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VTL02
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Speedy Gonzales update 3 

merged oper: and exec:
added braces as shift operator
added check for ctrl-c and ctrl-z to goto to allow user to escape from
an unintentional loop
This commit is contained in:
Klaus2m5 2015-11-20 19:00:15 +01:00
parent fbd001c897
commit 217281b671
1 changed files with 214 additions and 222 deletions
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436
vtl02sg.a65
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@ -167,31 +167,23 @@
; programming principles remained at low priority. ; programming principles remained at low priority.
; ;
; VTL02 for the 2m5 emulated 6502 SBC ; VTL02 for the 2m5 emulated 6502 SBC
; - released: 20-nov-2015
; - codename: speedy Gonzales ; - codename: speedy Gonzales
; - based on VTL02C, changes by Klaus2m5 ; - based on VTL02C, changes by Klaus2m5
; ;
; added a timer variable {/} with 10ms increments ; added a timer variable {/} with 10ms increments.
; required atomic variable fetch & store. ;
; replaced some jsr calls with inline code ; added braces as shift operators.
; for skpbyte:, getbyte:, plus:, minus:. ; A}B shifts A by B bits to the right.
; replaced cvbin calls to mul: & plus: with custom ; A{B shifts A by B bits to the left.
; inline multiply by 10 & digit adder. ; result is unpredictable if B > 16
; removed simulation from startup of eval:. ;
; mainloop uses inline code to advance to next
; sequential program line.
; find: is now only used for true branches.
; added a statement delimiter {;} allowing multi ; added a statement delimiter {;} allowing multi
; statement lines. ; statement lines.
; branch to same line is now allowed. ; branch to same line is now allowed.
; {?="..."} & unmatched {)} (used for comments) can ; {?="..."} & unmatched {)} (used for comments) can
; not be continued. ; not be continued.
; added decimal to binary conversion on line entry ;
; avoiding the runtime conversion.
; abbreviated getting a simple variable in getval:.
; bypassed setting a simple variable in exec:.
; added inline divide by 10 to prnum:.
; fixed statement delimiter not overriding mismatched
; parentheses.
; line numbers >= 65280 are now reserved for the ; line numbers >= 65280 are now reserved for the
; following fast return & goto features. ; following fast return & goto features.
; added a gosub stack, depth = 16 address words. ; added a gosub stack, depth = 16 address words.
@ -206,6 +198,45 @@
; character in the allowed range preceeds the line ; character in the allowed range preceeds the line
; number. ; number.
; ;
; example (prints the first 1000 prime numbers):
; 10 /=0;Q=d;V=5;U=25;X=1000
; 20 N=2;==b
; 30 N=N+1;==b
; 40 N=N+2;==b
; a100 N=N+2;==b
; 120 N=N+4;==b
; 150 #=a
; b200 #=N<U[Q;Q=c;V=V+2;U=V*V
; c300 D=5
; e310 A=N/D;#=%]=;D=D+2;#=D>V[d
; 320 A=N/D;#=%]=;D=D+4;#=D<V[e
; d400 ?=N;?=""
; 420 X=X-1;#=X[=
; 435 ?="Execution time: ";
; 445 ?=//100;$=46;#=%>10[465;?=0
; 465 ?=%;?=" seconds"
;
; internal changes:
; added required atomic variable fetch & store.
; replaced some jsr calls with inline code
; for skpbyte:, getbyte:, plus:, minus:.
; replaced cvbin calls to mul: & plus: with custom
; inline multiply by 10 & digit adder.
; removed simulation from startup of eval:.
; mainloop uses inline code to advance to next
; sequential program line.
; find: is now only used for true branches.
; added decimal to binary conversion on line entry
; avoiding the runtime conversion.
; abbreviated getting a simple variable in getval:.
; bypassed setting a simple variable in exec:.
; added inline divide by 10 to prnum:.
; fixed statement delimiter not overriding mismatched
; parentheses.
; merged oper: into getval: and progr: into exec:
; added a check for ctrl-c & ctrl-z during goto to
; allow user escape from a loop.
;
;-----------------------------------------------------; ;-----------------------------------------------------;
; VTL02C variables occupy RAM addresses $0080 to $00ff, ; VTL02C variables occupy RAM addresses $0080 to $00ff,
; and are little-endian, in the 6502 tradition. ; and are little-endian, in the 6502 tradition.
