version 0.5: moving enemies, some fixes
[nemesis.git] / nemesis.z80
index b735b9c0860f4c417e9a3ccdcf11f75c1efa555a..cb0f3eb21bea232724637aff9ddf31d64a9177db 100644 (file)
@@ -6,61 +6,30 @@
 
        nop
        jp  Start
-       .dw $0000
+       .dw $0001
        .dw Title
-Title: .db "Nemesis v0.3.719 by Shiar",0
+       .dw spr_ship
+Title: .db "Nemesis v0.5.725 by Shiar",0
 Start:
        jr init
 
 just_fired     = $c0f9         ;byte
 temp1          = $c100         ;word
 
-;-------------------- init ----------------------------------------------------
+;---------------------- init --------------------------------------------------
 
 init:
        call _runindicoff
 
-;-------------------- main menu -----------------------------------------------
+;---------------------- main menu ---------------------------------------------
 
-       jp play_game
-
-;-------------------- exit ----------------------------------------------------
-
-exit_game:
-       ret
-
-;----------------------- game setup -------------------------------------------
+;---------------------- game setup --------------------------------------------
 
 play_game:
-       ld  hl,stored_data_start
-       ld  bc,variables_end-stored_data_start-1
-
-;---------------------- display setup ----------------------------------------
-
-set_up_display:
-       call _clrLCD
-
-       ld  hl,in_game_text
-       ld  b,3
-l11:   ld  a,(hl)
-       ld  (_curCol),a
-       inc hl
-       ld  a,(hl)
-       ld  (_curRow),a
-       inc hl
-       call _puts
-       djnz l11
-
-in_game_text:
-       .db 16,0,"LIVES",0
-       .db 16,3,"LEVEL",0
-       .db 16,6,"SCORE",0
-
-str_question:
-       .db "-----",0
+       call Next_level
 
 ;------------------------------------------------------------------------------
-;-------------------------- game loop -----------------------------------------
+;---------------------- game loop ---------------------------------------------
 ;------------------------------------------------------------------------------
 
 game_main_loop:
@@ -71,7 +40,6 @@ Clear_screen:
        xor a
        ld  hl,GRAPH_MEM+(16*12)
        ld  b,a
- ld a,(background)
 clearloop:
        ld  (hl),a
        inc hl
@@ -94,10 +62,9 @@ game_stuff:
        call Level_event        ;insert enemies
        call Handle_Ship        ;move you
        call Fire_bullet        ;check for fire
-       call Handle_bullets     ;move bullets
        call Handle_enemies     ;move enemies
-       call Enemy_fires        ;check for enemy fire
-       call Enemy_bullets      ;move bullets
+       call Handle_bullets     ;move your bullets
+       call Enemy_bullets      ;move enemy bullets
        call Enemies_hit        ;check for collision with enemies
 
        call Display_Screen     ;display all
@@ -122,10 +89,11 @@ displayloop:
        dec a
        jr  nz,displayloop
 
-;      ld  hl,$1007            ;Display Score
-;      ld  (_curRow),hl
-;      ld  hl,(score)
-;      jp  _D_HL_DECI
+       ld  hl,$1006            ;Display Score
+       ld  (_curRow),hl
+       ld  hl,(timer)
+       ld  h,0
+       jp  _D_HL_DECI
        ret
 
 ;------------------------- handle ship ----------------------------------------
@@ -135,14 +103,14 @@ Handle_Ship:
        or  a
        jr  z,ok                ;0 = normal stat
 
