mirror of https://github.com/Klaus2m5/VTL02.git
Speedy gonzales update 2
; added inline divide by 10 to prnum:.
; fixed statement delimiter not overriding mismatched
; parentheses.
; line numbers >= 65280 are now reserved for the
; following fast return & goto features.
; added a gosub stack, depth = 16 address words.
; {==...} is a gosub and pushes the return address
; of the next line.
; {#==} is a return and pops the address when the
; result is the special line numer asigned to {=}.
; added a 31 line addresses acronym label array.
; lowercase characters and symbols in the $60-$7e
; range are used to address the array. the array
; is populated with the address of a line when a
; character in the allowed range preceeds the line
; number.
This commit is contained in:
Klaus2m5
parent
ff26f67cf7
commit
fbd001c897
649
vtl02sg.a65
649
vtl02sg.a65
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@ -180,12 +180,32 @@
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; mainloop uses inline code to advance to next
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; sequential program line.
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; find: is now only used for true branches.
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; added statement delimiter allowing multi statement
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; lines. branch to same line is now allowed.
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; added decimal to binary conversion on line entry.
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; added a statement delimiter {;} allowing multi
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; statement lines.
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; branch to same line is now allowed.
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; {?="..."} & unmatched {)} (used for comments) can
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; not be continued.
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; added decimal to binary conversion on line entry
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; avoiding the runtime conversion.
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; abbreviated getting a simple variable in getval:.
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; bypassed setting a simple variable in exec:.
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;
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; added inline divide by 10 to prnum:.
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; fixed statement delimiter not overriding mismatched
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; parentheses.
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; line numbers >= 65280 are now reserved for the
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; following fast return & goto features.
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; added a gosub stack, depth = 16 address words.
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; {==...} is a gosub and pushes the return address
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; of the next line.
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; {#==} is a return and pops the address when the
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; result is the special line numer asigned to {=}.
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; added a 31 line addresses acronym label array.
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; lowercase characters and symbols in the $60-$7e
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; range are used to address the array. the array
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; is populated with the address of a line when a
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; character in the allowed range preceeds the line
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; number.
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;
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;-----------------------------------------------------;
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; VTL02C variables occupy RAM addresses $0080 to $00ff,
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; and are little-endian, in the 6502 tradition.
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@ -203,7 +223,8 @@ at = $80 ; {@}* internal pointer / mem byte
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; VTL02C standard user variable space
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; {A B C .. X Y Z [ \ ] ^ _}
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; VTL02C system variable space
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space = $c0 ; { }* temp / Starting with VTL02B:
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space = $c0 ; { }* gosub stack /
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; Starting with VTL02B:
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; the space character is no
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; longer a valid user variable
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; nor a "valid" binary operator.
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@ -222,21 +243,20 @@ lparen = $d0 ; {(}* old line # / begin sub-exp
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rparen = $d2 ; {)}* temp storage / end sub-exp
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star = $d4 ; {*} pointer to end of free mem
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; $d6 ; {+ , - .} valid variables
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; $fe ; {/} counting 10ms tick timer
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; (1) $fe ; {/} 10ms count up timer
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; Interpreter argument stack space
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arg = $e0 ; {0 1 2 3 4 5 6 7 8 9 :}*
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; Rarely used variables and argument stack overflow
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; $f6 ; {;}* valid user variable /
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; statement separator
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semico = $f6 ; {;}* statement delimiter
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lthan = $f8 ; {<}* user memory byte pointer
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; = $fa ; {=}* valid user variable
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equal = $fa ; {=}* temp / gosub & return addr.
