msbasic/var.s
2008-10-13 02:14:07 +00:00

243 lines
5.3 KiB
ArmAsm

.segment "CODE"
; ----------------------------------------------------------------------------
; "DIM" STATEMENT
; ----------------------------------------------------------------------------
NXDIM:
jsr CHKCOM
DIM:
tax
jsr PTRGET2
jsr CHRGOT
bne NXDIM
rts
; ----------------------------------------------------------------------------
; PTRGET -- GENERAL VARIABLE SCAN
;
; SCANS VARIABLE NAME AT TXTPTR, AND SEARCHES THE
; VARTAB AND ARYTAB FOR THE NAME.
; IF NOT FOUND, CREATE VARIABLE OF APPROPRIATE TYPE.
; RETURN WITH ADDRESS IN VARPNT AND Y,A
;
; ACTUAL ACTIVITY CONTROLLED SOMEWHAT BY TWO FLAGS:
; DIMFLG -- NONZERO IF CALLED FROM "DIM"
; ELSE = 0
;
; SUBFLG -- = $00
; = $40 IF CALLED FROM "GETARYPT"
; ----------------------------------------------------------------------------
PTRGET:
ldx #$00
jsr CHRGOT
PTRGET2:
stx DIMFLG
PTRGET3:
sta VARNAM
jsr CHRGOT
jsr ISLETC
bcs NAMOK
SYNERR3:
jmp SYNERR
NAMOK:
ldx #$00
stx VALTYP
.ifndef CONFIG_SMALL
stx VALTYP+1
.endif
jsr CHRGET
bcc L2ECD
jsr ISLETC
bcc L2ED8
L2ECD:
tax
L2ECE:
jsr CHRGET
bcc L2ECE
jsr ISLETC
bcs L2ECE
L2ED8:
cmp #$24
.ifdef CONFIG_SMALL
bne L2EF9
.else
bne L2EE2
.endif
lda #$FF
sta VALTYP
.ifndef CONFIG_SMALL
bne L2EF2
L2EE2:
cmp #$25
bne L2EF9
lda SUBFLG
bne SYNERR3
lda #$80
sta VALTYP+1
ora VARNAM
sta VARNAM
L2EF2:
.endif
txa
ora #$80
tax
jsr CHRGET
L2EF9:
stx VARNAM+1
sec
ora SUBFLG
sbc #$28
bne L2F05
jmp ARRAY
L2F05:
lda #$00
sta SUBFLG
lda VARTAB
ldx VARTAB+1
ldy #$00
L2F0F:
stx LOWTR+1
L2F11:
sta LOWTR
cpx ARYTAB+1
bne L2F1B
cmp ARYTAB
beq NAMENOTFOUND
L2F1B:
lda VARNAM
cmp (LOWTR),y
bne L2F29
lda VARNAM+1
iny
cmp (LOWTR),y
beq SET_VARPNT_AND_YA
dey
L2F29:
clc
lda LOWTR
adc #BYTES_PER_VARIABLE
bcc L2F11
inx
bne L2F0F
; ----------------------------------------------------------------------------
; CHECK IF (A) IS ASCII LETTER A-Z
;
; RETURN CARRY = 1 IF A-Z
; = 0 IF NOT
; ----------------------------------------------------------------------------
ISLETC:
cmp #$41
bcc L2F3C
sbc #$5B
sec
sbc #$A5
L2F3C:
rts
; ----------------------------------------------------------------------------
; VARIABLE NOT FOUND, SO MAKE ONE
; ----------------------------------------------------------------------------
NAMENOTFOUND:
pla
pha
cmp #<FRM_VARIABLE_CALL
bne MAKENEWVARIABLE
.ifdef CONFIG_SAFE_NAMENOTFOUND
tsx
lda STACK+2,x
cmp #>FRM_VARIABLE_CALL
bne MAKENEWVARIABLE
.endif
LD015:
lda #<C_ZERO
ldy #>C_ZERO
rts
; ----------------------------------------------------------------------------
.ifndef CBM2_KBD
C_ZERO:
.byte $00,$00
.endif
; ----------------------------------------------------------------------------
; MAKE A NEW SIMPLE VARIABLE
;
; MOVE ARRAYS UP 7 BYTES TO MAKE ROOM FOR NEW VARIABLE
; ENTER 7-BYTE VARIABLE DATA IN THE HOLE
; ----------------------------------------------------------------------------
MAKENEWVARIABLE:
.ifdef CONFIG_CBM_ALL
lda VARNAM
ldy VARNAM+1
cmp #$54
bne LD02F
cpy #$C9
beq LD015
cpy #$49
bne LD02F
LD02C:
jmp SYNERR
LD02F:
cmp #$53
bne LD037
cpy #$54
beq LD02C
LD037:
.endif
lda ARYTAB
ldy ARYTAB+1
sta LOWTR
sty LOWTR+1
lda STREND
ldy STREND+1
sta HIGHTR
sty HIGHTR+1
clc
adc #BYTES_PER_VARIABLE
bcc L2F68
iny
L2F68:
sta HIGHDS
sty HIGHDS+1
jsr BLTU
lda HIGHDS
ldy HIGHDS+1
iny
sta ARYTAB
sty ARYTAB+1
ldy #$00
lda VARNAM
sta (LOWTR),y
iny
lda VARNAM+1
sta (LOWTR),y
lda #$00
iny
sta (LOWTR),y
iny
sta (LOWTR),y
iny
sta (LOWTR),y
iny
sta (LOWTR),y
.ifndef CONFIG_SMALL
iny
sta (LOWTR),y
.endif
; ----------------------------------------------------------------------------
; PUT ADDRESS OF VALUE OF VARIABLE IN VARPNT AND Y,A
; ----------------------------------------------------------------------------
SET_VARPNT_AND_YA:
lda LOWTR
clc
adc #$02
ldy LOWTR+1
bcc L2F9E
iny
L2F9E:
sta VARPNT
sty VARPNT+1
rts