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C02/include/old/ctype.asm
2018-01-28 13:30:49 -05:00

115 lines
3.9 KiB
NASM

;ctype.h02 assembly language subroutines
;
;C02 Functions modify Accumulator and Flags
; isxxxx will load $FF into Accumulator to and Set Carry if True
; and load $00 into Accumulator to and clear Carry if False
; toxxxx set Carry if character is converted, otherwise clear Carry
;Machine Language Subroutines modify Flags but not Accumulator
; Carry will be Set if True and Cleared if False
;Index Registers are not modified by any routines
;Character Test Functions - Set Accumulator
isalnm: JSR isaln ;Is Alphanumeric Character
BVC isbtf
isalph: JSR isalp; ;Is Alphabetic Character
BVC isbtf
isctrl: JSR isctl ;Is Control Character
BVC isbtf
isdigt: JSR isdgt ;Is Digit
BVC isbtf
isgrph: JSR isgrp ;Is Graphical Character
BVC isbtf
ishdgt: JSR ishex ;Is Hex Digit
BVC isbtf
islowr: JSR islwr ;Is Lowercase Character
BVC isbtf
ispnct: JSR ispnc ;Is Punctuation Character
BVC isbtf
isprnt: JSR isprt ;Is Printable Character
BVC isbtf
isspce: JSR isspc ;Is White Space Character
BVC isbtf
isuppr: JSR isupr ;Is Uppercase Character
BVC isbtf
;Internal Routines - Set Accumulator based on Carry Flag
isbtf: BCC isfls ;If Carry Set
istru: LDA #$FF ; Return TRUE
RTS ;Else
isfls: LDA #$00 ; Return FALSE
RTS
;C02/ML Character Conversion Routines
tolowr: JSR isupr ;If Char is Not Upper Case
BCC isrts ; Return
ORA #$20 ;Else Set Bit 5
RTS ; and Return
touppr: JSR islwr ;If Char is Not Lower Case
BCC isrts ; Return
AND #$DF ;Else Clear Bit 5
RTS ; and Return
;Machine Language Subroutines - Set/Clear Carry, Preserve Accumulator
isaln: JSR isdgt ;If Char is Digit
BCS isrts ; Return Carry Set
;Else
isalp: JSR isupr ;If Char is Upper Case
BCS isrts ; Return Carry Set
;Else
islwr: CMP #$61 ;If Char < 'a'
BCC isrts ; Return with Carry Clear
CMP #$7B ;Else If Char >= '{'
JMP isbcs ; Return with Carry Clear Else Return with Carry Set
isupr: CMP #$41 ;If Char < 'A'
BCC isrts ; Return with Carry Clear
CMP #$5B ;Else If Char >= '['
isbcs: BCS isclc ; Return with Carry Clear
BCC issec ;Else Return with Carry Set
issec: SEC ;Set Carry
BCS isrts ; and Return
isclc: CLC ;Clear Carry
isrts: CLV ;Clear Overflow - for C02 calls
RTS ;Return from Subroutine
isctl: CMP #$7F ;If Char = DEL
BEQ issec ; Return Carry Set
CMP #$20 ;Else If Char < ' '
JMP isbcs ; Return Carry Set Else Return Carry Clear
isdgt: CMP #$30 ;If Char < '0'
BCC isrts ; Return Carry Clear
CMP #$3A ;Else If Char >= ':'
JMP isbcs ; Return FALSE Else Return TRUE
ispnc: JSR isaln ;If Char is Alphanumeric
BCS isclc ; Return Carry Clear
;Else
isgrp: CMP #$20 ;If Char is Space
BEQ isclc ; Return Carry Clear
;Else
isprt: CMP #$80 ;If Char is High ASCII
BCS isclc ; Return Carry Clear
JSR isctl ;If Char is Not Control
JMP isbcs ; Return Carry Clear Else Return Carry Set
isspc: CMP #$20 ;If Char is ' '
BEQ issec ; Return Carry Set
CMP #$09 ;If Char < '\t'
BCC isrts ; Return Carry Clear
CMP #$0E ;Else If Char > '\r'
JMP isbcs ; Return Carry Clear Else Return Carry Set
ishex: CMP #$41 ;If Char < 'A'
BCC isdgt ; Check for Digit
CMP #$47 ;Else If Char < 'G'
BCC issec ; Return Carry Set
CMP #$61 ;Else If Char < 'a'
BCC isrts ; Return Carry Clear
CMP #$67 ;Else If Char >= 'g'
JMP isbcs ; Return Carry Clear Else Return Carry Set