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gthan = $fc ; {>}* temp / call ML subroutine
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ques = $fe ; {?}* temp / terminal i/o
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;
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nulstk = $01ff ; system stack resides in page 1
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; additional configurable variables and operators
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; (1) additional configurable variables and operators
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timr_var = '/' ; 10 ms count up variable
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stmntdlm = ';' ; statement delimiter
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timr_adr = timr_var*2|$80
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;-----------------------------------------------------;
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; Equates for a 48K+ Apple 2 (original, +, e, c, gs)
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;ESC = 27 ; "Cancel current input line" key
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@ -256,10 +276,12 @@ ESC = 27 ; "Cancel current input line" key
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BS = 8 ; "Delete last keypress" key
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OP_OR = '|' ; Bit-wise OR operator
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timr_var = '/' ; 10 ms count up variable
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lblary = $0100 ; array with goto labels
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vtlstck = $0140 ; gosub stack space, 64 bytes
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linbuf = $0200 ; input line buffer
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prgm = $0400 ; VTL02C program grows from here
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himem = $7900 ; ... up to the top of user RAM
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vtl02c = $f900 ; interpreter cold entry point
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himem = $7800 ; ... up to the top of user RAM
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vtl02c = $f800 ; interpreter cold entry point
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; (warm entry point is startok)
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io_area = $bf00 ;configure emulator terminal I/O
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acia_tx = io_area+$f0 ;acia tx data register
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@ -280,11 +302,18 @@ diag = io_area+$fc ;diag reg, bit 7 = exit to mon
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sta star ; {*} -> top of user RAM
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lda #hi(himem)
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sta star+1
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lda #0 ; clear label array & gosub stack
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ldx #95
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reset1:
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sta lblary,x
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dex
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bpl reset1
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sta space ; clear pointer to user stack
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startok:
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sec ; request "OK" message
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; - - - - - - - - - - - - - - - - - - - - - - - - - - ;
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; Start/restart VTL02C command line with program intact
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; 32 bytes
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;
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start:
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cld ; a sensible precaution
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ldx #lo(nulstk)
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@ -301,11 +330,57 @@ user:
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sta lparen
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sta lparen+1
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jsr inln ; input a line from the user
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lda linbuf ; check for line label char
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cmp #$60
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bcc user1
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iny ; skip label char
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user1:
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ldx #pound ; cvbin destination = {#}
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jsr cvbin ; skip line number if exists
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jsr d2b ; convert numbers in line to binary
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jsr cvbin ; does line start with a number?
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beq direct ; no: execute direct statement
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bne stmnt ; no: execute direct statement
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lda lblary+62 ; label array populated ?
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bne user2 ; yes: skip polpulating it
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tya ; no: populate now!
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pha
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lda #lo(prgm)
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sta gthan
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lda #hi(prgm)
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sta gthan+1
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ldaraylp:
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ldy #0
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lda (gthan),y ; is label ?
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cmp #$60
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bcc ldaray1 ; no: skip load
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and #$1f ; make index to label array
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asl a
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tax
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lda gthan ; line address -> array
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sta lblary,x
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lda gthan+1
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sta lblary+1,x
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ldaray1:
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ldy #3 ; add offset to next line
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lda gthan
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ldx gthan+1
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clc
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adc (gthan),y ; add offset
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bcc ldaray2
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inx
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ldaray2:
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sta gthan
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stx gthan+1
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cpx ampr+1 ; end of program ?
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bcc ldaraylp ; no: loop next line
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bne ldaray3
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cmp ampr
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bcc ldaraylp
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ldaray3:
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sty lblary+62 ; mark populated
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pla
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tay
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user2:
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jmp exec
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; - - - - - - - - - - - - - - - - - - - - - - - - - - ;
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; Delete/insert/replace program line or list program
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; 7 bytes
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@ -322,6 +397,9 @@ stmnt:
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; 20 bytes
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list_:
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jsr findln ; find program line >= {#}
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ldx #0
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lda (at,x) ; print label
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jsr outch
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ldx #lparen ; line number for prnum
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jsr prnum ; print the line number
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lda #' ' ; print a space instead of the
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@ -331,98 +409,15 @@ list_:
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bcs list_ ; (always taken)
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jskp2:
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jmp skp2
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;-----------------------------------------------------;
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; The main program execution loop
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; entry: with (cs) via "beq direct" in user:
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; exit: to command line via findln: or "beq start"
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;
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progr:
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; beq eloop0 ; if {#} = 0 then ignore and
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; beq prog_nxt ; no branch - next line
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lda arg ; left side of last eval was {#}?
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cmp #pound
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bne prog_nxt
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lda arg+1
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beq branch
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; ldy lparen+1 ; continue (false branch)
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; ldx lparen ; else did {#} change?
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; cpy pound+1 ; yes: perform a branch, with
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; bne branch ; carry flag conditioned for
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; cpx pound ; the appropriate direction.
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;; beq eloop ; no: execute next line (cs)
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; bne branch
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prog_nxt:
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ldy #2 ; point {@} to next line address
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ldx at+1 ; current line address
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lda at
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clc
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adc (at),y ; {@} low + offset
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bcc prg_n1
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inx ; {@} high + carry
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prg_n1:
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cpx ampr+1 ; exceeds end of program?
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bcc prg_n2 ; no
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bne start ; yes - exit to direct mode
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cmp ampr
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bcs start
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prg_n2: ; (cc)
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stx at+1 ; next line address valid!
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sta at
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ldy #0
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lda (at),y
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sta lparen ; {(} = {#} = current line number
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sta pound
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iny
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lda (at),y
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sta lparen+1
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sta pound+1
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;prg_same: ; from branch to same line
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ldy #3
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direct:
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php ; (cc: program, cs: direct)
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jsr exec ; execute one VTL02C line
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plp
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bcc progr ; if program mode then continue
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lda pound ; if direct mode, did {#} change?