-;      dec a
-;      ld  (your_status),a
-;      ld  hl,(lives)
-;      ld  a,l
-;      or  h
-;      jr  nz,ok
-;      pop af
-;      ret
+       inc a                   ;next (explosion)frame
+       ld  (your_occ),a        ;save
+
+       cp  34                  ;last explosion frame?
+       jr  c,exploding_you     ;not yet: display explosion
+       cp  54                  ;delay finished?
+       jp  z,game_over         ;yes = game over
+       ret                     ;don't display anything
 
 ok:
        ld  a,%01111110
@@ -184,20 +152,16 @@ no_right:
        cp  15                  ;y > 15
        jr  z,no_up
        ld  (hl),a
-no_up: ld  ix,spr_ship
+no_up: ld  ix,spr_ship01
 
 display_common:
        ld  e,(hl)
-       jp  drw_spr
+       jp  drw_spr             ;ret
 
-;you_not_normal:
-;      ld       a,(your_status)
-;      dec      a
-;      ld       (your_status),a
-;      inc      a
-;      and      14
-;      xor      14
-;      ld       hl,x-1
+exploding_you:
+       srl a                   ;half the framerate
+       dec a                   ;first frame is 1>inc>srl>dec = 0
+       ld  hl,x-1
 
 explosion_stuff:
        rra
@@ -214,8 +178,8 @@ explosion_stuff:
        jr  display_common
 
 damage_you:
-       or  %10101010
-       ld  (background),a
+       ld  a,1                 ;set to explode (1st frame)
+       ld  (your_occ),a
        ret
 
 ;------------------------- fire bullet ----------------------------------------
@@ -302,15 +266,15 @@ bullet_type1:
        push de
        call drw_spr            ;display bullet
        pop de
-       ld  b,20
+       ld  b,nrenemies
        ld  hl,enemies
 
 hit_enemies:                   ;Hits with normal enemies
        push hl
 
        ld  a,(hl)
-       and %00000001
-       jr  z,nohit             ;no hit when enemy_occ <> 1
+       and %00000010
+       jr  z,nohit             ;no hit when enemy_occ <> 2/3
 
        inc hl
        inc hl
@@ -339,20 +303,19 @@ hit_enemies:                      ;Hits with normal enemies
        dec hl
        dec hl
        ld  a,(hl)              ;occ
+       ld  b,a                 ;push occ
        srl a
        srl a                   ;occ/4 = HP left
        jr  nz,hpleft
-       ld  (hl),2              ;set to explode
+       ld  (hl),$01            ;set to explode
        inc hl
        ld  (hl),a              ;explosionFrame 0
        pop hl
        ret
 
 hpleft:
-       dec a
-       add a,a
-       add a,a 
-       inc a                   ;HP*4+1 = occ 1
+       ld  a,b                 ;pop occ
+       sub %00000100           ;decrease HP by one
        ld  (hl),a              ;save
        pop hl
        ret
@@ -383,26 +346,26 @@ chk_noenemy:
        inc de
        inc de
        ld  a,(de)
-       or  a
+       or  a                   ;0 = no enemy present
        jr  nz,chk_noenemy
 
-       inc de
-       ld  a,(hl)
-       ld  (de),a              ;type
+       ld  a,(hl)              ;type
        ld  hl,enemy01
        ld  c,a
        ld  b,0
        add hl,bc
        add hl,bc
        add hl,bc               ;hl = enemy specs
-       dec de
-       ld  a,(hl)              ;load hitpoints
-       or  1                   ;set type 1 (normal) enemy
+       ld  a,(hl)              ;load hitpoints+occ of this enemy class
        ld  (de),a              ;occ
 
+       inc hl
        inc de
+       ld  a,(hl)              ;load movement+type of this enemy class
+       ld  (de),a              ;type
+
        inc de
-       ld  a,$5a
+       ld  a,$5a               ;appear at right edge of screen
        ld  (de),a              ;x
        inc de
 
@@ -411,45 +374,25 @@ chk_noenemy:
        ld  a,(hl)
        ld  (de),a              ;y
 
-       inc hl                  ;+0
+       inc hl                  ;@ next event
        ld  a,(hl)
-       cp  $ff
+       cp  $ff                 ;255 = end marker
        jp  z,Next_level
-       ld  (nextevent),a
+       ld  (nextevent),a       ;else time to next event
 
        inc hl
-       ld  (curevent),hl
-       ret
+       ld  (curevent),hl       ;update pointer
 
