Well THis is the Assembler Section Where you come to learn a bit of ASM OK..well you want to Know some assembler you came right place. I Cant promise youll be some ASM guru when you leave, but If you paid attention and under stodd you will know some assebler.. First Lets talk about the basics Assembler is a low level language meaning its hard to learn, High level languages (easier) are like Basic Now in assembler, when you use numbers, they wont be base 10, there base 16, in hexadecimal the Hex Number systemis as follows: base 10 (numbers u used to) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 base 16 (hex) 1h 2h 3h 4h 5h 6h 7h 8h 9h ah Bh ch dh eh fh 10h 11h 12h 13h 14h 15h 16h 17h 18h 19h 1ah 1bh 1ch See? thats how that works.. Now you must know that a CPU is made up of registers, a register is a place to store values, these will hold all of your variables (called offsets) the registers are AX (made up of ah and al) BX (bh and bl) CX (ch and cl) DX (dh and dl) ES DS CS SS SP Ok, the last 5 regiosters ES is the extra segment registers, where extra data is kept ahh wahst this word? segment, in ASM a segment is 64k bytes ofdata in length no larger. DS is the data segment, the segment where all the program data is kept in a program CS is code segment, where all the program code is kept SS is stack segment, all Programs have a stack, usually 1k, where values can be stored SP is the stack Pointer OK, with that off lets get coding. first We Will talk about Push/pop PUSH Syntax: push Ok, lets say we PUSH AX in a program What ever value AX hlds wil be stored on the stack, imagine the stack as a shelf to keep something on until u need to use it... Also if you push multiple values, the last one you push will be on the stack 1st example lets say i do this in a program: PUSH ax PUSH 4 PUSH 7 7 will be first on the stack.. so when i want to POP it off, the first pop ill use 7, the next 4, the next ax POP Syntax: POP nOW, LATER IN THE PROgram lets say you want to go the "shelf" Stack and retrieve a value, BUT THE VALUE U MUST BE FIRST ON STACK TO USE IT example lts say u: push 7 push 9 and want to put 7 in ax and u do this pop ax It wont be 7! because the 9 is on the stack before the 7 so it will be popped first got that down? Good Next is the MOV instruction it Movs a value into a register: Syntax: mov Example of its use mov ax,5 after this, ax will hold the value of 5 this can be done wiith most of the registers, but a few of the segment registers cant be manipulated this way Next improtant aprt, routine labeling yes you must label routines in your program, so they can be refrenced Lets say u have code to make a farty noise come out the speaker (lurance, dont get any ideas) you might have it like this: SpeakerFart: this is so you can reference this routine throughout the program, whioch brings me to my next section JMP (jump) these are used to hop around in your program, lets say u wanna go to the fartysound routine from another section of the program, u could add this line in when u wanna jump JMP FartyNoise that will jump and begin execution at routine labeled FartyNoise Now a lesson In memory addressing... in a PC comapitble system memory is adddressed in Segment:offset form ie: 0009:FFFF that says that the data at hand is 9h spot on segment and is at FFFFH in that segment Segments are 64k in length or 65,535 bytes FFFFh in hexadecimal when offset # is at ffffh and u add more to it, you up segment number when adding 1, it goes: 0009:ffffh 000a:0000h 000a:0001h and on. see? Which brings me to my next assembler command. LEA Load effective address this Loads the address of that offset into the register in question. and is used like this lea dx,[fart+5] this will load fart+5 into dx what are those brackets u ask? they tell the processor to combine everything in the brackets to one offset