@ -223,15 +254,13 @@ at = $80 ; {@}* internal pointer / mem byte
; VTL02C standard user variable space ; VTL02C standard user variable space
; {A B C .. X Y Z [ \ ] ^ _} ; {A B C .. X Y Z [ \ ] ^ _}
; VTL02C system variable space ; VTL02C system variable space
space = $c0 ; { }* gosub stack / space = $c0 ; { }* gosub & return stack pointer
; Starting with VTL02B: ; Starting with VTL02B:
; the space character is no ; the space character is no longer a valid user
; longer a valid user variable ; variable nor a "valid" binary operator. It is
; nor a "valid" binary operator. ; now only significant as a numeric constant
; It is now only significant as a ; terminator and as a place-holder in strings
; numeric constant terminator and ; and program listings.
; as a place-holder in strings
; and program listings.
bang = $c2 ; {!} return line number bang = $c2 ; {!} return line number
quote = $c4 ; {"} user ml subroutine vector quote = $c4 ; {"} user ml subroutine vector
pound = $c6 ; {#} current line number pound = $c6 ; {#} current line number
@ -239,17 +268,18 @@ dolr = $c8 ; {$}* temp storage / char i/o
remn = $ca ; {%} remainder of last division remn = $ca ; {%} remainder of last division
ampr = $cc ; {&} pointer to start of array ampr = $cc ; {&} pointer to start of array
tick = $ce ; {'} pseudo-random number tick = $ce ; {'} pseudo-random number
lparen = $d0 ; {(}* old line # / begin sub-exp lparen = $d0 ; {(}* temp line # / begin sub-exp
rparen = $d2 ; {)}* temp storage / end sub-exp rparen = $d2 ; {)}* temp storage / end sub-exp
star = $d4 ; {*} pointer to end of free mem star = $d4 ; {*} pointer to end of free mem
; $d6 ; {+ , - .} valid variables ; $d6 ; {+ , - .} valid variables
; (1) $fe ; {/} 10ms count up timer ; (1) $fe ; {/} 10ms count up timer
; Interpreter argument stack space ; Interpreter argument stack space
arg = $e0 ; {0 1 2 3 4 5 6 7 8 9 :}* arg = $e0 ; {0 1 2 3 4 5 6 7 8 9}*
; Rarely used variables and argument stack overflow ; Rarely used variables and argument stack overflow
; = $f4 ; {:}* array variable header
semico = $f6 ; {;}* statement delimiter semico = $f6 ; {;}* statement delimiter
lthan = $f8 ; {<}* user memory byte pointer lthan = $f8 ; {<}* user memory byte pointer
equal = $fa ; {=}* temp / gosub & return addr. equal = $fa ; {=}* temp / gosub & return stack
gthan = $fc ; {>}* temp / call ML subroutine gthan = $fc ; {>}* temp / call ML subroutine
ques = $fe ; {?}* temp / terminal i/o ques = $fe ; {?}* temp / terminal i/o
; ;
@ -275,11 +305,10 @@ timr_adr = timr_var*2|$80
ESC = 27 ; "Cancel current input line" key ESC = 27 ; "Cancel current input line" key
BS = 8 ; "Delete last keypress" key BS = 8 ; "Delete last keypress" key
OP_OR = '|' ; Bit-wise OR operator OP_OR = '|' ; Bit-wise OR operator
timr_var = '/' ; 10 ms count up variable
lblary = $0100 ; array with goto labels lblary = $0100 ; array with goto labels
vtlstck = $0140 ; gosub stack space, 64 bytes vtlstck = $0140 ; gosub stack space, 64 bytes
linbuf = $0200 ; input line buffer linbuf = $0200 ; input line buffer
prgm = $0400 ; VTL02C program grows from here prgm = $0280 ; VTL02C program grows from here
himem = $7800 ; ... up to the top of user RAM himem = $7800 ; ... up to the top of user RAM
vtl02c = $f800 ; interpreter cold entry point vtl02c = $f800 ; interpreter cold entry point
; (warm entry point is startok) ; (warm entry point is startok)
@ -293,7 +322,7 @@ diag = io_area+$fc ;diag reg, bit 7 = exit to mon
org vtl02c org vtl02c
;-----------------------------------------------------; ;-----------------------------------------------------;
; Initialize program area pointers and start VTL02C ; Initialize program area pointers and start VTL02C
; 17 bytes ;
lda #lo(prgm) lda #lo(prgm)
sta ampr ; {&} -> empty program sta ampr ; {&} -> empty program
lda #hi(prgm) lda #hi(prgm)
@ -327,8 +356,8 @@ start:
jsr outnl jsr outnl
user: user:
lda #0 ; last line # = direct mode lda #0 ; last line # = direct mode
sta lparen sta pound
sta lparen+1 sta pound+1
jsr inln ; input a line from the user jsr inln ; input a line from the user
lda linbuf ; check for line label char lda linbuf ; check for line label char
cmp #$60 cmp #$60
@ -339,6 +368,7 @@ user1:
jsr cvbin ; skip line number if exists jsr cvbin ; skip line number if exists
jsr d2b ; convert numbers in line to binary jsr d2b ; convert numbers in line to binary
bne stmnt ; no: execute direct statement bne stmnt ; no: execute direct statement
; populate the acronym label array
lda lblary+62 ; label array populated ? lda lblary+62 ; label array populated ?