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ora pound+1
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beq jstart2 ; no: restart "OK" prompt
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bne eloop0 ; yes: execute program from {#}
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branch:
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ldy lparen+1 ; execute a VTL02C branch
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ldx lparen
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cpy pound+1 ; perform a branch, with
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bne branch1 ; carry flag conditioned for
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cpx pound ; the appropriate direction.
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; beq prg_same ; is the same line again
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branch1:
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inx ; leave a return address
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bne branch2
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iny
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branch2:
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stx bang ; {!} = {(} + 1 (return ptr)
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sty bang+1
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eloop0:
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rol a
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eor #1 ; complement carry flag
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ror a
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eloop:
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; jsr findln ; find first/next line >= {#}
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jsr find ; inline findln
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bcs jstart2 ; if end then restart "OK" prompt
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sta pound ; {#} = {(}
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stx pound+1 ; end inline
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iny ; skip over the length byte
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bne direct
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jstart2:
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jmp start
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lda lblary+62 ; label array clear ?
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beq skp2 ; then skip clearing it
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lda #0 ; clear label array & gosub stack
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ldx #95
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clr_ls:
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sta lblary,x
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dex
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bpl clr_ls
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sta space ; clear pointer to user stack
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;-----------------------------------------------------;
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; Delete/insert/replace program line and restart the
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; command prompt (no "OK" means success)
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@ -466,18 +461,24 @@ delt2:
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insrt:
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pla
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tax ; x = linbuf offset pointer
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lda linbuf ; push label or blank
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cmp #$60
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bcs insrt2
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lda #' '
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insrt2:
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pha
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lda pound
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pha ; push the new line number on
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lda pound+1 ; the system stack
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pha
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ldy #2
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ldy #3
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cntln:
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inx
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iny ; determine new line length in y
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lda linbuf-1,x ; and push statement string on
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pha ; the system stack
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bne cntln
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cpy #4 ; if empty line then skip the
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cpy #5 ; if empty line then skip the
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bcc jstart ; insertion process
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tax ; x = 0
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tya
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@ -514,7 +515,7 @@ move2:
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dey ; the new line number and store
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sta (at),y ; them in the program gap
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bne move2
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ldy #2
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ldy #3
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txa
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sta (at),y ; store length after line number
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lda gthan
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@ -618,8 +619,9 @@ pro_skp: ; inline skpbyte
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cmp #' '
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beq pro_skp ; end inline
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cmp #';' ; if trailing char is ';' then
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beq execrts ; suppress the \n
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cmp #';' ; if trailing char is not ';'
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bne outnl ; print \n
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rts ; else suppress the \n
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outnl:
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lda #$0d ; \n to terminal
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jmp outch
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@ -646,9 +648,9 @@ exec:
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; beq execrts
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; iny
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lda (at),y ; inline getbyte
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beq execrts ; do nothing with a null statement
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beq execend1 ; do nothing with a null statement
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cmp #')' ; same for a full-line comment
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beq execrts
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beq execend1
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; sty dolr+1 ; save index if arg[{1}] = arg[{0}]
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iny
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cmp #' ' ; is space?
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@ -689,10 +691,44 @@ exec3:
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execend:
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ldy dolr+1 ; restore line index
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pla
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cmp #stmntdlm ; statement delimiter ?
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iny
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cmp #';' ; statement delimiter ?
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beq exec ; continue with next statement
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execrts:
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rts ; end of line
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execend1:
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lda lparen ; direct mode ?
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ora lparen+1
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beq jstart4
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prog_nxt:
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ldy #3 ; point {@} to next line address
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ldx at+1 ; current line address
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lda at
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clc
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adc (at),y ; {@} low + offset
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bcc prg_n1
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inx ; {@} high + carry
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prg_n1:
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cpx ampr+1 ; exceeds end of program?
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bcc prg_n2 ; no
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bne jstart4 ; yes - exit to direct mode
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cmp ampr
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bcs jstart4
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prg_n2: ; (cc)
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stx at+1 ; next line address valid!
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sta at
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ldy #1
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lda (at),y
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sta lparen ; {(} = {#} = current line number
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sta pound
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iny
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lda (at),y
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sta lparen+1
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sta pound+1
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ldy #4
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jmp exec ; loop next line
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jstart4:
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sec
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jmp start
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; special variables including array
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exec_byp:
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ldx #arg ; initialize argument pointer
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@ -704,6 +740,7 @@ exec_gb3: ; inline getbyte + skpbyte
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iny ; skip space +1
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cmp #' ' ; is space?
