I compiled the source code ( InpOut32 ) provided on this web site, when I run it, I found I can only write / read Data register(0x378), the control register's(0x37A) value seems always be 63 on windows 7 64bit (on both of 2 different machines). When I switched to windows 7 32bit on one of these 2 machines(I will test the other machine next monday), I can change the low 6 bits of Control register, and the highest 2 bits are always 11.
Any clues are welcomed, thanks in advance.
Jeff
Cannot write into Control register on windows 7 64bit platform
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zhimakaimen
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Re: Cannot write into Control register on windows 7 64bit platform
Have you gone into the BIO/UEFI to change the parallel port mode?zhimakaimen wrote: Sat Mar 02, 2019 11:19 am I compiled the source code ( InpOut32 ) provided on this web site, when I run it, I found I can only write / read Data register(0x378), the control register's(0x37A) value seems always be 63 on windows 7 64bit (on both of 2 different machines). When I switched to windows 7 32bit on one of these 2 machines(I will test the other machine next monday), I can change the low 6 bits of Control register, and the highest 2 bits are always 11.
Any clues are welcomed, thanks in advance.
Jeff
Some modes are very complex, I typically use "Output Only" or SPP (every bios names them differently though)
Re: Cannot write into Control register on windows 7 64bit platform
I’ve run into similar issues when working with I/O ports on Windows, especially with the 64-bit version. It’s frustrating when the control register doesn’t change like it should. In my experience, permissions can really mess with how the registers behave, so running your app as an administrator might help. I remember having to tweak some driver settings too when I was trying to get my setup to work properly.