Difference between revisions of "83Plus:BCALLs:4015"
From WikiTI
(Describe key repeat handling.) |
|||
| (6 intermediate revisions by 4 users not shown) | |||
| Line 1: | Line 1: | ||
| − | [[Category:83Plus:BCALLs:By Name: | + | [[Category:83Plus:BCALLs:By Name:Input|KbdScan]] [[Category:83Plus:BCALLs:By Name|KbdScan]] [[Category:83Plus:BCALLs:By Address|4015 - KbdScan]] |
| + | |||
== Synopsis == | == Synopsis == | ||
'''Official Name:''' KbdScan | '''Official Name:''' KbdScan | ||
| Line 5: | Line 6: | ||
'''BCALL Address:''' 4015 | '''BCALL Address:''' 4015 | ||
| − | This routine scans the keyboard for any key presses and updates the memory location | + | This routine scans the keyboard for any key presses and updates the memory location [[83Plus:RAM:843F|kbdScanCode]]. |
=== Inputs === | === Inputs === | ||
| Line 11: | Line 12: | ||
=== Outputs === | === Outputs === | ||
| − | * ( | + | * ([[83Plus:RAM:843F|kbdScanCode]])=scan code of key press |
=== Registers Destroyed === | === Registers Destroyed === | ||
| − | * | + | * All |
== Comments == | == Comments == | ||
| − | Normally this | + | Normally this routine is called by the interrupt routine. If interrupts are not enabled, this can be called prior to [[83Plus:BCALLs:4018|GetCSC]] to achieve the same results. |
| + | |||
| + | Key repeat is handled here, when scanning the keyboard. If any of the arrow keys or DEL is held, they will first be repeated after about 48 calls and every 10 after the first. Holding other keys will not update [[83Plus:RAM:843F|kbdScanCode]] until the key is released. | ||
Latest revision as of 18:37, 17 June 2020
Synopsis
Official Name: KbdScan
BCALL Address: 4015
This routine scans the keyboard for any key presses and updates the memory location kbdScanCode.
Inputs
- none
Outputs
- (kbdScanCode)=scan code of key press
Registers Destroyed
- All
Comments
Normally this routine is called by the interrupt routine. If interrupts are not enabled, this can be called prior to GetCSC to achieve the same results.
Key repeat is handled here, when scanning the keyboard. If any of the arrow keys or DEL is held, they will first be repeated after about 48 calls and every 10 after the first. Holding other keys will not update kbdScanCode until the key is released.