bne user2 ; yes: skip polpulating it bne user2 ; yes: skip polpulating it
tya ; no: populate now! tya ; no: populate now!
@ -380,10 +410,10 @@ ldaray3:
pla pla
tay tay
user2: user2:
jmp exec jmp exec ; execute a direct mode statement
; - - - - - - - - - - - - - - - - - - - - - - - - - - ; ; - - - - - - - - - - - - - - - - - - - - - - - - - - ;
; Delete/insert/replace program line or list program ; Delete/insert/replace program line or list program
; 7 bytes ;
stmnt: stmnt:
clc clc
lda pound lda pound
@ -394,7 +424,7 @@ stmnt:
; entry: Carry must be clear ; entry: Carry must be clear
; uses: findln:, outch:, prnum:, prstr:, {@ ( )} ; uses: findln:, outch:, prnum:, prstr:, {@ ( )}
; exit: to command line via findln: ; exit: to command line via findln:
; 20 bytes ;
list_: list_:
jsr findln ; find program line >= {#} jsr findln ; find program line >= {#}
ldx #0 ldx #0
@ -423,7 +453,7 @@ clr_ls:
; command prompt (no "OK" means success) ; command prompt (no "OK" means success)
; entry: Carry must be clear ; entry: Carry must be clear
; uses: find:, start:, linbuf, {@ > # & * (} ; uses: find:, start:, linbuf, {@ > # & * (}
; 151 bytes ;
skp2: skp2:
tya ; save linbuf offset pointer tya ; save linbuf offset pointer
pha pha
@ -606,13 +636,8 @@ prmsg1:
prmsg2: prmsg2:
tax ; save closing delimiter tax ; save closing delimiter
jsr inkey ; any key = pause/resume? jsr inkey ; any key = pause/resume?
; patch - remove garbage output when halting print
; bcc prout ; no: proceed
; jsr inch ; yes: wait for another key
;prout:
txa ; retrieve closing delimiter txa ; retrieve closing delimiter
beq outnl ; always \n after null delimiter beq outnl ; always \n after null delimiter
; jsr skpbyte ; skip over the delimiter
pro_skp: ; inline skpbyte pro_skp: ; inline skpbyte
iny iny
lda (at),y lda (at),y
@ -626,7 +651,8 @@ outnl:
lda #$0d ; \n to terminal lda #$0d ; \n to terminal
jmp outch jmp outch
;-----------------------------------------------------; ;-----------------------------------------------------;
; Execute a (hopefully) valid VTL02C statement at @[y] ; Execute (hopefully) valid VTL02C statements at @[y]
; exec: will continue until drop to direct mode
; entry: @[y] -> left-side of statement ; entry: @[y] -> left-side of statement
; uses: nearly everything ; uses: nearly everything
; exit: note to machine language subroutine {>=...} ; exit: note to machine language subroutine {>=...}
@ -639,18 +665,12 @@ outnl:
; operator, the statement will execute as {?="...}, ; operator, the statement will execute as {?="...},
; regardless of the variable named on the left side ; regardless of the variable named on the left side
; ;
;execrts1:
; rts
exec: exec:
; jsr getbyte ; fetch left-side variable name
; beq execrts ; do nothing with a null statement
; cmp #')' ; same for a full-line comment
; beq execrts
; iny
lda (at),y ; inline getbyte lda (at),y ; inline getbyte
beq execend1 ; do nothing with a null statement beq execend1 ; do nothing with a null statement
cmp #')' ; same for a full-line comment cmp #')' ; same for a full-line comment
beq execend1 beq execend1
; the code below allows (N+1) instead of (N=N+1)
; sty dolr+1 ; save index if arg[{1}] = arg[{0}] ; sty dolr+1 ; save index if arg[{1}] = arg[{0}]
iny iny
cmp #' ' ; is space? cmp #' ' ; is space?
