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Created page with "<pre> ;simple keyboard module ;no extra functions , just scan and locate a key ;no char buffer , no antibounce, ect... ;SJASM syntax MODULE key ;do a complete key scan and..."
<pre>
;simple keyboard module
;no extra functions , just scan and locate a key
;no char buffer , no antibounce, ect...
;SJASM syntax
MODULE key
;do a complete key scan and store it at (HL)
;altered : AF - BC - DE
Scan
push HL
ld BC,#F782
out (C),C
ld BC,#F40e
ld E,B
out (C),C
ld BC,#F6c0
ld D,B
out (C),C
ld C,0
out (C),C
ld BC,#F792
out (C),C
ld A,#40
ld C,#4A
.loop
ld B,D
out (C),A
ld B,E
ini
inc A
cp C
jr c,.loop
ld BC,#F782
out (C),C
pop HL
ret
;check if there is a key is down at (HL);only the first key found is returned
;return carry is a key is down
;return key code in A : key code = (line*8)+bit
;returned code is the same than system
;altered : AF - BC
GetPressed
push HL
ld C,10.loop_col
ld B,8
ld A,(HL++).loop_bit
rla jr nc,.pressed
djnz .loop_bit
dec C
jr nz,.loop_col
or A ;no key found !
pop HL
ret
.pressed
dec C
ld A,9
sub C
add A ;*2
add A ;*4
add A ;*8
dec B
or B ;add bit
scf ;key found !
pop HL
ret
;check if a key is pressed
;A = key code
;HL = 10 byte array scanned with Scan function
;return key state in carry
;altered AF - DE - B
IsPressed
push HL
push AF ; keep bit
and %01111000
rrca
rrca
rrca
ld E,A ld D,0
add HL,DE
;so we get the address
pop AF
;now get the
and 7
inc A
ld B,A
ld A,(HL)
;get line
.loop
rra ;get bit in carry
djnz .loop
ccf ;reverse bit
pop HL
ret
;compute offset and mask for a key
;A = key code
;return offset in C and mask in B
;altered AF - BC
GetMask
ld B,A
;get offset
and %01111000
rrca
rrca
rrca
ld C,A
;get mask
ld A,B
and %00000111
ld B,A
ld A,1
jr z,.done
.loop
add A
djnz .loop
.done
ld B,A
ret
;erase SHIFT and CONTROL status
;used when that can be a problem , like with IsPressed
;HL = 10 byte array scanned with Scan function
;altered : AF
IgnoreSHITFCTRL
push HL
inc HL
inc HL
ld A,(HL)
or %10100000
ld (HL),A
pop HL
ret
ENDMODULE</pre>
;simple keyboard module
;no extra functions , just scan and locate a key
;no char buffer , no antibounce, ect...
;SJASM syntax
MODULE key
;do a complete key scan and store it at (HL)
;altered : AF - BC - DE
Scan
push HL
ld BC,#F782
out (C),C
ld BC,#F40e
ld E,B
out (C),C
ld BC,#F6c0
ld D,B
out (C),C
ld C,0
out (C),C
ld BC,#F792
out (C),C
ld A,#40
ld C,#4A
.loop
ld B,D
out (C),A
ld B,E
ini
inc A
cp C
jr c,.loop
ld BC,#F782
out (C),C
pop HL
ret
;check if there is a key is down at (HL);only the first key found is returned
;return carry is a key is down
;return key code in A : key code = (line*8)+bit
;returned code is the same than system
;altered : AF - BC
GetPressed
push HL
ld C,10.loop_col
ld B,8
ld A,(HL++).loop_bit
rla jr nc,.pressed
djnz .loop_bit
dec C
jr nz,.loop_col
or A ;no key found !
pop HL
ret
.pressed
dec C
ld A,9
sub C
add A ;*2
add A ;*4
add A ;*8
dec B
or B ;add bit
scf ;key found !
pop HL
ret
;check if a key is pressed
;A = key code
;HL = 10 byte array scanned with Scan function
;return key state in carry
;altered AF - DE - B
IsPressed
push HL
push AF ; keep bit
and %01111000
rrca
rrca
rrca
ld E,A ld D,0
add HL,DE
;so we get the address
pop AF
;now get the
and 7
inc A
ld B,A
ld A,(HL)
;get line
.loop
rra ;get bit in carry
djnz .loop
ccf ;reverse bit
pop HL
ret
;compute offset and mask for a key
;A = key code
;return offset in C and mask in B
;altered AF - BC
GetMask
ld B,A
;get offset
and %01111000
rrca
rrca
rrca
ld C,A
;get mask
ld A,B
and %00000111
ld B,A
ld A,1
jr z,.done
.loop
add A
djnz .loop
.done
ld B,A
ret
;erase SHIFT and CONTROL status
;used when that can be a problem , like with IsPressed
;HL = 10 byte array scanned with Scan function
;altered : AF
IgnoreSHITFCTRL
push HL
inc HL
inc HL
ld A,(HL)
or %10100000
ld (HL),A
pop HL
ret
ENDMODULE</pre>
