On 3 Sep 2009, at 09:25, Andrew Park wrote:
Hello
I want to use JPUT (&0133) to display my graphics to compare speed
with my own routine, on a 512K Sam where is the default screen page
stored?
I understand that as long as the graphics are between 16384 and
32767 or above 57344 in the screen page that should be fine but
where in the 512k memory is the default screen page? I’ve calculated
where it is but what i can see is it goes past the 512k boundary so
loses the data.
The screen will be in pages 30 and 31 by default. In modes 3 and 4 the
screen is 24k in size, so the address of the top of the screen will be
at offset 8192 in page 31.
Because BASIC starts page 0 at the address 16384, the BASIC address of
the top of the screen will be at (31+1)*16384 + 8192 = 532480.
Andrew
