ti/kbd: implement A-Lock

ref #41
This commit is contained in:
Virgil Dupras 2019-11-08 20:27:43 -05:00
parent 8d5c26f299
commit c896b77143
2 changed files with 63 additions and 22 deletions

View File

@ -5,8 +5,24 @@
; *** Constants ***
.equ KBD_PORT 0x01
; Keys that have a special meaning in GetC. All >= 0x80. They are interpreted
; by GetC directly and are never returned as-is.
.equ KBD_KEY_ALPHA 0x80
.equ KBD_KEY_2ND 0x81
; *** Variables ***
; active long-term modifiers, such as a-lock
; bit 0: A-Lock
.equ KBD_MODS KBD_RAMSTART
.equ KBD_RAMEND @+1
; *** Code ***
kbdInit:
xor a
ld (KBD_MODS), a
ret
; Wait for a digit to be pressed and sets the A register ASCII value
; corresponding to that key press.
;
@ -24,8 +40,14 @@ kbdGetC:
push bc
push hl
; During this GetC loop, register C holds the modificators (Alpha, 2nd)
ld c, 0
; During this GetC loop, register C holds the modificators
; bit 0: Alpha
; bit 1: 2nd
; Initial value should be zero, but if A-Lock is on, it's 1
ld a, (KBD_MODS)
and 1
ld c, a
; loop until a digit is pressed
.loop:
ld hl, .dtbl
@ -60,22 +82,29 @@ kbdGetC:
ld a, (hl)
or a ; is char 0?
jr z, .loop ; yes? unsupported. loop.
cp 0x80 ; is it alpha?
jr nz, .notalpha
call .debounce
cp KBD_KEY_ALPHA
jr c, .end ; A < 0x80? valid char, return it.
jr z, .handleAlpha
cp KBD_KEY_2ND
jr z, .handle2nd
jp .loop
.handleAlpha:
set 0, c
jr .loop
.notalpha:
; wait until all keys are de-pressed
push af ; --> lvl 1
.wait:
xor a
call .get
inc a ; if a was 0xff, will become 0 (nz test)
jr nz, .wait ; non-zero? something is pressed
pop af ; <-- lvl 1
bit 1, c ; 2nd set?
jp z, .loop ; unset? loop
; we've just hit Alpha with 2nd set. Toggle A-Lock and set Alpha to
; the value A-Lock has.
ld a, (KBD_MODS)
xor 1
ld (KBD_MODS), a
ld c, a
jp .loop
.handle2nd:
set 1, c
jp .loop
.end:
pop hl
pop bc
ret
@ -89,18 +118,28 @@ kbdGetC:
in a, (KBD_PORT)
ei
ret
.debounce:
; wait until all keys are de-pressed
push af ; --> lvl 1
.wait:
xor a
call .get
inc a ; if a was 0xff, will become 0 (nz test)
jr nz, .wait ; non-zero? something is pressed
pop af ; <-- lvl 1
ret
; digits table. each row represents a group. first item is group mask.
; 0 means unsupported. no group 7 because it has no keys.
; 0x80 is a special value for ALPHA key which is never returned directly.
.dtbl:
.db 0xfe, 0, 0, 0, 0, 0, 0, 0, 0
.db 0xfd, 0x0d, '+' ,'-' ,'*', '/', '^', 0, 0
.db 0xfb, 0, '3', '6', '9', ')', 0, 0, 0
.db 0xf7, '.', '2', '5', '8', '(', 0, 0, 0
.db 0xef, '0', '1', '4', '7', ',', 0, 0, 0
.db 0xdf, 0, 0, 0, 0, 0, 0, 0, 0x80
.db 0xbf, 0, 0, 0, 0, 0, 0, 0, 0x7f
.db 0xdf, 0, 0, 0, 0, 0, 0, 0, KBD_KEY_ALPHA
.db 0xbf, 0, 0, 0, 0, 0, KBD_KEY_2ND, 0, 0x7f
; alpha table. same as .dtbl, for when we're in alpha mode.
.atbl:
@ -109,5 +148,5 @@ kbdGetC:
.db 0xfb, '?', 0, 'V', 'Q', 'L', 'G', 0, 0
.db 0xf7, ':', 'Z', 'U', 'P', 'K', 'F', 'C', 0
.db 0xef, '_', 'Y', 'T', 'O', 'J', 'E', 'B', 0
.db 0xdf, 0, 'X', 'S', 'N', 'I', 'D', 'A', 0x80
.db 0xbf, 0, 0, 0, 0, 0, 0, 0, 0x7f
.db 0xdf, 0, 'X', 'S', 'N', 'I', 'D', 'A', KBD_KEY_ALPHA
.db 0xbf, 0, 0, 0, 0, 0, KBD_KEY_2ND, 0, 0x7f

View File

@ -28,8 +28,9 @@
.inc "fnt/mgm.asm"
.equ LCD_RAMSTART RAMSTART
.inc "ti/lcd.asm"
.equ KBD_RAMSTART LCD_RAMEND
.inc "ti/kbd.asm"
.equ STDIO_RAMSTART LCD_RAMEND
.equ STDIO_RAMSTART KBD_RAMEND
.equ STDIO_GETC kbdGetC
.equ STDIO_PUTC lcdPutC
.inc "stdio.asm"
@ -60,6 +61,7 @@ boot:
halt
main:
call kbdInit
call lcdInit
xor a
call lcdSetCol