@ -695,8 +715,8 @@ execend:
cmp #';' ; statement delimiter ? cmp #';' ; statement delimiter ?
beq exec ; continue with next statement beq exec ; continue with next statement
execend1: execend1:
lda lparen ; direct mode ? lda pound ; direct mode ?
ora lparen+1 ora pound+1
beq jstart4 beq jstart4
prog_nxt: prog_nxt:
ldy #3 ; point {@} to next line address ldy #3 ; point {@} to next line address
@ -717,11 +737,9 @@ prg_n2: ; (cc)
sta at sta at
ldy #1 ldy #1
lda (at),y lda (at),y
sta lparen ; {(} = {#} = current line number sta pound ; {#} = current line number
sta pound
iny iny
lda (at),y lda (at),y
sta lparen+1
sta pound+1 sta pound+1
ldy #4 ldy #4
jmp exec ; loop next line jmp exec ; loop next line
@ -733,8 +751,6 @@ jstart4:
exec_byp: exec_byp:
ldx #arg ; initialize argument pointer ldx #arg ; initialize argument pointer
jsr convp ; arg[{0}] -> left-side variable jsr convp ; arg[{0}] -> left-side variable
; jsr getbyte ; skip over assignment operator
; jsr skpbyte ; is right-side a literal string?
exec_gb3: ; inline getbyte + skpbyte exec_gb3: ; inline getbyte + skpbyte
lda (at),y lda (at),y
iny ; skip space +1 iny ; skip space +1
@ -782,8 +798,8 @@ exec2:
jmp execend1 jmp execend1
gosub: gosub:
lda lparen ; is direct mode ? lda pound ; is direct mode ?
ora lparen+1 ora pound+1
beq gosub3 ; return to commandline beq gosub3 ; return to commandline
lda at ; calculate next line address lda at ; calculate next line address
ldy #3 ldy #3
@ -819,7 +835,6 @@ goto:
tax ; save line # low tax ; save line # low
ora arg+3 ; fall through ? ora arg+3 ; fall through ?
bne goto1 bne goto1
; sta arg ; invalidate goto {#}
jmp execend jmp execend
usr: usr:
@ -840,10 +855,14 @@ prnum0:
jsr prnum jsr prnum
jmp execend jmp execend
goto_abort:
jsr test_abort ; check for ctrl-c or ctrl-z
goto1: goto1:
lda lparen ; set {!} as return line # lda acia_rx ; allow user abort
bne goto_abort
lda pound ; set {!} as return line #
sta bang sta bang
lda lparen+1 lda pound+1
sta bang+1 sta bang+1
inc bang ; + 1 inc bang ; + 1
bne goto11 bne goto11
@ -853,11 +872,11 @@ goto11:
ldy arg+3 ; is physical address pointer ? ldy arg+3 ; is physical address pointer ?
cpy #$ff cpy #$ff
beq goto3 beq goto3
ora lparen ; direct mode ? ora pound ; direct mode ?
beq goto12 beq goto12
cpy lparen+1 ; set carry flag for find cpy pound+1 ; set carry flag for find
bne goto2 bne goto2
cpx lparen cpx pound
bne goto2 bne goto2
ldy #4 ; same line - start over ldy #4 ; same line - start over
jmp exec jmp exec
@ -878,12 +897,7 @@ jstart3:
goto12: goto12:
clc ; from start of prog clc ; from start of prog
goto2: goto2:
; tya ; different line stx pound ; line # goto - store target
; pha ; invalidate {;}
; txa ; restore line # low
; jmp exec3 ; store new line in {#}
stx pound ; store target
sty pound+1 sty pound+1
jsr find jsr find
bcs jstart3 ; end of program bcs jstart3 ; end of program
@ -910,11 +924,9 @@ goto4:
goto7: goto7:
ldy #1 ; load line # ldy #1 ; load line #
lda (at),y lda (at),y
sta lparen
sta pound sta pound
iny iny
lda (at),y lda (at),y
sta lparen+1
sta pound+1 sta pound+1
ldy #4 ldy #4
jmp exec jmp exec
@ -970,57 +982,20 @@ prnum3:
; array element expression enclosed in {: )}, or a ; array element expression enclosed in {: )}, or a
; system variable (which may have side-effects) ; system variable (which may have side-effects)
; entry: @[y] -> expression text, x -> argument ; entry: @[y] -> expression text, x -> argument
; uses: getval:, oper:, {@}, argument stack area ; uses: getval:, {@}, argument stack area
; exit: arg[x] = result, @[y] -> next text ; exit: arg[x] = result, @[y] -> next text
; ;
eval: eval:
; lda #0
; sta 0,x ; start evaluation by simulating
; sta 1,x ; {0+expression}
; lda #'+'
jsr getval ; arg[x] = value of first term jsr getval ; arg[x] = value of first term
jmp eval_gb ; startup skipping simulation jmp eval_gb ; startup skipping simulation
notdn:
pha ; stack alleged operator
inx ; advance the argument stack
inx ; pointer
jsr getval ; arg[x+2] = value of next term
dex
dex
pla ; retrieve and apply the operator
jsr oper ; to arg[x], arg[x+2]
; jsr getbyte ; end of expression?
