... Your function would save the pixel lines being scrolled out of ... br />
Your buffer of pixel lines would be a block ... index pointing at the oldest pixel row. Then when you intercept the ... about to be scrolled off screen.

The actual ...

... screen. Following a halt there are ~14000 cycles to the top pixel ... raster is past the screen. With this in place ... the top of the screen but it's less ... start updating the top pixel row after the raster is ... the window is placed on screen.

In ...

... of screen file
ld bc,$18 ;0 into B; 8 pixel ... rows x 3 screen thirds into C
screen address
inc hl ;next screen address
djnz loop ...

... HASH LD HL,MainScreen ; screen address
LD B,12 ... screen file
ld bc,$18 ;0 into B; 8 pixel ... rows x 3 screen thirds into ... pattern into screen address
inc hl ;next screen address
...

... walk the screen column by column and row by row, blanking ... row;

/* Copy the ROM contents into the screen ... screen address of the character.*/

char_address = zx_cxy2saddr(col, row ... winking its way down the screen.

...

... 1): REM copy pixel row from a$() to screen
99 ... ro*co rectangle on screen
105 RESTORE 103 ... FN s$() to hold screen data
1991 GO ... />
2000 LOAD "" SCREEN$
2003 FOR p=0 ... 1)=s$: REM copy pixel row from screen to a$()
...

... is just on the title screen though, isn't it? ... left-to-right along one pixel row, then generating a random ... limit, you get a pixel. And you decrease that ... traces down the shape one pixel row at a time, works ... of the circle (on that pixel row) are given by -X ...

... read/writing to the screen once for every pixel.

And ... , I'm adding to the screen address (only when required) rather than ... be willing to sacrifice +-1 pixel endpoint accuracy for speed (e ... shallow slopes, work in 2-pixel steps). I can afford to ...

... up the screen.
(2) An algorithm that uses horizontal pixel scrolls ... few pixels from a single pixel row, and a vertical scroll that ... the back-buffer to the screen.

... up the screen.
(2) An algorithm that uses horizontal pixel scrolls ... few pixels from a single pixel row, and a vertical scroll that ... the back-buffer to the screen.[/quote]

Well there ... and right parts of the screen , like in the New wave ...

... point to the display file address


[code]
pixel line at a time. The ... BC, and copied to the screen address in HL.

... point to the display file address


[code]
pixel line at a time. The ... BC, and copied to the screen address in HL.

... alterations to the way a screen address is fetched as below.
row number. 0 being the top of the screen.
LD ... /> LD B,(HL)
RET ; screen address returned in BC
LNUM ...

... and it computes a screen address for every pixel visited. It also uses ... and it uses screen addresses rather than pixel coordinates so screen addresses don ... " and "10000000" respectively. The current screen address is modified to move up ...

... /> add hl, de ; hl = screen address of top row of char
ld ... e, (hl) ; e = low byte of screen address ... byte of screen address
ex de, hl ; hl = screen address of cell at ...

... /> add hl, de ; hl = screen address of top row of char
ld ... e, (hl) ; e = low byte of screen address ... byte of screen address
ex de, hl ; hl = screen address of cell at ...

... /> add hl, de ; hl = screen address of top row of char
ld ... e, (hl) ; e = low byte of screen address ... byte of screen address
ex de, hl ; hl = screen address of cell at ...

... /> add hl, de ; hl = screen address of top row of char
ld ... e, (hl) ; e = low byte of screen address ... byte of screen address
ex de, hl ; hl = screen address of cell at ...

... /> add hl, de ; hl = screen address of top row of char
ld ... e, (hl) ; e = low byte of screen address ... byte of screen address
ex de, hl ; hl = screen address of cell at ...

... /> add hl, de ; hl = screen address of top row of char
ld ... e, (hl) ; e = low byte of screen address ... byte of screen address
ex de, hl ; hl = screen address of cell at ...

... /> add hl, de ; hl = screen address of top row of char
ld ... e, (hl) ; e = low byte of screen address ... byte of screen address
ex de, hl ; hl = screen address of cell at ...

... arbitrary row but aligned to a column, one which calculates the screen address ... looks up the screen address from a table each row.

I ... 8x8 sprite anywhere on the screen (except if it goes off ... the screen).

I'll ...

... 't like this

; screen address table. This must be 256 ... strips not 2 bytes per row... must have been drunk when ...

... /> add hl, de ; hl = screen address of top row of char
ld ... e, (hl) ; e = low byte of screen address ... byte of screen address
ex de, hl ; hl = screen address of cell at ...

... checkerboard pattern at column 31, row 23
ld hl, checkerboard ...

... +3)
cp 23 ;check row
jr c,wearefine
row 23
ld hl, checkerboard ...

... (ix+3), 18 ; and the row to 18
airloop ; ld ...
; NEED TO DO THE ROW CHECK BEFORE CALLING text_out
cp 24 ;check row < 24 before calling text_out ... checkerboard pattern at column 31, row 23
ld hl, checkerboard ...

... (ix+3), 0 ; and the row to 18
airloop ; ld ...
; NEED TO DO THE ROW CHECK BEFORE CALLING text_out
cp 24 ;check row < 24 before calling text_out ... checkerboard pattern at column 31, row 23
ld a,5 ...

...
; convert row -> offset of row in screentable (= tbl_scraddr + row*16)
; look up screen address from the table
ld ...
; convert row -> offset of row in screentable (= tbl_scraddr + row*16)