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BASIC programs with access to the program loader (LOAD) by passing parameters via the system parameter area (SYSPARM)


This program provides BASIC programs with access to the program loader (LOAD)
by passing parameters via the system parameter area (SYSPARM).

;BASLOAD.ASM
;----------------------------------------------------------------------------
;
;Inputs:
;  FILE SPEC 1 - A string (len <= 80) with the complete name, including
;  path, of the file to be loaded and executed.
;  Example: 'MAINMENU.EXE' or 'C:\FORMAT.COM'
;  PARAMETER 1  - A string (len <= 80) with the command line parameters
;  to be passed to the program specified in FILE SPEC 1.
;  Example: '' or 'A:'
;  FILE SPEC 2  - Same as 1.
;  PARAMETER 2  - Same as 1.
;
;Outputs:
;  This program gives control to LOAD.
;----------------------------------------------------------------------------




CODE SEGMENT 'CODE'
ASSUME CS:CODE


PUBLIC BASLOAD ;make known to BASIC at link time
BASLOAD PROC FAR

;prologue
PUSH BP ;save BP
MOV BP,SP ;set base for parm list
PUSH DS ;DS -> basic work area
PUSH ES ;ES -> basic work area
MOV DX,'dk' ;interrupt verification switch
INT 77H ;get seg address of sysparm area in AX
MOV ES,AX ;ES -> sysparm area
CLD ;set direction for all moves

;move file spec 1 to sysparm
MOV BX,SS:[BP+12] ;get addr of string descriptor
MOV CX,DS:[BX] ;get length of string into CX
MOV SI,DS:[BX+2] ;get addr of string into SI
MOV DI,0 ;offset into sysparm
REP MOVSB ;move string
MOV BYTE PTR ES:[DI],0 ;make it asciiz string

;move parameter 1 to sysparm
MOV BX,SS:[BP+10] ;get addr of string descriptor
MOV CX,DS:[BX] ;get length of string into CX
MOV SI,DS:[BX+2] ;get addr of string into SI
MOV DI,81 ;offset into sysparm
INC CL ;adjust for cr to be added at end
MOV BYTE PTR ES:[DI],CL ;1st byte is length of string
DEC CL ;re-adjust for move operation
INC DI
REP MOVSB ;move string
MOV BYTE PTR ES:[DI],13 ;add cr to end

;move file spec 2 to sysparm
MOV BX,SS:[BP+8] ;get addr of string descriptor
MOV CX,DS:[BX] ;get length of string into CX
MOV SI,DS:[BX+2] ;get addr of string into SI
MOV DI,163 ;offset into sysparm
REP MOVSB ;move string
MOV BYTE PTR ES:[DI],0 ;make it asciiz string

;move parameter 2 to sysparm
MOV BX,SS:[BP+6] ;get addr of string descriptor
MOV CX,DS:[BX] ;get length of string into CX
MOV SI,DS:[BX+2] ;get addr of string into SI
MOV DI,244 ;offset into sysparm
INC CL ;adjust for cr to be added at end
MOV BYTE PTR ES:[DI],CL ;1st byte is length of string
DEC CL ;re-adjust for move operation
INC DI
REP MOVSB ;move string
MOV BYTE PTR ES:[DI],13 ;add cr to end

;exit to BASIC
POP ES
POP DS
POP BP
RET 8

BASLOAD ENDP

CODE ENDS
END BASLOAD

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