about // port interfacing

[halt]

hi everybody i have just a lil question about parallel port interfacing
how can i do to control only one desired data bit in parallel port
so with outb/inb (0x378,n); (in c language) we can control all outputs or inputs
together but what i want to do is for example set the 3rd bit like in input and a 5th
as in output so every bit can be controlled separatly.

in reality i wanna create my own eeprom programmer . thx

 

[FoxyRick]

Hi,

As far as I am aware, you can't do this, at least in standard mode. There are quite a few simple parallel port EPROM programmers on the internet and none of them do this.

Have you read these two documents?





Some more good stuff:

https://www.epanorama.net/circuits/parallel_output.html


Cheers,
FoxyRick.

 

[aym_qunibi]

see this link
https://users.pandora.be\educypedia

 

[shedeed]

you can access a single bit in any port by masking the other bits using the bitwise XOR operator (^)
example
outport(0x378,0x05^0x6)
the follwoing configuration (0101 XOR 0110) will be output to port 0x378