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GeneralProblem in FILETIME Pin
SSD_9-Aug-04 21:36
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GeneralRe: Problem in FILETIME Pin
David Crow10-Aug-04 3:34
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GeneralHeap Allocation in Member Initialization List Pin
Johann Gerell9-Aug-04 21:20
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GeneralError in CBT_HOOK function Pin
fu09-Aug-04 20:42
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GeneralRe: Error in CBT_HOOK function Pin
Mike Beckerleg10-Aug-04 5:38
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QuestionHow to know the current logon user is Administrator or Limited user? Pin
ErisonWu9-Aug-04 20:29
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AnswerRe: How to know the current logon user is Administrator or Limited user? Pin
Amarelia9-Aug-04 22:57
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GeneralRe: How to know the current logon user is Administrator or Limited user? Pin
ErisonWu10-Aug-04 23:10
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AnswerRe: How to know the current logon user is Administrator or Limited user? Pin
Juha Silmujarvi10-Aug-04 1:27
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GeneralRe: How to know the current logon user is Administrator or Limited user? Pin
ErisonWu10-Aug-04 23:03
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Generalfind the current logged on user Pin
Anonymous9-Aug-04 20:13
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GeneralRe: find the current logged on user Pin
parths9-Aug-04 20:26
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Questionwhat is usual gamma correction value for generic printer? Pin
baboguru9-Aug-04 19:48
baboguru9-Aug-04 19:48 
GeneralParallel Port Question Pin
zahid_ash9-Aug-04 19:44
zahid_ash9-Aug-04 19:44 
GeneralRe: Parallel Port Question Pin
Antti Keskinen9-Aug-04 21:22
Antti Keskinen9-Aug-04 21:22 
GeneralRe: Parallel Port Question Pin
zahid_ash9-Aug-04 21:33
zahid_ash9-Aug-04 21:33 
GeneralRe: Parallel Port Question Pin
Antti Keskinen10-Aug-04 0:08
Antti Keskinen10-Aug-04 0:08 
GeneralRe: Parallel Port Question Pin
zahid_ash10-Aug-04 0:38
zahid_ash10-Aug-04 0:38 
GeneralRe: Parallel Port Question Pin
Antti Keskinen10-Aug-04 1:23
Antti Keskinen10-Aug-04 1:23 
GeneralRe: Parallel Port Question Pin
zahid_ash10-Aug-04 1:59
zahid_ash10-Aug-04 1:59 
GeneralRe: Parallel Port Question Pin
Antti Keskinen10-Aug-04 2:41
Antti Keskinen10-Aug-04 2:41 
This happens because both your application and the device are writing to the port at the same time.

The Inpout32 library, when you call Out32(), will set the port's pins to represent the value you specify. This means that the pins will stay powered even after the call is completed.

To initiate succesfull communication with your device through the same port, first use Out32(888, 0) to clear any previous outputs. Then write Out32(888, 18). Now make your device read the value in some way (press a button, for example). When done, write Out32(888, 0) again. Put your device to send data, and use Inp32 to read the value.

The problem itself is simple: both you and the device are issuing voltage to the port's pins. This means that if you write 00000001 and your device answers to this by putting 10000000, the port will end up with 10000001, unless you clear your own output first. So, the trick is to call Out32(888, 0) before reading the input.

-Antti Keskinen

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GeneralRe: Parallel Port Question Pin
zahid_ash10-Aug-04 2:15
zahid_ash10-Aug-04 2:15 
GeneralRe: Parallel Port Question Pin
kandyelectrical12-Dec-12 22:50
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QuestionHow to know security context ? Pin
Amarelia9-Aug-04 19:16
Amarelia9-Aug-04 19:16 
GeneralcreateEventObject fails Pin
yourbuddy779-Aug-04 19:05
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