Difference between revisions of "Programming:Keyboard scanning"
From CPCWiki - THE Amstrad CPC encyclopedia!
(Initial page) |
(added routine for complete keyboard scanning) |
||
| Line 1: | Line 1: | ||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
== Hardware scancode table == | == Hardware scancode table == | ||
{|{{Prettytable|width: 700px; font-size: 2em;}} | {|{{Prettytable|width: 700px; font-size: 2em;}} | ||
| Line 33: | Line 24: | ||
|} | |} | ||
| − | == | + | == 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 = ''layer (&40 - &49) | ||
| + | |||
| + | '''Output:''' A = ''hardware keyboard value'' | ||
| + | |||
| + | '''Destroyed:''' BC | ||
| + | |||
<pre> | <pre> | ||
ld a, layer ;use the value from the table above | ld a, layer ;use the value from the table above | ||
| Line 50: | Line 50: | ||
ld bc, &F600 | ld bc, &F600 | ||
out (c), c | out (c), c | ||
| + | </pre> | ||
| + | |||
| + | Now check for the value from the table | ||
| + | e.g. with''' 'cp <value>' ''' | ||
| + | and a condition | ||
| + | e.g.''' 'jp <condition>, xxxx' '''or''' 'call <condition>, 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. | ||
| + | |||
| + | <pre> | ||
| + | keymap ds 10 ;map with 10*8 = 80 key status bits (bit=0 key is pressed) | ||
| − | ; | + | keyscan di ;1 ##%%## C P C VERSION ##%%## |
| − | ;e | + | ld hl,keymap ;3 |
| − | ; | + | ld bc,#f782 ;3 |
| − | ;e | + | 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 | ||
</pre> | </pre> | ||
Revision as of 07:57, 27 August 2006
Hardware scancode table
| Value: Layer |
&7F | &BF | &DF | &EF | &F7 | &FB | &FD | &FE |
| &40 | (ZB) | 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 = layer (&40 - &49)
Output: A = hardware keyboard value
Destroyed: BC
ld a, layer ;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 'cp <value>' and a condition e.g. 'jp <condition>, xxxx' or 'call <condition>, 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
