Kempston Joystick 2, Joystick I/O: Difference between revisions
m Ped7g moved page Kempston Joystick 2 to Kempston Joystick 2, Joystick I/O: core3.1.4 adds I/O mode on joystick ports |
core 3.1.4 changes/refresh |
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{{Port | {{Port | ||
|Number=$xx37 | |Number=$xx37 | ||
|ShortDesc= | |ShortDesc=Kempston interface second joystick variant and controls joystick I/O. | ||
|Readable=Yes | |Readable=Yes | ||
|Writable= | |Writable=Yes | ||
|Subsystem=Input | |Subsystem=Input | ||
}} | }} | ||
For READ functionality the details are identical with {{PortNo|$xx1F}} | |||
Since core3.1.4 (but needs fixing, so 3.1.5 probably) there is option to do I/O operations through joystick ports. | |||
The I/O mode should be set by writing this port first followed by enabling I/O mode on the joysticks with a write to {{NextRegNo|$05}}. | |||
The WRITE functionality: | |||
{| class="wikitable" | |||
! Bit !! Function | |||
|- | |||
| 7-6 || select I/O mode: %00 = bit bang, %01 = clock, %10 = uart | |||
|- | |||
| 5-1 || Reserved must be 0 | |||
|- | |||
| 0 || parameter bit controls state of pin 7 on both joystick connectors: | |||
bit bang: bit 0 is copied to pin 7<br> | |||
clock: 0 = place slow clock on pin 7 (Fsys/2048 = 13.672kHz), 1 = place fast clock on pin 7 (Fsys/8 = 3.5MHz) †<br> | |||
uart: 0 = redirect esp uart to joystick connector, 1 = redirect pi uart to joystick connector (Tx appears on pin 7, Rx taken from pin 9) | |||
|} | |||
† A runt clock pulse may appear in the first cycle, minimum pulse width is 1/Fsys = 35.7ns | |||
Revision as of 10:19, 15 April 2020
| Number | PortNumber::$xx37 |
|---|---|
| Decimal | NumberDec:: |
| Short desc. | ShortDesc::Kempston interface second joystick variant and controls joystick I/O. |
| Bit Mask | PortMask:: |
| Readable | Readable::Yes |
| Writable | Writable::Yes |
| Subsystem | Subsystem::Input |
For READ functionality the details are identical with {{#ask: PortNumber::$xx1F }} ($xx1F{{#ask: PortNumber::$xx1F |mainlabel=- |headers=hide |intro= / |?NumberDec#- }})
Since core3.1.4 (but needs fixing, so 3.1.5 probably) there is option to do I/O operations through joystick ports.
The I/O mode should be set by writing this port first followed by enabling I/O mode on the joysticks with a write to {{#ask: TBRegisterNumber::$05 }} ($05).
The WRITE functionality:
| Bit | Function |
|---|---|
| 7-6 | select I/O mode: %00 = bit bang, %01 = clock, %10 = uart |
| 5-1 | Reserved must be 0 |
| 0 | parameter bit controls state of pin 7 on both joystick connectors:
bit bang: bit 0 is copied to pin 7 |
† A runt clock pulse may appear in the first cycle, minimum pulse width is 1/Fsys = 35.7ns