LESSON10 - PORTS, TIPS, SUMMARY

the way of the computer to communicate with it's cards is through the

ports, lets say the screen data port is 3dah and the keyboard port

is 60h,64h

IN al,port ; al recieves the value in port

OUT port,al ; port recieves the value in al

basic listing of ports (can't get it on a list) :

0-7 : dma base ports

20h : pic, interrupt aknowlege

21h : interrupt masking port

40h : timer port

43h : timer init port

60h : keyboard keys port

64h : keyboard control port

3c8h : screen pal port

3dah : screen data port

and there are more, non significent or that I don't know (and there a lot)

TIPS :

- never use a source that don't know what it does.

- take sources and learn them.

- learn to use any debug program.

- assembly is a language that every mistake can be important and the computer

may hang, so don't give up.

- use qemm is traps errors that you won't know .

- get an interrupt list (very very important).

- don't be a lamer.

SUMMARY :

you have learned in those quick 10 lessons, to code in assembly - this

is realy the basic, currenly you can't do much but the hard work

is behind you.

now you will just have to learn the technics (no shortage of those)

and maybe some day you will right a better guide than this.

good programing to you all.

reminder : don't be one of those lamers that uses lots of units/lib and

say you are a good programmer, do it yourself that's the

trick.