2019-07-15 12:21:50 +00:00
|
|
|
|
[< back to index](../doc_index.md)
|
2018-07-12 16:30:35 +00:00
|
|
|
|
|
2019-06-26 13:51:09 +00:00
|
|
|
|
## keyboard
|
|
|
|
|
|
|
|
|
|
|
|
The `keyboard` module provides support for reading keypresses from the keyboard.
|
|
|
|
|
|
Not supported on all targets.
|
|
|
|
|
|
|
|
|
|
|
|
#### `byte readkey()`
|
|
|
|
|
|
|
|
|
|
|
|
Waits for and reads a single keypress.
|
|
|
|
|
|
|
|
|
|
|
|
The returning values may vary between platforms:
|
|
|
|
|
|
|
|
|
|
|
|
* letters may be uppercase or lowercase
|
|
|
|
|
|
|
|
|
|
|
|
* modifier keys may be applied or ignored
|
|
|
|
|
|
|
|
|
|
|
|
Available for:
|
|
|
|
|
|
Commodore 64 (requires KERNAL),
|
|
|
|
|
|
Commodore 16 or Plus/4 (requires KERNAL),
|
|
|
|
|
|
Commodore 128 (requires KERNAL),
|
|
|
|
|
|
VIC 20 (requires KERNAL),
|
|
|
|
|
|
Atari,
|
|
|
|
|
|
Amstrad CPC,
|
|
|
|
|
|
ZX Spectrum,
|
|
|
|
|
|
NEC PC-88.
|
|
|
|
|
|
|
|
|
|
|
|
#### `const byte KEY_ENTER`
|
|
|
|
|
|
|
|
|
|
|
|
Key code for the Enter/Return key. Usually 13, but not always.
|
|
|
|
|
|
|
2018-12-19 18:01:53 +00:00
|
|
|
|
## err
|
2018-07-12 16:30:35 +00:00
|
|
|
|
|
2018-12-19 18:01:53 +00:00
|
|
|
|
#### `enum error_number`
|
|
|
|
|
|
|
|
|
|
|
|
Standard error codes. All codes other than `err_ok` suggest that the last operation failed.
|
|
|
|
|
|
|
|
|
|
|
|
#### `error_number errno`
|
|
|
|
|
|
|
|
|
|
|
|
The result of the last operation.
|
2018-12-30 17:59:32 +00:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
## random
|
|
|
|
|
|
|
|
|
|
|
|
A simple and reasonably fast random number generator. Not suitable for cryptographic or simulation uses.
|
|
|
|
|
|
|
|
|
|
|
|
#### `word rand_seed`
|
|
|
|
|
|
|
|
|
|
|
|
Random number generator state.
|
|
|
|
|
|
|
|
|
|
|
|
#### `byte rand()`
|
|
|
|
|
|
|
|
|
|
|
|
Get a random byte (0–255) and update the state of the generator.
|
|
|
|
|
|
|
|
|
|
|
|
#### `void init_rand_seed()`
|
|
|
|
|
|
|
|
|
|
|
|
Initializes the random number generator state.
|
|
|
|
|
|
This may take a long time, even several frames, depending on the target.
|
|
|
|
|
|
|
|
|
|
|
|
Current implementation:
|
|
|
|
|
|
|
|
|
|
|
|
* On C64, spends two frames reading noise data from the SID chip.
|
|
|
|
|
|
|
|
|
|
|
|
* On Z80, reads the refresh register.
|
|
|
|
|
|
|
|
|
|
|
|
* On all other targets, sets the seed to 1.
|
