!!! Linear screen area addressing

ZXNet echo conference «real.speccy»

From Ruslan Abdullaev To All 19 June 2004

Good afternoon to you, All.

Let's assume, hypothetically, that we have access to screen mode with
the following addressing.
H L
110ccccc yyyyyyyy

where c is the column number in familiar places (0-31)
y is the line number in pixels (0-191)

or, if we draw an analogy with standard addressing, this will
look like this:
H L
110ccccc ssrrrlll
where c is the column number in familiar places (0-31)
s - segment number (0-2)
r - row number (0-7)
l - line number (0-7)

What is the advantage of such addressing:
- transition to the next familiar place is carried out incrementing the high
byte, one line below - increasing the low byte. Such addressing
combines the advantages of standard and linear addressing, while
addressing is linear not by columns, but by lines.
#с000,#с100,#с200,...,#df00
#с001,#с101,#с201,...,#df01
..........................
#с0bf,#с1bf,#с2bf,...,#dfbf

- elementary calculation of the address specified both in familiar places and in
pixels.

- the size of the screen area will increase slightly, 8192 bytes, while
only 6144 bytes are used, the maximum possible resolution
with such addressing is 512*256 (64x256)

So, now let's forget the word "hypothetically", and think about how all
this can be implemented.

ra.id'mayhem

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