' Program to log data from printer port
' makes D0 go high (for pullup, pin 2)
' reads data from busy line (pin 11)
' note - slower machines might not keep up
' This version for picbot - 20x faster datarate
' Must run in dos, not multitasking!
CLS
PRINT "Logging data from LPT2..."
size = 5000
DIM datalog$(size)
dn = 0

'these machine dependent...
tc = 15     ' do nothing for-next
okL = 20    ' minimum count
okH = 30    ' maximum count
'uncomment PRINT count line and pick values that
'surround it close enough to ignore extra data

'outport = &H378   'LPT 1
 outport = &H278   'LPT 2

inport = outport + 1
OUT outport, 1

logloop:
d = INP(inport)
IF d > 127 THEN PRINT "waiting...";
IF d > 127 THEN GOTO logloop

waitloop:
d = INP(inport)
IF INKEY$ <> "" THEN GOTO quit
IF d < 128 THEN GOTO waitloop
count = 0

timeloop:
FOR td = 1 TO tc: NEXT td
d = INP(inport)
IF d < 128 THEN GOTO startbits
count = count + 1
GOTO timeloop

startbits:
 PRINT count    ' use to get values for okL and okH
IF count < okL OR count > okH THEN GOTO endloop
c2 = count / 2
z = 0
FOR t = 1 TO c2
IF z < 0 THEN REM
z = z + 1
FOR td = 1 TO tc: NEXT td
NEXT t
FOR bit = 0 TO 7
FOR t = 1 TO count
IF z < 0 THEN REM
z = z + 1
FOR td = 1 TO tc: NEXT td
NEXT t
d = INP(inport)
IF d < 128 THEN dat(bit) = 0 ELSE dat(bit) = 1
NEXT bit
' make sure next bit is 1
se = 0
FOR t = 1 TO count
IF z < 0 THEN REM
z = z + 1
FOR td = 1 TO tc: NEXT td
NEXT t
d = INP(inport)
IF d < 128 THEN PRINT "Error 1!": se = 1
' and next bit is 0
FOR t = 1 TO count
IF z < 0 THEN REM
z = z + 1
FOR td = 1 TO tc: NEXT td
NEXT t
d = INP(inport)
IF d > 127 THEN PRINT "Error 0!": se = 1

byte$ = ""
FOR bit = 7 TO 0 STEP -1
IF dat(bit) = 1 THEN d$ = "1" ELSE d$ = "0"
byte$ = byte$ + d$
NEXT bit
PRINT byte$
IF se = 0 THEN
  dn = dn + 1
  IF dn > size THEN GOTO quit
  datalog$(dn) = byte$
END IF

endloop:
IF INKEY$ = "" THEN GOTO logloop

quit:
OPEN "logfile.out" FOR OUTPUT AS #1
FOR i = 1 TO dn
PRINT #1, datalog$(i)
NEXT i
CLOSE #1

SYSTEM