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beq exec_gb3
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; the code below allows (N+1) instead of (N=N+1)
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; cmp #'=' ; not '=' implies assigning
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; beq exec_gb4 ; variable as target & 1st source
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; ldy dolr+1 ; back up to arg[{1}] = arg[{0}]
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|
@ -717,9 +754,7 @@ exec_gb4:
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bne exec_gb4
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exec_gb5: ; end inline
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cmp #'"' ; yes: print the string with
|
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bne exec2
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jmp prstr ; trailing ';' check & return
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exec2:
|
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beq exec2
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ldx #arg+2 ; point eval to arg[{1}]
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jsr eval ; evaluate right-side in arg[{1}]
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pha
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|
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@ -738,29 +773,55 @@ exec2:
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cpx #gthan ; if {>=...} statement then call
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beq usr ; user-defined ml routine
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cpx #pound ; if {#=...} statement then goto
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; beq goto ; arg[{1}] as line number
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bne exec3
|
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beq goto ; arg[{1}] as line number
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cpx #equal ; if {==...} statement then gosub
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beq gosub ; arg[{1}] as line number
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jmp exec3 ; defaults to store variable
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exec2:
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jsr prstr ; trailing ';' check & return
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jmp execend1
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gosub:
|
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lda lparen ; is direct mode ?
|
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ora lparen+1
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beq gosub3 ; return to commandline
|
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lda at ; calculate next line address
|
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ldy #3
|
||||
clc
|
||||
adc (at),y ; add to offset
|
||||
tax
|
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lda #0
|
||||
adc at+1
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||||
cmp ampr+1 ; address beyond end of program ?
|
||||
bcc gosub2
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bne gosub3
|
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cpx ampr
|
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bcc gosub2
|
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gosub3:
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lda #0 ; then return ends program
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tax
|
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gosub2:
|
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ldy space ; load VTL user stack pointer
|
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sta vtlstck,y ; push high
|
||||
txa
|
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sta vtlstck+1,y ; push low
|
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iny
|
||||
iny
|
||||
tya
|
||||
and #$1f ; wrap around upper linimt
|
||||
sta space ; save VTL user stack pointer
|
||||
lda #pound ; point to standard line #
|
||||
sta arg
|
||||
ldy #0 ; restore Y
|
||||
lda arg+2
|
||||
|
||||
goto:
|
||||
tax ; save line # low
|
||||
ora arg+3 ; fall through ?
|
||||
bne goto1
|
||||
sta arg ; invalidate goto {#}
|
||||
beq execend
|
||||
goto1:
|
||||
pla ; true goto
|
||||
cpx lparen ; is same line ?
|
||||
bne goto2
|
||||
lda arg+3
|
||||
cmp lparen+1
|
||||
bne goto2
|
||||
ldy #3 ; start over
|
||||
jmp exec
|
||||
goto2:
|
||||
tya ; different line
|
||||
pha ; invalidate {;}
|
||||
txa ; restore line # low
|
||||
jmp exec3 ; store new line in {#}
|
||||
; sta arg ; invalidate goto {#}
|
||||
jmp execend
|
||||
|
||||
usr:
|
||||
tax ; jump to user ml routine with
|
||||
lda arg+3 ; arg[{1}] in a:x (MSB:LSB)
|
||||
|
|
@ -774,33 +835,118 @@ poke:
|
|||
joutch:
|
||||
jsr outch ; print character
|
||||
jmp execend
|
||||
;-----------------------------------------------------;
|
||||
; {?=...} handler; called by exec:
|
||||
; 2 bytes
|
||||
prnum0:
|
||||
ldx #arg+2 ; x -> arg[{1}], fall through
|
||||
jsr prnum
|
||||
jmp execend
|
||||
|
||||
goto1:
|
||||
lda lparen ; set {!} as return line #
|
||||
sta bang
|
||||
lda lparen+1
|
||||
sta bang+1
|
||||
inc bang ; + 1
|
||||
bne goto11
|
||||
inc bang+1
|
||||
goto11:
|
||||
pla ; true goto
|
||||
ldy arg+3 ; is physical address pointer ?
|
||||
cpy #$ff
|
||||
beq goto3
|
||||
ora lparen ; direct mode ?
|
||||
beq goto12
|
||||
cpy lparen+1 ; set carry flag for find
|
||||
bne goto2
|
||||
cpx lparen
|
||||
bne goto2
|
||||
ldy #4 ; same line - start over
|
||||
jmp exec
|
||||
goto5:
|
||||
txa ; build address to label array
|
||||
and #$1f
|
||||
asl a
|
||||
tay
|
||||
lda lblary,y ; load address from array
|
||||
sta at
|
||||
iny
|
||||
lda lblary,y ; load address from array
|
||||
sta at+1
|
||||
bne goto7 ; if initialized
|
||||
jstart3:
|
||||
sec ; print OK
|
||||
jmp start
|
||||
goto12:
|
||||
clc ; from start of prog
|
||||
goto2:
|
||||
; tya ; different line
|
||||
; pha ; invalidate {;}
|
||||
; txa ; restore line # low
|
||||
; jmp exec3 ; store new line in {#}
|
||||
|
||||
stx pound ; store target
|
||||
sty pound+1
|
||||
jsr find
|
||||
bcs jstart3 ; end of program
|
||||
sta pound
|
||||
stx pound+1
|
||||
iny ; y = 3
|
||||
jmp exec
|
||||
|
||||
goto3:
|
||||
cpx #'=' ; from stack ?
