What if I mess up?

[Evan]

Do not do this code it's is a MASM that kinda went wrong ...

byte1 BYTE '0111h'

[dedndave]

 

BYTE's contain 8 bits
111h is 9 bits - you need at least a WORD

[Evan]

A word is bigger than a byte.

[dedndave]

BYTE, 8 bits
WORD, 16 bits
DWORD, 32 bits  (same size as REAL4)
QWORD, 64 bits  (same size as REAL8)
OWORD, 128 bits

TBYTE, 80 bits  (same size as REAL10)

[Evan]

Would

Code Select Expand

byte1 BYTE '0100h'
work?

[dedndave]

9 bits
0001 0000 0000

for 8 bits, the max is 0FFh
1111 1111

[dedndave]

you could use 2 bytes

Code Select Expand

    db 0,1
very similar to

Code Select Expand

    dw 100h

[Evan]

Would

Code Select Expand

byte1 BYTE '0100h'
work?

Is it this?
byte1 BYTE '0FFh'


or


byte1 BYTE 'FFh'

What does a full byte in hex look like?

Is 0xFF a full byte?

[Evan]

9 bits
0001 0000 0000

for 8 bits, the max is 0FFh
1111 1111

BYTE's contain 8 bits
111h is 9 bits - you need at least a WORD

Yes. If 8 bits is a byte.

:D


So 0xFF is like 99(base ten)


and my calculator says 256 or 255 base ten must be a full byte.

[dedndave]

a byte holds 8 bits, in common parlance

in binary
11111111
or
1111  1111

in hexadecimal
FF
or
0FFh

in decimal
255

the range for a signed byte is -128 to +127
the range for an unsigned byte is 0 to 255

[Evan]

a byte holds 8 bits, in common parlance

in binary
11111111
or
1111  1111

in hexadecimal
FF
or
0FFh

in decimal
255

the range for a signed byte is -128 to +127
the range for an unsigned byte is 0 to 255

How do I figure out the explanation of making negative numbers on the computer?


Is that how signing works somehow?

[Evan]

Is this it?
http://en.wikipedia.org/wiki/Signedness


Is this MASM friendly?
[quote source='wikipedia']For example, 0xFFFFFFFF gives −1, but 0xFFFFFFFFU gives 4,294,967,295 for 32-bit code.[/quote]


Would 0xFF be -1(base ten) and 0xFFU be 256(base ten) or 255(base ten)?


I would like to believe 0xFFU is 256(base ten) with all numbers being natural numbers including zero.

[sinsi]

Evan, you and dave seem to be talking about two different things.
This code works because it is a string due to using quotes

Code Select Expand

byte1 BYTE '0111h'
Without the quotes it is a number which is too big for a byte

Code Select Expand

byte1 BYTE 0111h

[dedndave]

hi sinsi - i saw the quotes - my assumption was that was how he got it to assemble without error
but, the intent was to define a value as hexadecimal - not a string

Evan - you may want to do some reading on basic data concepts
signed values normally use "two's compliment" form
you can google that term and find many descriptive texts

https://courses.engr.illinois.edu/ece390/books/artofasm/artofasm.html

start with chapter 1 - then, ask questions when something isn't clear   :t

you can put that url into translate.google.com and it will translate the entire site for you
by the way - what is your native language ???

[Evan]

hi sinsi - i saw the quotes - my assumption was that was how he got it to assemble without error
but, the intent was to define a value as hexadecimal - not a string

Evan - you may want to do some reading on basic data concepts
signed values normally use "two's compliment" form
you can google that term and find many descriptive texts

https://courses.engr.illinois.edu/ece390/books/artofasm/artofasm.html

start with chapter 1 - then, ask questions when something isn't clear   :t

you can put that url into translate.google.com and it will translate the entire site for you
by the way - what is your native language ???

Yeah well don't we always need a 0 in computers?
Does 0xFFU meaning 256(baseten) make sense?
Where I know that register is a positive one?
Including zero?


Or can I not use zero in this register and did my machine break?


Would my machine be okay if I don't use 0 in the register?


Do I then get to count up 1 to 256


Or can I count 0 to 256 in 0xFFU this whole time?
0 to 255
1 to 256
0 to 256


In 0xFFU
I am not sure.

Should I go with 0xFF meaning 255(baseten) and 0xFFU meaning ((-255 to 255))(base ten)?