this program doesnt work, it just says b integer out of range:
Code: Select all
org 40000
; We want a black screen.
ld a,71 ; white ink (7) on black paper (0),
; bright (64).
ld (23693),a ; set our screen colours.
xor a ; quick way to load accumulator with zero.
call 8859 ; set permanent border colours.
; Set up the graphics.
ld hl,blocks ; address of user-defined graphics data.
ld (23675),hl ; make UDGs point to it.
; Okay, let's start the game.
call 3503 ; ROM routine - clears screen, opens chan 2.
; Initialise coordinates.
ld hl,21+15*256 ; load hl pair with starting coords.
ld (plx),hl ; set player coords.
call basexy ; set the x and y positions of the player.
call splayr ; show player base symbol.
; This is the main loop.
mloop equ $
; Delete the player.
call basexy ; set the x and y positions of the player.
call wspace ; display space over player.
; Now we've deleted the player we can move him before redisplaying him
; at his new coordinates.
ld bc,63486 ; keyboard row 1-5/joystick port 2.
in a,(c) ; see what keys are pressed.
rra ; outermost bit = key 1.
push af ; remember the value.
call nc,mpl ; it's being pressed, move left.
pop af ; restore accumulator.
rra ; next bit along (value 2) = key 2.
push af ; remember the value.
call nc,mpr ; being pressed, so move right.
pop af ; restore accumulator.
rra ; next bit (value 4) = key 3.
push af ; remember the value.
call nc,mpd ; being pressed, so move down.
pop af ; restore accumulator.
rra ; next bit (value 8) reads key 4.
call nc,mpu ; it's being pressed, move up.
; Now he's moved we can redisplay the player.
call basexy ; set the x and y positions of the player.
call splayr ; show player.
halt ; delay.
; Jump back to beginning of main loop.
jp mloop
; Move player left.
mpl ld hl,ply ; remember, y is the horizontal coord!
ld a,(hl) ; what's the current value?
and a ; is it zero?
ret z ; yes - we can't go any further left.
dec (hl) ; subtract 1 from y coordinate.
ret
; Move player right.
mpr ld hl,ply ; remember, y is the horizontal coord!
ld a,(hl) ; what's the current value?
cp 31 ; is it at the right edge (31)?
ret z ; yes - we can't go any further left.
inc (hl) ; add 1 to y coordinate.
ret
; Move player up.
mpu ld hl,plx ; remember, x is the vertical coord!
ld a,(hl) ; what's the current value?
cp 4 ; is it at upper limit (4)?
ret z ; yes - we can go no further then.
dec (hl) ; subtract 1 from x coordinate.
ret
; Move player down.
mpd ld hl,plx ; remember, x is the vertical coord!
ld a,(hl) ; what's the current value?
cp 21 ; is it already at the bottom (21)?
ret z ; yes - we can't go down any more.
inc (hl) ; add 1 to x coordinate.
ret
; Set up the x and y coordinates for the player's gunbase position,
; this routine is called prior to display and deletion of gunbase.
basexy ld a,22 ; AT code.
rst 16
ld a,(plx) ; player vertical coord.
rst 16 ; set vertical position of player.
ld a,(ply) ; player's horizontal position.
rst 16 ; set the horizontal coord.
ret
; Show player at current print position.
splayr ld a,69 ; cyan ink (5) on black paper (0),
; bright (64).
ld (23695),a ; set our temporary screen colours.
ld a,144 ; ASCII code for User Defined Graphic 'A'.
rst 16 ; draw player.
ret
wspace ld a,71 ; white ink (7) on black paper (0),
; bright (64).
ld (23695),a ; set our temporary screen colours.
ld a,32 ; SPACE character.
rst 16 ; display space.
ret
plx defb 0 ; player's x coordinate.
ply defb 0 ; player's y coordinate.
; UDG graphics.
blocks defb 16,16,56,56,124,124,254,254 ; player base.