|
||||
bne goto5 ; else is label
|
||||
ldy space ; load stack pointer
|
||||
bne goto4
|
||||
ldy #$20 ; wrap around
|
||||
goto4:
|
||||
dey ; load new address from stack
|
||||
lda vtlstck,y
|
||||
sta at
|
||||
dey
|
||||
lda vtlstck,y
|
||||
beq jstart3 ; if not initialized
|
||||
sta at+1
|
||||
sty space ; save stack pointer
|
||||
goto7:
|
||||
ldy #1 ; load line #
|
||||
lda (at),y
|
||||
sta lparen
|
||||
sta pound
|
||||
iny
|
||||
lda (at),y
|
||||
sta lparen+1
|
||||
sta pound+1
|
||||
ldy #4
|
||||
jmp exec
|
||||
; - - - - - - - - - - - - - - - - - - - - - - - - - - ;
|
||||
; Print an unsigned decimal number (0..65535) in var[x]
|
||||
; entry: var[x] = number to print
|
||||
; uses: div:, outch:, var[x+2], saves original {%}
|
||||
; exit: var[x] = 0, var[x+2] = 10
|
||||
; 43 bytes
|
||||
; uses: outch:, gthan
|
||||
; exit: var[x] = 0
|
||||
;
|
||||
prnum:
|
||||
lda remn
|
||||
pha ; save {%}
|
||||
lda remn+1
|
||||
pha
|
||||
lda #0 ; null delimiter for print
|
||||
pha
|
||||
sta 3,x
|
||||
lda #10 ; divisor = 10
|
||||
sta 2,x ; repeat {
|
||||
prnum2:
|
||||
jsr div ; divide var[x] by 10
|
||||
lda remn
|
||||
ora #'0' ; convert remainder to ASCII
|
||||
prnum2: ; divide var[x] by 10
|
||||
lda #0
|
||||
sta gthan+1 ; clr BCD
|
||||
lda #16
|
||||
sta gthan ; {>} = loop counter
|
||||
prdiv1:
|
||||
asl 0,x ; var[x] is gradually replaced
|
||||
rol 1,x ; with the quotient
|
||||
rol gthan+1 ; BCD result is gradually replaced
|
||||
lda gthan+1 ; with the remainder
|
||||
sec
|
||||
sbc #10 ; partial BCD >= 10 ?
|
||||
bcc prdiv2
|
||||
sta gthan+1 ; yes: update the partial result
|
||||
inc 0,x ; set low bit in partial quotient
|
||||
prdiv2:
|
||||
dec gthan
|
||||
bne prdiv1 ; loop 16 times
|
||||
lda gthan+1
|
||||
ora #'0' ; convert BCD result to ASCII
|
||||
pha ; stack digits in ascending
|
||||
lda 0,x ; order ('0' for zero)
|
||||
ora 1,x
|
||||
|
|
@ -810,10 +956,6 @@ prnum3:
|
|||
jsr outch ; print digits in descending
|
||||
pla ; order until delimiter is
|
||||
bne prnum3 ; encountered
|
||||
pla
|
||||
sta remn+1 ; restore {%}
|
||||
pla
|
||||
sta remn
|
||||
rts
|
||||
;-----------------------------------------------------;
|
||||
; Evaluate a (hopefully) valid VTL02C expression at
|
||||
|
|
@ -853,9 +995,9 @@ notdn:
|
|||
eval_gb: ; inline getbyte
|
||||
lda (at),y
|
||||
beq evalrts
|
||||
iny ; skip over any space char(s)
|
||||
cmp #stmntdlm ; statement delimiter ?
|
||||
cmp #';' ; statement delimiter ?
|
||||
beq evalrts
|
||||
iny ; skip over any space char(s)
|
||||
cmp #' ' ; is space?
|
||||
beq eval_gb ; end inline
|
||||
|
||||
|
|
@ -874,8 +1016,11 @@ getval:
|
|||
; sta 1,x
|
||||
lda (at),y ; get variable or constant
|
||||
bpl getvar
|
||||
beq getrts ; safety exit - end of banana
|
||||
; cmp ';'
|
||||
; beq getrts
|
||||
iny
|
||||
; cmp #' ' ; skip space
|
||||
; beq getval
|
||||
; get constant
|
||||
cmp #$fd ; constant type ?