; beq evalrts ; (null or right parenthesis)
; iny
eval_gb: ; inline getbyte
lda (at),y
beq evalrts
cmp #';' ; statement delimiter ?
beq evalrts
iny ; skip over any space char(s)
cmp #' ' ; is space?
beq eval_gb ; end inline
cmp #')' ; no: skip over the operator
bne notdn ; and continue the evaluation
evalrts:
rts ; yes: return with final result
;-----------------------------------------------------; ;-----------------------------------------------------;
; Get numeric value of the term at @[y] into var[x] ; Get numeric value of the term at @[y] into var[x]
; Some examples of valid terms: 123, $, H, (15-:J)/?) ; Some examples of valid terms: 123, $, H, (15-:J)/?)
; ;
getval: getval:
; jsr cvbin ; decimal number at @[y]?
; lda #0
; sta 0,x ; var[x] = 0
; sta 1,x
lda (at),y ; get variable or constant lda (at),y ; get variable or constant
bpl getvar bpl getvar
; cmp ';'
; beq getrts
iny iny
; cmp #' ' ; skip space
; beq getval
; get constant ; get constant
cmp #$fd ; constant type ? cmp #$fd ; constant type ?
bcs getword bcs getword
@ -1075,10 +1050,6 @@ getv_byp:
cmp #$60 ; line # variable cmp #$60 ; line # variable
bcs gotomark 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 sty dolr ; get simple variable
asl a asl a
ora #$80 ora #$80
@ -1160,7 +1131,7 @@ in_val3:
; Set var[x] to the address of the variable named in a ; Set var[x] to the address of the variable named in a
; entry: a holds variable name, @[y] -> text holding ; entry: a holds variable name, @[y] -> text holding
; array index expression (if a = ':') ; array index expression (if a = ':')
; uses: plus, eval, oper8d, {@ &} ; uses: eval, {@ &}
; exit: (eq): var[x] -> variable, @[y] unchanged ; exit: (eq): var[x] -> variable, @[y] unchanged
; (ne): var[x] -> array element, ; (ne): var[x] -> array element,
; @[y] -> following text ; @[y] -> following text
@ -1172,11 +1143,14 @@ convp_array:
jsr eval ; yes: evaluate array index at jsr eval ; yes: evaluate array index at
asl 0,x ; @[y] and advance y asl 0,x ; @[y] and advance y
rol 1,x rol 1,x
clc
lda ampr ; var[x] -> array element lda ampr ; var[x] -> array element
sta 2,x ; at address 2*index+& adc 0,x ; at address 2*index+&
sta 0,x
lda ampr+1 lda ampr+1
sta 3,x adc 1,x
bne plus ; (always taken) sta 1,x
rts
; The following section is designed to translate the ; The following section is designed to translate the
; named simple variable from its ASCII value to its ; named simple variable from its ASCII value to its
; zero-page address. In this case, 'A' translates ; zero-page address. In this case, 'A' translates
@ -1197,7 +1171,7 @@ simple:
; exit: overflow is ignored/discarded, var[x+2] and ; exit: overflow is ignored/discarded, var[x+2] and
; {>} are modified, a = 0 ; {>} are modified, a = 0
; ;
mul: op_mul:
lda 0,x lda 0,x
sta gthan sta gthan
lda 1,x ; {>} = var[x] lda 1,x ; {>} = var[x]
@ -1212,7 +1186,6 @@ mul2:
lsr gthan+1 lsr gthan+1
ror gthan ; {>} /= 2 ror gthan ; {>} /= 2
bcc mul3 bcc mul3
; jsr plus ; form the product in var[x]
clc ; inline plus clc ; inline plus
lda 0,x lda 0,x
adc 2,x adc 2,x
@ -1227,44 +1200,51 @@ mul3:
ora 3,x ; loop until var[x+2] = 0 ora 3,x ; loop until var[x+2] = 0
bne mul2 bne mul2
mulrts: mulrts:
rts jmp eval_gb
;-----------------------------------------------------; ;-----------------------------------------------------;
; var[x] += var[x+2] ; var[x] += var[x+2]
; 14 bytes ;
plus: op_plus:
clc clc
lda 0,x lda 0,x
adc 2,x adc 2,x
sta 0,x sta 0,x
lda 1,x lda 1,x
adc 3,x adc 3,x
sta 1,x jmp op_ret
