þa‹Rþdþwÿÿÿÿÿÿÿÿÿÿþ mx9þhý oPþ nSystem-wide NAME GPIBIfce DGROUP GROUP DATA CGROUP GROUP CODE STACK SEGMENT STACK 'STACK' STACK ENDS ASSUME CS:CGROUP, DS:DGROUP, SS:STACK ; --------------------------------------------------------------------------- ; Code Size Data Size ; --------- --------- ; small large ; --------------------------------------------------------------------------- ; data structure for accessing parameters on the stack nparams struc ; for a near procedure nold_bp dw ? nreturn dw ? nptr_1 dd ? nptr_2 dd ? nparams ends ; data structure for accessing parameters on the stack rwparams struc ; for a near procedure rwold_bp dw ? rwreturn dw ? rwperror dd ? rwlength dw ? rwpbuffer dd ? rwhandle dw ? rwparams ends DATA SEGMENT PUBLIC 'DATA' DATA ENDS CODE SEGMENT PUBLIC 'CODE' PUBLIC itopenraw, itclose PUBLIC itreadioctl, itwriteioctl, itread, itwrite ;------------------------------------------------------------------------- itopenraw PROC NEAR ; WORD handle = itopenraw (pname, perror) PUSH BP MOV BP, SP SUB SP, 2 ; make space for file handle PUSH DS ; save original DS LDS DX, [BP].nptr_2 ; load pointer to name string MOV AX, 3D01H ; DOS open file for write ; MOV AX, 3D02H ; DOS open file for read/write INT 21H POP DS ; restore original DS JC itopenrawexit ; branch if error MOV WORD PTR[BP - 2], AX ; save file handle MOV BX, AX ; put file handle in BX MOV AX, 4400H ; DOS Ioctl get device info INT 21H JC errinioctl ; branch if error MOV BX, WORD PTR[BP - 2] ; load file handle MOV DH, 0 ; force DH = 0 OR DL, 20H ; set raw mode bit MOV AX, 4401H ; DOS Ioctl set device info INT 21H JC errinioctl ; branch if error XOR AX, AX ; done ok, so set error to zero JMP itopenrawexit errinioctl: ; error returned in ioctl PUSH AX ; save error temporarily MOV BX, WORD PTR[BP - 2] ; load file handle MOV AH, 3EH ; DOS close file INT 21H MOV WORD PTR[BP - 2], 0FFFFh ; put 'bad' value in handle POP AX ; put saved error back in AX itopenrawexit: ; done, error is in AX LES BX, [BP].nptr_1 ; load pointer to error word MOV ES:[BX], AX ; return error MOV AX, WORD PTR[BP - 2] ; load file handle to return MOV SP, BP ; remove local variable POP BP ; restore original base pointer RET 8 ; pop address of arguments itopenraw ENDP ;------------------------------------------------------------------------- itclose PROC NEAR ; itclose (handle, perror) PUSH BP MOV BP, SP MOV BX, [BP].rwlength ; load file handle MOV AH, 3EH ; DOS close file INT 21H JC itcloseexit ; branch if error XOR AX, AX ; done ok, so set error to zero itcloseexit: ; done, error is in AX LES BX, [BP].rwperror ; load pointer to error word MOV ES:[BX], AX ; return error POP BP ; restore original base pointer RET 6 ; pop address of arguments itclose ENDP ;------------------------------------------------------------------------- itreadioctl PROC NEAR ; WORD lengthread = itreadioctl (handle, pbuffer, length, pError) PUSH BP MOV BP, SP PUSH DS ; restore original DS MOV BX, [BP].rwhandle ; load file handle LDS DX, [BP].rwpbuffer ; load buffer pointer MOV CX, [BP].rwlength ; load length to read MOV AX, 4402H ; DOS IOCTL read INT 21H POP DS ; restore original DS XOR CX, CX ; either length or error will be zero JC itreadioctlexit ; branch if error XCHG AX, CX ; done ok, so error gets the zero itreadioctlexit: ; done, error is in AX, length is in CX LES BX, [BP].rwperror ; load pointer to error word MOV ES:[BX], AX ; return error MOV AX, CX ; return length POP BP ; restore original base pointer RET 12 ; pop address of arguments itreadioctl ENDP ;------------------------------------------------------------------------- itwriteioctl PROC NEAR ; WORD lengthwritten = itwriteioctl (handle, pbuffer, length, pError) PUSH BP MOV BP, SP PUSH DS ; restore original DS MOV BX, [BP].rwhandle ; load file handle LDS DX, [BP].rwpbuffer ; load buffer pointer MOV CX, [BP].rwlength ; load length to read MOV AX, 4403H ; DOS IOCTL read INT 21H POP DS ; restore original DS XOR CX, CX ; either length or error will be zero JC itwriteioctlexit ; branch if error XCHG AX, CX ; done ok, so error gets the zero itwriteioctlexit: ; done, error is in AX, length is in CX LES BX, [BP].rwperror ; load pointer to error word MOV ES:[BX], AX ; return error MOV AX, CX ; return length POP BP ; restore original base pointer RET 12 ; pop address of arguments itwriteioctl ENDP ;------------------------------------------------------------------------- itread PROC NEAR ; WORD lengthread = itread (handle, pbuffer, length, pError) PUSH BP MOV BP, SP PUSH DS ; restore original DS MOV BX, [BP].rwhandle ; load file handle LDS DX, [BP].rwpbuffer ; load buffer pointer MOV CX, [BP].rwlength ; load length to read MOV AH, 3FH ; DOS read INT 21H POP DS ; restore original DS XOR CX, CX ; either length or error will be zero JC itreadexit ; branch if error XCHG AX, CX ; done ok, so error gets the zero itreadexit: ; done, error is in AX, length is in CX LES BX, [BP].rwperror ; load pointer to error word MOV ES:[BX], AX ; return error MOV AX, CX ; return length POP BP ; restore original base pointer RET 12 ; pop address of arguments itread ENDP ;------------------------------------------------------------------------- itwrite PROC NEAR ; WORD lengthwritten = itwrite (handle, pbuffer, length, pError) PUSH BP MOV BP, SP PUSH DS ; restore original DS MOV BX, [BP].rwhandle ; load file handle LDS DX, [BP].rwpbuffer ; load buffer pointer MOV CX, [BP].rwlength ; load length to read MOV AH, 40H ; DOS read INT 21H POP DS ; restore original DS XOR CX, CX ; either length or error will be zero JC itwriteexit ; branch if error XCHG AX, CX ; done ok, so error gets the zero itwriteexit: ; done, error is in AX, length is in CX LES BX, [BP].rwperror ; load pointer to error word MOV ES:[BX], AX ; return error MOV AX, CX ; return length POP BP ; restore original base pointer RET 12 ; pop address of arguments itwrite ENDP ;------------------------------------------------------------------------- CODE ENDS END