|
||||
bcs getword
|
||||
|
|
@ -907,6 +1052,9 @@ clrhigh:
|
|||
rts
|
||||
; get variable
|
||||
getvar:
|
||||
beq getrts ; safety exit - end of banana
|
||||
cmp ';'
|
||||
beq getrts
|
||||
iny
|
||||
cmp #'@' ; peek?
|
||||
bcs getv_byp ; bypass variables >= @
|
||||
|
|
@ -916,12 +1064,20 @@ getvar:
|
|||
beq getary
|
||||
cmp #'(' ; sub-expression?
|
||||
beq eval ; yes: evaluate it recursively
|
||||
cmp #'=' ; return after gosub
|
||||
beq gotomark
|
||||
cmp #'$' ; user char input?
|
||||
beq in_chr
|
||||
cmp #'?' ; user line input?
|
||||
beq in_val
|
||||
getv_byp:
|
||||
beq peek
|
||||
cmp #$60 ; line # variable
|
||||
bcs gotomark
|
||||
|
||||
; first set var[x] to the named variable's address,
|
||||
; then replace that address with the variable's actual
|
||||
; value before returning
|
||||
|
||||
sty dolr ; get simple variable
|
||||
asl a
|
||||
|
|
@ -936,9 +1092,6 @@ getv_byp:
|
|||
ldy dolr
|
||||
rts
|
||||
|
||||
; first set var[x] to the named variable's address,
|
||||
; then replace that address with the variable's actual
|
||||
; value before returning
|
||||
getary: ; get array variable
|
||||
jsr convp_array
|
||||
lda (0,x)
|
||||
|
|
@ -965,6 +1118,12 @@ peek: ; memory access?
|
|||
sta 1,x
|
||||
rts
|
||||
|
||||
gotomark: ; special line # 65280 +
|
||||
sta 0,x ; low = stack/label
|
||||
lda #$ff
|
||||
sta 1,x ; 65280
|
||||
rts
|
||||
|
||||
in_chr: ; user char input?
|
||||
jsr inch ; input one char
|
||||
sta 0,x
|
||||
|
|
@ -980,8 +1139,15 @@ in_val: ; user line input
|
|||
lda at+1
|
||||
pha
|
||||
jsr inln ; input expression from user
|
||||
lda linbuf ; empty ?
|
||||
bne in_val2
|
||||
sta 0,x ; defaults to 0
|
||||
sta 1,x
|
||||
beq in_val3
|
||||
in_val2:
|
||||
jsr d2b ; convert numbers in line to binary
|
||||
jsr eval ; evaluate, var[x] = result
|
||||
in_val3:
|
||||
pla
|
||||
sta at+1
|
||||
pla
|
||||
|
|
@ -1308,49 +1474,55 @@ cvbin3:
|
|||
;-----------------------------------------------------;
|
||||
; Accept input line from user and store it in linbuf,
|
||||
; zero-terminated (allows very primitive edit/cancel)
|
||||
; entry: (jsr to inln or newln, not inln6)
|
||||
; entry: (jsr to inln or newln)
|
||||
; used by: user:, getval:
|
||||
; uses: inch:, outnl:, linbuf, {@}
|
||||
; exit: @[y] -> linbuf
|
||||
; 42 bytes
|
||||
inln6:
|
||||
cmp #ESC ; escape?
|
||||
beq newln ; yes: discard entire line
|
||||
iny ; line limit exceeded?
|
||||
bpl inln2 ; no: keep going
|
||||
newln:
|
||||
;
|
||||
;newln:
|
||||
; jsr outnl ; yes: discard entire line
|
||||
ldy #0
|
||||
inln4:
|
||||
jsr outcr
|
||||
lda erase_line,y
|
||||
beq inln
|
||||
jsr outch
|
||||
iny
|
||||
bpl inln4
|
||||
inln:
|
||||
ldy #lo(linbuf); entry point: start a fresh line
|
||||
sty at ; {@} -> input line buffer
|
||||
ldy #hi(linbuf)
|
||||
sty at+1
|
||||
ldy #1
|
||||
inln5:
|
||||
dey
|
||||
bmi newln
|
||||
inln2:
|
||||
ldy #0
|
||||
inlnlp: ; main loop
|
||||
jsr inch ; get (and echo) one key press
|
||||
cmp #BS ; backspace?
|
||||
beq inln5 ; yes: delete previous char
|
||||
beq inlnbs ; yes: delete previous char
|
||||
cmp #ESC ; escape?
|
||||
beq inlnesc ; yes: discard entire line
|
||||
cmp #$0d ; cr?
