Difference between revisions of "Programming:Keyboard scanning"
From CPCWiki - THE Amstrad CPC encyclopedia!
(added category) |
|||
| Line 3: | Line 3: | ||
|'''Bit:<br>Line''' || '''7''' || '''6''' || '''5''' || '''4''' || '''3''' || '''2''' || '''1''' || '''0''' | |'''Bit:<br>Line''' || '''7''' || '''6''' || '''5''' || '''4''' || '''3''' || '''2''' || '''1''' || '''0''' | ||
|- | |- | ||
| − | |'''&40''' || | + | |'''&40''' || F Dot || ENTER || F3 || F6 || F9 || CURDOWN || CURRIGHT || CURUP |
|- | |- | ||
|'''&41''' || F0 || F2 || F1 || F5 || F8 || F7 || COPY || CURLEFT | |'''&41''' || F0 || F2 || F1 || F5 || F8 || F7 || COPY || CURLEFT | ||
Revision as of 10:03, 1 September 2006
Hardware scancode table
| Bit: Line |
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| &40 | F Dot | ENTER | F3 | F6 | F9 | CURDOWN | CURRIGHT | CURUP |
| &41 | F0 | F2 | F1 | F5 | F8 | F7 | COPY | CURLEFT |
| &42 | CONTROL | \ | SHIFT | F4 | ] | RETURN | [ | CLR |
| &43 | . | / | : | ; | P | @ | - | ^ |
| &44 | , | M | K | L | I | O | 9 | 0 |
| &45 | SPACE | N | J | H | Y | U | 7 | 8 |
| &46 | V | B | F | G | T | R | 5 | 6 |
| &47 | X | C | D | S | W | E | 3 | 4 |
| &48 | Z | CAPSLOCK | A | TAB | Q | ESC | 2 | 1 |
| &49 | DEL | - | - | - | - | - | - | - |
One line scanning routine
This is a routine which scans one line of the keyboard directly. It is approximately 8% faster then the firmware routine and doesn't enable interrupts.
Input: A = line (&40 - &49)
Output: A = hardware keyboard value
Destroyed: BC
ld a, line ;use the value from the table above ld bc, &F6C0 out (c), c ld bc, &F40E out (c), c ld bc, &F792 out (c), c ld b, &F6 out (c), c ld b, &F4 in a, (c) ld bc, &F782 out (c), c ld bc, &F600 out (c), c
Now check for the value from the table e.g. with 'bit x,A' and a condition e.g. 'jp z,xxxx' or 'call z,xxxx'
Please note:
- Bit = 0: Key is pressed
- Bit = 1: Key is not pressed
Complete keyboard scanning routine
This routine scans the complete keyboard and writes all key status bits in a map.
keymap ds 10 ;map with 10*8 = 80 key status bits (bit=0 key is pressed)
keyscan di ;1 ##%%## C P C VERSION ##%%##
ld hl,keymap ;3
ld bc,#f782 ;3
out (c),c ;4
ld bc,#f40e ;3
ld e,b ;1
out (c),c ;4
ld bc,#f6c0 ;3
ld d,b ;1
out (c),c ;4
ld c,0 ;2
out (c),c ;4
ld bc,#f792 ;3
out (c),c ;4
ld a,#40 ;2
ld c,#4a ;2 44
loop ld b,d ;1
out (c),a ;4 select line
ld b,e ;1
ini ;5 read bits and write into KEYMAP
inc a ;1
cp c ;1
jr c,loop ;2/3 9*16+1*15=159
ld bc,#f782 ;3
out (c),c ;4
ei ;1 8 =211 microseconds
ret
