Measurement Computing Personal488 rev.3.0 For DOS & Windows 3.Xi - Manual (Page 119)

8K. Other Languages II. SOFTWARE GUIDES - 8. Driver488/DRV
II-104 Personal488 User’s Manual, Rev. 3.0
brk DB “BREAK” ;BREAK command text
brklen EQU $-brk ;Length of break command
mov AX, 4403h ;IOCTL Write function
mov BX, ieee ;File handle
mov CX, brklen ;# chars to send
mov DX, offset brk ;DS:DX -> command
int 21h ;Execute DOS function
jc error ;Check for error
mov AX, 4402h ;IOCTL Read function
mov BX, ieee ;File handle
mov CX, ioctllen ;# chars to read
mov DX, offset
ioctlbuf ;DS:DX - buffer
int 21h ;Execute DOS function
jc error ;Check for error
mov AH, 40h ;DOS Write function
mov BX, ieee ;File handle
mov CX, hellolen ;Command length
mov DX, offset hello ;DS:DX - command
int 21h ;Execute DOS function
jc error ;Check for error
mov AH, 3Fh ;DOS Read function
mov BX, ieee ;File handle
mov CX, responselen ;Buffer length
mov DX, offset
response ;DS:DX - buffer
int 21h ;Execute DOS function
jc error ;Check for error
mov recvdlen, AX ;Save # of characters received
mov AX, 0400h ;Test light pen function
int 10h ;Video BIOS interrupt
or AH, AH ;Check AH
jnz GotInt ;Non-zero means interrupt detected
mov AX, 0400h ;Repeat the test
int 10h
or AH, AH
jnz GotInt