|
||||
bne inln3
|
||||
lda #0 ; yes: replace with null
|
||||
inln3:
|
||||
beq inlncr
|
||||
cmp #' ' ; do not store ctrl keys
|
||||
bcc inlnlp
|
||||
sta (at),y ; put key in linbuf
|
||||
bne inln6 ; continue if not null
|
||||
iny
|
||||
bpl inlnlp ; loop if < len(linbuf)
|
||||
lda #BS ; hold at end of buffer
|
||||
jsr outch
|
||||
inlnbs:
|
||||
dey ; backspace
|
||||
bpl inlnlp
|
||||
lda #13 ; hold at begin of buffer
|
||||
jsr outch
|
||||
iny
|
||||
bpl inlnlp
|
||||
inlncr:
|
||||
lda #0 ; cr - mark end of line
|
||||
sta (at),y
|
||||
tay ; y = 0
|
||||
rts
|
||||
erase_line:
|
||||
db ESC,"[K",0
|
||||
inlnesc:
|
||||
cpy #0 ; escape - reverse all input
|
||||
beq inlnlp
|
||||
lda #BS
|
||||
inlnesc1:
|
||||
jsr outch
|
||||
dey
|
||||
bne inlnesc1
|
||||
beq inlnlp
|
||||
;-----------------------------------------------------;
|
||||
; Find the first/next stored program line >= {#}
|
||||
; entry: (cc): start search at program beginning
|
||||
|
|
@ -1358,8 +1530,8 @@ erase_line:
|
|||
; ({@} -> beginning of current line)
|
||||
; used by: skp2:, findln:
|
||||
; uses: prgm, {@ # & (}
|
||||
; exit: (cs): {@}, x:a and {(} undefined, y = 2
|
||||
; (cc): {@} -> beginning of found line, y = 2,
|
||||
; exit: (cs): {@}, x:a and {(} undefined, y = 3
|
||||
; (cc): {@} -> beginning of found line, y = 3,
|
||||
; x:a = {(} = actual found line number
|
||||
; 62 bytes
|
||||
find:
|
||||
|
|
@ -1367,7 +1539,7 @@ find:
|
|||
lda #lo(prgm)
|
||||
bcc find1st ; cc: search begins at first line
|
||||
ldx at+1
|
||||
ldy #2
|
||||
ldy #3
|
||||
findnxt:
|
||||
lda at
|
||||
cmp ampr
|
||||
|
|
@ -1383,7 +1555,7 @@ find1st:
|
|||
stx at+1
|
||||
find5:
|
||||
sta at
|
||||
ldy #0
|
||||
ldy #1
|
||||
lda (at),y
|
||||
sta lparen ; {(} = current line number
|
||||
cmp pound ; (invalid if {@} >= {&}, but
|
||||
|
|
@ -1410,22 +1582,24 @@ findrts:
|
|||
; if high byte is $00 then 2 bytes $FD $01-$FF
|
||||
;
|
||||
d2b:
|
||||
php
|
||||
txa ; save pointer to arg
|
||||
pha
|
||||
tya
|
||||
pha
|
||||
lda #0 ; statement position counter
|
||||
sta dolr+1
|
||||
d2blp: ; main loop
|
||||
inc dolr+1 ; next var, operator or constant
|
||||
ldx #space ; cvbin converts to space var
|
||||
ldx #equal ; cvbin converts to equal var
|
||||
jsr cvbin ; convert if decimal
|
||||
beq d2b1 ; if not a constant
|
||||
d2b6:
|
||||
; sty ques+1 ; save to continue later
|
||||
ldx ques ; x = y before conversion
|
||||
inc ques ; always uses at least 1 byte
|
||||
lda space+1 ; is < 125 ?
|
||||
lda equal+1 ; is < 125 ?
|
||||
bne d2b2
|
||||
lda space
|
||||
lda equal
|
||||
cmp #125
|
||||
bcs d2b2
|
||||
ora #$80 ; < 125 = 1 byte
|
||||
|
|
@ -1435,15 +1609,15 @@ d2b2: ; >= 125 = 2 or 3 bytes
|
|||
inc ques ; uses at least 2 bytes
|
||||
lda #$ff ; mark word constant
|
||||
sta ques+1
|
||||
lda space ; constant low
|
||||
lda equal ; constant low
|
||||
bne d2b8
|
||||
dec ques+1 ; clear bit 0 in marker = $FE
|
||||
lda space+1 ; store only constant high
|
||||
lda equal+1 ; store only constant high
|
||||
sta linbuf+1,x
|
||||
bne d2b19
|
||||
d2b8:
|
||||
sta linbuf+1,x ; store constant low
|
||||
lda space+1 ; constant high
|
||||
lda equal+1 ; constant high
|
||||
bne d2b9
|
||||
dec ques+1 ; clear bit 1 in marker = $FD
|
||||
dec ques+1
|
||||
|
|
@ -1470,40 +1644,36 @@ d2b7:
|
|||
d2b1:
|
||||
lda linbuf,y ; is end of line ?
