Tektronix 2714, Programmer'S Manual

Page: 215 / 308

Programming
2714 & 2715 Programmer Manual
6–17
COLOR frgrnd%, bckgrnd%
LOCATE p% + 18, q% + 20
PRINT before$(p%, q%);
NEXT q%
NEXT p%
IF min% > hold.min% THEN
min% = min% + 1
hold.min% = min%
ELSE
min% = min% + 1
hold.min% = 0
END IF
NEXT index%
'
LOCATE hold.y%, hold.x%
COLOR 14, 9
rd$ = ""
'
RETURN
'
READ.FOR.VERBOSE:
'
end.of.read$ = "N"
error.query$ = "N" 'two flags used in reading
' response from 2714 or 2715
COM(1) ON 'enable event trapping for
' communication activity on
' com port 1
i = TIMER
DO WHILE end.of.read$ = "N" 'Give 60 seconds for response
' from event query.
I F TI MER > i + 60 THEN 'If no response, assume
' communication
COM(1) OFF 'not established, so set
' flag to indicate
end.of.read$ = "Y" 'this.
error.query$ = "Y"
END IF
LOOP
'
'======================================================
' begin checking for error flags after return from read
'======================================================
'
IF error.query$ = "Y" THEN 'no communication
' established
GOSUB ERROR.DISPLAY 'display error