.
I/O ports
Port &F990 : 0321RLDU : Input A, joystick and buttons
Port &F991 : 0321RLDU : Input B, joystick and buttons
Port &F992 : 0000XXXX : Input A, mouse X
Port &F993 : 0000YYYY : Input A, mouse Y
Port &F994 : 0000XXXX : Input B, mouse X
Port &F995 : 0000YYYY : Input B, mouse Y
Buttons 1, 2, 3 are the same for joystick and mouse input A/B.
&F996 and &F997 ports are unused.
Mouse register X/Y return the offset since the last read. These are 4 bit value with sign extension. The 4 values are sign extended to 8 bit, so negative value will have bit7-4 at one. In fact bit 7-4 = bit 3.
Note also that the X/Y value will saturate if not read for a long time (or if the movement is fast). It will never overflow or wrap.
From a software point of view, just read the port and add its value to your position variable.
Downloads
- Any MultiPlay example or driver software exists?