|
||||
beq d2bex ; exit
|
||||
; jsr outch ; debug
|
||||
iny
|
||||
; pha
|
||||
cmp #stmntdlm ; new statement starts
|
||||
cmp #';' ; new statement starts
|
||||
bne d2b10
|
||||
; lda dolr+1 ; in operator position (even)
|
||||
; and #1
|
||||
; bne d2b10
|
||||
lda #0
|
||||
sta dolr+1 ; clear position pointer
|
||||
; pla
|
||||
beq d2blp ; loop next
|
||||
d2b10:
|
||||
; pla
|
||||
; cmp #'(' ; neither var nor op
|
||||
; beq d2b11
|
||||
; cmp #')' ; neither var nor op
|
||||
; bne d2b12
|
||||
;d2b11:
|
||||
; inc dolr+1 ; stays odd (var) or even (op)
|
||||
;d2blp1
|
||||
; jmp d2blp
|
||||
d2b12:
|
||||
cmp #$60 ; prevent lower case on left side
|
||||
bcc d2b11
|
||||
ldx dolr+1 ; is target variable ?
|
||||
cpx #1
|
||||
bne d2blp
|
||||
and #$5f ; convert to upper case
|
||||
sta linbuf-1,y
|
||||
bne jd2blp
|
||||
d2b11:
|
||||
cmp #'"' ; potential string ?
|
||||
bne d2blp
|
||||
bne jd2blp
|
||||
lda dolr+1 ; exit on 3rd position (is string)
|
||||
cmp #3
|
||||
bne d2blp ; loop if not
|
||||
bne jd2blp ; loop if not
|
||||
d2bex:
|
||||
; jsr outnl ;debug
|
||||
pla ; restore pointer to arg
|
||||
tay
|
||||
pla
|
||||
tax
|
||||
ldy #0
|
||||
plp
|
||||
rts
|
||||
jd2blp:
|
||||
jmp d2blp
|
||||
;-----------------------------------------------------;
|
||||
; Fetch a byte at @[y], ignoring space characters
|
||||
; 10 bytes
|
||||
|
|
@ -1599,16 +1769,22 @@ skip_esc_discard:
|
|||
cpy #1
|
||||
bne inch ; discard escape sequence
|
||||
lda #27 ; escape only - send to vtl
|
||||
rts
|
||||
; ldy dolr
|
||||
; rts
|
||||
skip_esc_no
|
||||
ldy dolr ; restore y reg
|
||||
inch2:
|
||||
and #$7f ; ensure char is positive ascii
|
||||
; cmp #$03 ; ctrl-C?
|
||||
jsr test_abort
|
||||
jmp outch ; no: echo to terminal
|
||||
istart:
|
||||
jmp start ; yes: abort to "OK" prompt
|
||||
cmp #BS ; only echo printable, bs & cr
|
||||
beq outch
|
||||
cmp #13
|
||||
beq outch
|
||||
cmp #' '
|
||||
bcs outch
|
||||
sec
|
||||
rts
|
||||
|
||||
test_abort:
|
||||
cmp #3 ; is ctrl-c
|
||||
|
|
@ -1617,10 +1793,13 @@ test_abort:
|
|||
beq abort ; yes: exit to monitor
|
||||
rts
|
||||
abort:
|
||||
jsr outcr
|
||||
lda #$80 ; exit to monitor
|
||||
sta diag
|
||||
lda #ESC ; escape after continue
|
||||
rts
|
||||
istart:
|
||||
jmp start ; yes: abort to "OK" prompt
|
||||
; - - - - - - - - - - - - - - - - - - - - - - - - - - ;
|
||||
; Print ascii char in a to stdout, (cs)
|
||||
;
|
||||
|
|
@ -1647,20 +1826,20 @@ skip_bs:
|
|||
;
|
||||
IRQ_10ms:
|
||||
pha
|
||||
inc timr_adr ; increment the variable {/}
|
||||
inc timr_adr ; increment the variable {/}
|
||||
bne IRQ_exit
|
||||
inc timr_adr+1
|
||||
IRQ_exit:
|
||||
lda #1 ; clear interrupt flag
|
||||
lda #1 ; clear interrupt flag
|
||||
sta timr_fl
|
||||
pla
|
||||
rti
|
||||
; Start the timer prior to VTL
|
||||
IRQ_start:
|
||||
lda #1 ; set bit 0 (10ms tick)
|
||||
sta timr_ie ; -> interrupt enable
|
||||
lda #1 ; set bit 0 (10ms tick)
|
||||
sta timr_ie ; -> interrupt enable
|
||||
cli
|
||||
jmp vtl02c ; continue cold start
|
||||
jmp vtl02c ; continue cold start
|
||||
;-----------------------------------------------------;
|
||||
org $fffc
|
||||
dw IRQ_start ; reset vector -> cold start
|
||||
|
|
|
|||
Loading…
Reference in New Issue