rts
;-----------------------------------------------------; ;-----------------------------------------------------;
; expects: - ; expects: -
; ;
then_: op_else:
lda 0,x
ora 1,x
beq then_exit
else_true:
lda 2,x
sta 0,x
lda 3,x
sta 1,x
then_exit:
rts
;-----------------------------------------------------;
; expects: -
;
else_:
lda 0,x lda 0,x
ora 1,x ora 1,x
beq else_true beq else_true
lda #0 lda #0
sta 0,x sta 0,x
sta 1,x jmp op_ret
rts ;-----------------------------------------------------;
; var[x] -= var[x+2]
; expects: (cs)
;
op_minus:
lda 0,x
sbc 2,x
sta 0,x
lda 1,x
sbc 3,x
jmp op_ret
;-----------------------------------------------------;
; expects: -
;
op_then:
lda 0,x
ora 1,x
beq eval_gb
else_true:
lda 2,x
sta 0,x
lda 3,x
jmp op_ret
;-----------------------------------------------------; ;-----------------------------------------------------;
; Apply the binary operator in a to var[x] and var[x+2] ; Apply the binary operator in a to var[x] and var[x+2]
; Valid VTL02C operators are {* + / [ ] - | ^ & < = >} ; Valid VTL02C operators are {* + / [ ] - | ^ & < = >}
@ -1272,25 +1252,51 @@ else_:
; An undefined operator will be interpreted as one of ; An undefined operator will be interpreted as one of
; the three comparison operators ; the three comparison operators
; ;
notdn:
pha ; stack alleged operator
inx ; advance the argument stack
inx ; pointer
jsr getval ; arg[x+2] = value of next term
dex
dex
pla ; retrieve and apply the operator
oper: oper:
cmp #'+' ; addition operator?
beq plus
cmp #'*' ; multiplication operator?
beq mul
cmp #'/' ; division operator? cmp #'/' ; division operator?
beq div bcs op_byp1
cmp #'[' ; "then" operator? cmp #'+' ; addition operator?
beq then_ beq op_plus
cmp #']' ; "else" operator? cmp #'*' ; multiplication operator?
beq else_ beq op_mul
cmp #'-' ; subtraction operator? cmp #'-' ; subtraction operator?
beq minus beq op_minus
cmp #OP_OR ; bit-wise or operator?
beq or_
cmp #'^' ; bit-wise xor operator?
beq xor_
cmp #'&' ; bit-wise and operator? cmp #'&' ; bit-wise and operator?
beq and_ beq op_and
if OP_OR < '/'
cmp #OP_OR ; bit-wise or operator?
beq op_or
endif
op_byp1:
beq op_div
cmp #'[' ; "then" operator?
bcc op_byp2
beq op_then
cmp #']' ; "else" operator?
beq op_else
if OP_OR > '/'
cmp #OP_OR ; bit-wise or operator?
beq op_or
endif
cmp #'^' ; bit-wise xor operator?
beq op_xor
cmp #'}' ; shift right operator?
bne skp_shr
jmp op_shr
skp_shr:
cmp #'{' ; shift left operator
bne skp_shl
jmp op_shl
skp_shl:
op_byp2:
; - - - - - - - - - - - - - - - - - - - - - - - - - - ; ; - - - - - - - - - - - - - - - - - - - - - - - - - - ;
; Apply comparison operator in a to var[x] and var[x+2] ; Apply comparison operator in a to var[x] and var[x+2]
; and place result in var[x] (1: true, 0: false) ; and place result in var[x] (1: true, 0: false)
@ -1298,7 +1304,6 @@ oper:
; ;
eor #'<' ; 0: '<' 1: '=' 2: '>' eor #'<' ; 0: '<' 1: '=' 2: '>'
sta gthan ; other values in a are undefined, sta gthan ; other values in a are undefined,
; jsr minus ; but _will_ produce some result
lda 0,x ; inline minus lda 0,x ; inline minus
sbc 2,x sbc 2,x
sta 0,x sta 0,x
@ -1318,62 +1323,60 @@ oper8c:
and #1 ; var[x] = 1 (true), 0 (false) and #1 ; var[x] = 1 (true), 0 (false)
sta 0,x sta 0,x
lda #0 lda #0
sta 1,x op_ret
rts sta 1,x ; store result high
;-----------------------------------------------------; eval_gb:
; var[x] -= var[x+2] lda (at),y ; get next operator
; expects: (cs) beq evalrts
; 13 bytes cmp #';' ; statement delimiter ?
