trying some ASM

[v3n0mn33dl3]

Hi all,

I was trying to do some ASM. Just to see how it works and learn some.

the questions I have are; How do I copy information to BEX? the value I get back is not what I expected, this is probably because in the ASM part it is a word and the BEX part is an integer. But what is the correct way?

I'm trying to copy the first 4 numbers of value 1 on over to value 2. So I'd expect value 3 to be 01233210....



Dim Value1 as Integer
Dim Value2 as Integer
Dim Value3 as Integer

on vblank gosub main
enable interrupt vblank
end

main:

gosub pieceOFasm

locate 0,0
print Value1

locate 2,0
print Value2

locate 4,0
print Value3


return

pieceOFasm:
asm
addi.w #$01234567,d0 ; put 01234567 into d0
move.w d0,(__INTEGER_Value1) ; copy to BEX
addi.w #$76543210,d1 ; put 76543210 into d1
move.w d1,(__INTEGER_Value2) ; copy to BEX
move.w d0,d1 ; put d0 into d1
move.w d1,(__INTEGER_Value3) ; copy to BEX
rts
end asm




[pico]

• A word is the exact same thing as a integer ~ your suspicion is incorrect.
• A word is only 16-bit, so the largest supported value is 65535 ~ your values are too big.
• A "#$" prefix indicates immediate hexadecimal data ~ not decimal.
• A addi operation adds a immediate value to the destination operand ~ not "put into".
• A word is a number, you can't just chop half of its notation off ~ unlike a string.

[Deleted]

Doing addi.w is adding that value to D0, so if D0 isn't 0, it'll be whatever value + the value you specified (1234567), so your second "addi.w" is actually D0+&h1234567+&h76543210, or D0+&h77777777.


       Dim value1 As Long, value2 As Long, value3 As Long
Asm
move.l #$01234567,(__LONG_value1)
move.l #$76543210, (__LONG_value2)
move.w (__LONG_value1),(__LONG_value2)
End Asm

Print Hex$(value1&)
Print Hex$(value2&)
Print value1&
Print value2&


Here's a good set of tutorials by MarkyJester: mrjester.hapisan.com/04_MC68/

[v3n0mn33dl3]

Thanks guys! This is really helpful!

Bummer I have to work this week..... So MarkyJester website has to wait... loads to read