i/o addresses

djdominos

hey guys,
first off let me say great site, its been really helpful. I was just wondering what i/o addresses i should know for the hardware exam? and does anybody have any techniques to memorizing them?

RidiculousOne

The ones I know are:

Keyboard
Floppy Drive
Two hard drive controllers
COM1-COM4
LPT1&LPT2

I memorized COM1-4 and LPT1&LPT2 by using a set of rules.
A good way to memorize the COM and LPT I/Os is to list the COM ports in order as such

COM1
COM2
COM3
COM4
LPT1
LPT2

Then list an alternating pattern of 323232 down for the first digit on each of them as such

COM1 3
COM2 2
COM3 3
COM4 2
LPT1 3
LPT2 2

Then list an alternating pattern of FFEE down for the second digit on the COMs as such

COM1 3F
COM2 2F
COM3 3E
COM4 2E
LPT1 3
LPT2 2

Then put an '8' at the end of the COMs and a '78' at the end of the LPTs as such.

COM1 3F8
COM2 2F8
COM3 3E8
COM4 2E8
LPT1 378
LPT2 278

When all of them are complete, do remember to put a lowercase 'h' at the end of them to indicate that they are a hexadecimal address.

COM1 3F8h
COM2 2F8h
COM3 3E8h
COM4 2E8h
LPT1 378h
LPT2 278h


Additional I/Os:
Keyboard is 60h
Floppy Controller is 3F0h
1st HDD Controller is 1F0h
2nd HDD Controller is 170h

I did assembly programming for ATAPI Device Identification and such..so thats how I knew the hard drive controllers...and I've messed with sending printer commands through I/O 378 so thats how I know the Printer...and I've debugged a program that sent status signals (kinda like the post routine) to the keyboard...so thats how I knew the keyboard.

However, enough with my ranting. I hope the part on the COM's helps you. The others I have not simple trick for...its just memorizing

jlambert

excellent info. I will have to remember that for when I start studying for A+