minus: beq evalrts
lda 0,x iny ; skip over any space char(s)
sbc 2,x cmp #' ' ; is space?
sta 0,x beq eval_gb ; end inline
lda 1,x
sbc 3,x cmp #')' ; no: skip over the operator
sta 1,x bne notdn ; and continue the evaluation
rts evalrts:
rts ; yes: return with final result
;-----------------------------------------------------; ;-----------------------------------------------------;
; var[x] &= var[x+2] ; var[x] &= var[x+2]
; expects: - ; expects: -
; 13 bytes ;
and_: op_and:
lda 0,x lda 0,x
and 2,x and 2,x
sta 0,x sta 0,x
lda 1,x lda 1,x
and 3,x and 3,x
sta 1,x jmp op_ret
rts
;-----------------------------------------------------; ;-----------------------------------------------------;
; var[x] |= var[x+2] ; var[x] |= var[x+2]
; expects: - ; expects: -
; 13 bytes ;
or_: op_or:
lda 0,x lda 0,x
ora 2,x ora 2,x
sta 0,x sta 0,x
lda 1,x lda 1,x
ora 3,x ora 3,x
sta 1,x jmp op_ret
rts
;-----------------------------------------------------; ;-----------------------------------------------------;
; var[x] ^= var[x+2] ; var[x] ^= var[x+2]
; expects: - ; expects: -
; 13 bytes ;
xor_: op_xor:
lda 0,x lda 0,x
eor 2,x eor 2,x
sta 0,x sta 0,x
lda 1,x lda 1,x
eor 3,x eor 3,x
sta 1,x jmp op_ret
rts
;-----------------------------------------------------; ;-----------------------------------------------------;
; 16-bit unsigned division routine ; 16-bit unsigned division routine
; var[x] /= var[x+2], {%} = remainder, {>} modified ; var[x] /= var[x+2], {%} = remainder, {>} modified
; var[x] /= 0 produces {%} = var[x], var[x] = 65535 ; var[x] /= 0 produces {%} = var[x], var[x] = 65535
; 43 bytes ;
div: op_div:
lda #0 lda #0
sta remn ; {%} = 0 sta remn ; {%} = 0
sta remn+1 sta remn+1
@ -1397,7 +1400,26 @@ div1:
div2: div2:
dec gthan dec gthan
bne div1 ; loop 16 times bne div1 ; loop 16 times
rts sop_ret
jmp eval_gb
;-----------------------------------------------------;
; var[x] shifted right by var[x+2] places
;
op_shr:
dec 2,x
bmi sop_ret
lsr 1,x
ror 0,x
jmp op_shr
;-----------------------------------------------------;
; var[x] shifted left by var[x+2] places
;
op_shl:
dec 2,x
bmi sop_ret
asl 0,x
rol 1,x
jmp op_shl
;-----------------------------------------------------; ;-----------------------------------------------------;
; If text at @[y] is a decimal constant, translate it ; If text at @[y] is a decimal constant, translate it
; into var[x] (discarding any overflow) and update y ; into var[x] (discarding any overflow) and update y
@ -1405,8 +1427,8 @@ div2:
; leading space characters are skipped, but ; leading space characters are skipped, but
; any spaces encountered after a conversion ; any spaces encountered after a conversion
; has begun will end the conversion. ; has begun will end the conversion.
