;
; Program: GOTO
; Author: Richard Conn
; Version: 1.0
; Date: 8 Mar 84
; Previous Versions: None
;
version equ 10
;
; GOTO is a program designed to be run under ZEX which permits
; branching within a ZEX file. It accepts only one argument, a label,
; which is defined within the ZEX file as a special comment of the
; form:
; ;=label anytext
; The syntax of GOTO is:
; GOTO label
;
;
; Basic Equates
;
z3env SET 0f400h ;Environment Descriptor
fcb equ 5ch
cr equ 0dh
lf equ 0ah
lflag equ '=' ;label flag in comment
;
; Environment Definition
;
if z3env ne 0
;
; External ZCPR3 Environment Descriptor
;
jmp start
db 'Z3ENV' ;This is a ZCPR3 Utility
db 1 ;External Environment Descriptor
z3eadr:
dw z3env
start:
lhld z3eadr ;pt to ZCPR3 environment
;
else
;
; Internal ZCPR3 Environment Descriptor
;
MACLIB Z3BASE.LIB
MACLIB SYSENV.LIB
z3eadr:
jmp start
SYSENV
start:
lxi h,z3eadr ;pt to ZCPR3 environment
endif
;
; Start of Program -- Initialize ZCPR3 Environment
;
call z3init ;initialize the ZCPR3 Env and the VLIB Env
;
; Check for Valid Label
;
lda fcb+1 ;get first char of FCB
cpi ' ' ;no label?
jz help
cpi '/'
jnz start1
;
; Print GOTO Help
;
help:
call print
db 'GOTO, Version '
db (version/10)+'0','.',(version mod 10)+'0'
db cr,lf,'GOTO -- Branch Within a ZEX File'
db cr,lf,'Syntax:'
db cr,lf,' GOTO label'
db cr,lf,'where "label" is defined by a special comment of'
db cr,lf,'the form ";',lflag,'label".',0
ret
;
; Check for Running ZEX
;
start1:
call getzrun ;get ZEX run flag
jnz start2
call print
db ' ZEX Not Running',0
ret
;
; Begin Scan of ZEX Message Buffer
;
start2:
call getzfc ;get ptr to first ZEX char
lxi d,fcb+1 ;pt to GOTO label
;
; Scan for Label Comment
;
scanc:
mov a,m ;get char
cpi ';' ;comment?
jnz flush ;advance to next line
dcx h ;pt to next
mov a,m
cpi lflag ;label?
jnz flush ;advance to next line if not label
;
; We have a label - check it
;
push h ;save ptrs
push d
dcx h ;pt to first char
mvi b,8 ;at most 8 chars
label:
ldax d ;get GOTO char
cpi ' ' ;done?
jz label1
mov c,a
mov a,m
call caps ;capitalize label in ZEX file
cmp c ;compare
jnz label2
dcx h ;advance
inx d
dcr b
jnz label
;
; Label Matches
;
label1:
mov a,m ;must be space or less for match
cpi ' '+1
jnc label2
pop d ;restore ptrs
pop h
;
; Advance to Beginning of Next Line
;
nxtline:
mov a,m ;get char
dcx h ;pt to next
cpi cr ;end of line?
jz nxtl1
cpi 0ffh ;end of processing?
jnz nxtline
nxtl1:
call putznc ;store ptr to next char
call print
db ' GOTO Label ',0
jmp prlabel
;
; No Match on Label
;
label2:
pop d ;restore regs
pop h
;
; Flush to Next Line or EOB
;
flush:
mov a,m ;get next char
cpi 0ffh ;end of buffer?
jz notfnd
dcx h ;pt to next
cpi cr ;end of line?
jnz flush
jmp scanc ;resume search
;
; Label Not Found
;
notfnd:
call print
db ' Label ',0
call prlabel ;print label
call print
db ' Not Found -- Aborting ZEX',0
xra a ;turn off ZEX
jmp putzrun
;
; Print Label Name
;
prlabel:
mvi b,8
lxi h,fcb+1
prl1:
mov a,m ;get next char
cpi ' ' ;done?
rz
call cout ;print char
inx h
dcr b ;count down
jnz prl1
ret
