LZ: Re: A little help needed


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LZ: Re: A little help needed



> From: Frank  <Jblaze77@msn.com>
> 
> Well i need a little help using the line algorthim to draw lines... can
anyone 
> help my problem is as follows:
> 
> when you use the starting points for the line algorithim are the numbers
in 
> hex? ex. $2020 is that the point 20,20 or do you need $07E4 for the point




EVERY number with a '$' in front of it (or an 'h' following it) is in hex. 
Also, '%' is for binary, and '@' is for octal.  Decimal numbers have
nothing in front of them.
Therefor $2020 is not 20,20, but 32,32.




> 20,20.... also how are 3 digit x values plotted?  In the documentation
for the 


3-digit x values are plotted just like 2-digit, becasue when using
hexadecimal numbers to plot points on the screen, you never need to use
numbers higher then 128, and hex numbers remain 2-digit up to 255 ($FF).


> line program the value $5430 is stored in de...
> 
> i am using the points stored as followed
> 
> .dw $2020,$2030 (this along with a routine to call the first in hl and
the 


when using a $, that signifies to the assembler that these numbers are in
hex, but your numbers here are in decimal (try $07E4 and $07EE).


> second in de, to draw the line 20,20--> 20,30 ...)
> 
> Is this right?


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