; used by: user:, getval: ; used by: user:, d2b:
; uses: mul:, plus:, var[x], var[x+2], {@ > ?} ; uses: var[x], var[x+2], {@ > ?}
; exit: (ne): var[x] = constant, @[y] -> next text ; exit: (ne): var[x] = constant, @[y] -> next text
; (eq): var[x] = 0, @[y] unchanged ; (eq): var[x] = 0, @[y] unchanged
; (cs): in all but the truly strangest cases ; (cs): in all but the truly strangest cases
@ -1415,9 +1437,6 @@ cvbin:
lda #0 lda #0
sta 0,x ; var[x] = 0 sta 0,x ; var[x] = 0
sta 1,x sta 1,x
; sta 3,x
; jsr getbyte ; skip any leading spaces
; sty ques ; save pointer
cvb_gb1: ; inline getbyte cvb_gb1: ; inline getbyte
sty ques ; save pointer sty ques ; save pointer
lda (at),y lda (at),y
@ -1435,10 +1454,6 @@ cvbin2:
cmp #10 ; decimal digit then stop cmp #10 ; decimal digit then stop
bcs cvbin3 ; the conversion bcs cvbin3 ; the conversion
pha ; save decimal digit pha ; save decimal digit
; lda #10
; sta 2,x
; jsr mul ; var[x] *= 10
; sta 3,x
lda 1,x ; inline multiply by 10 lda 1,x ; inline multiply by 10
sta gthan+1 sta gthan+1
lda 0,x lda 0,x
@ -1456,8 +1471,6 @@ cvbin2:
rol a rol a
sta 1,x ; end inline sta 1,x ; end inline
pla ; retrieve decimal digit pla ; retrieve decimal digit
; sta 2,x
; jsr plus ; var[x] += digit
clc ; inline add digit clc ; inline add digit
adc 0,x adc 0,x
sta 0,x sta 0,x
@ -1479,8 +1492,6 @@ cvbin3:
; uses: inch:, outnl:, linbuf, {@} ; uses: inch:, outnl:, linbuf, {@}
; exit: @[y] -> linbuf ; exit: @[y] -> linbuf
; ;
;newln:
; jsr outnl ; yes: discard entire line
inln: inln:
ldy #lo(linbuf); entry point: start a fresh line ldy #lo(linbuf); entry point: start a fresh line
sty at ; {@} -> input line buffer sty at ; {@} -> input line buffer
@ -1533,7 +1544,7 @@ inlnesc1:
; exit: (cs): {@}, x:a and {(} undefined, y = 3 ; exit: (cs): {@}, x:a and {(} undefined, y = 3
; (cc): {@} -> beginning of found line, y = 3, ; (cc): {@} -> beginning of found line, y = 3,
; x:a = {(} = actual found line number ; x:a = {(} = actual found line number
; 62 bytes ;
find: find:
ldx #hi(prgm) ldx #hi(prgm)
lda #lo(prgm) lda #lo(prgm)
@ -1674,18 +1685,6 @@ d2bex:
rts rts
jd2blp: jd2blp:
jmp d2blp jmp d2blp
;-----------------------------------------------------;
; Fetch a byte at @[y], ignoring space characters
; 10 bytes
;skpbyte:
; iny ; skip over current char
;getbyte:
; lda (at),y
; beq getbyt2
; cmp #' '
; beq skpbyte ; skip over any space char(s)
;getbyt2:
; rts
;============ Original I/O subroutines ===============; ;============ Original I/O subroutines ===============;
;-----------------------------------------------------; ;-----------------------------------------------------;
; Check for user keypress and return with (cc) if none ; Check for user keypress and return with (cc) if none
@ -1730,15 +1729,11 @@ timr_adr = timr_var*2|$80
inkey: inkey:
lda acia_rx ; Is there a character waiting? lda acia_rx ; Is there a character waiting?
beq inkeyr ; no: return beq inkeyr ; no: return
; cmp #3 ; is ctrl-c
; beq istart ; yes: abort to OK prompt
jsr test_abort jsr test_abort
inkeyp: inkeyp:
lda acia_rx ; pause until next key lda acia_rx ; pause until next key
beq inkeyp beq inkeyp
jsr test_abort jsr test_abort
; cmp #3 ; is ctrl-c
; beq istart ; yes: abort to OK prompt
inkeyr: inkeyr:
rts rts
; - - - - - - - - - - - - - - - - - - - - - - - - - - ; ; - - - - - - - - - - - - - - - - - - - - - - - - - - ;
@ -1769,13 +1764,10 @@ skip_esc_discard:
cpy #1 cpy #1
bne inch ; discard escape sequence bne inch ; discard escape sequence
lda #27 ; escape only - send to vtl lda #27 ; escape only - send to vtl
; ldy dolr
; rts
skip_esc_no skip_esc_no
ldy dolr ; restore y reg ldy dolr ; restore y reg
inch2: inch2:
and #$7f ; ensure char is positive ascii and #$7f ; ensure char is positive ascii
; cmp #$03 ; ctrl-C?
jsr test_abort jsr test_abort
cmp #BS ; only echo printable, bs & cr cmp #BS ; only echo printable, bs & cr
beq outch beq outch