-;--------------------------- enemy fires --------------------------------------
+       or  a                   ;no delay
+       jr  z,do_event
+       ret                     ;no more events for now
 
-Enemy_fires:
-       ld  a,r
-       and %01111111
-       cp  19
-       ret p
+;--------------------------- enemy fires --------------------------------------
 
-       add a,a
-       add a,a
-       ld  c,a
-       ld  b,0                 ;bc = a*4
-       ld  hl,enemies
-       add hl,bc               ;hl = enemy
-       ld  a,(hl)
-       or  a
-       ret z                   ;return if no enemy
-       dec a
-       dec a
-       ret z                   ;or exploding enemy
-       inc hl
-       inc hl
-       ld  c,(hl)              ;enemy x-pos
-       dec c
-       dec c                   ;c = x-2
-       inc hl
-       ld  a,(hl)              ;y-pos
-       add a,5
-       ld  e,a                 ;e = y+5
+Enemy_fires:                   ;de = x,y
+       dec d
+       dec d                   ;d = x-2
+       inc e                   ;e = y+1
 
        ld  b,10
        ld  hl,ebullets
@@ -466,7 +409,7 @@ find_ebullet:
 found_ebullet:
        ld  (hl),1              ;use bullet
        inc hl
-       ld  (hl),c              ;set x-pos
+       ld  (hl),d              ;set x-pos
        inc hl
        ld  (hl),e              ;set y-pos
        ret         
@@ -491,7 +434,6 @@ next_bullet:
        djnz handle_bullet
        ret
 
-
 enemy_bullet:
        inc hl
        ld  a,(hl)              ;bullet x
@@ -529,9 +471,7 @@ enemy_bullet:
        jr  nc,next_bullet
 
        call damage_you         ;HIT!!
-
 remove_ebullet:
-       dec hl
        dec hl
        ld   (hl),0             ;bullet > unused
        jr   next_bullet
@@ -540,7 +480,7 @@ remove_ebullet:
 
 Handle_enemies:
        ld  hl,enemies
-       ld  b,20
+       ld  b,nrenemies         ;loop 20x
 
 handle_enemy:
        push bc
@@ -549,44 +489,96 @@ handle_enemy:
        ld  a,(hl)
        and %00000011
        jr  z,next_enemy        ;occ "no enemy" 0
-       and %00000001
-       jr  z,exploding_enemy   ;occ "exploding" 2
+       dec a
+       jr  z,exploding_enemy   ;occ "exploding" 1
+       ld  b,1
+       dec a
+       jr  z,normal_enemy      ;occ "normal" 2
 
-normal_enemy:                  ;occ "normal" 1
+moving_enemy:                  ;occ "moving" 3
+       ld  b,0
+
+normal_enemy:
        inc hl
        ld  a,(hl)              ;type
+       and %11100000           ;move-type
+       add a,b                 ;add move bit from occ
+       ld  b,a                 ;save in b
+       ld  a,(hl)              ;type
        add a,a
        add a,a
        add a,a
        ld  c,a                 ;type*8 = offset
+
        inc hl
-       ld  d,(hl)              ;x
+       ld  a,(hl)              ;x
+       dec a                   ;move left
+       jp  m,remove_enemy      ;off screen
+       jr  z,remove_enemy      ;"
+       ld  d,a
+
        inc hl
        ld  e,(hl)              ;y
-
-       ld  a,d
-       or  a
-       jr  z,next_enemy
+       ld  a,b                 ;%xxx00001=moving -0=normal
        dec a
-       ld  d,a
-       jr  z,remove_enemy
-
-       ld  (hl),e
-       dec hl
-       ld  (hl),d
+       jr  z,ymove_done        ;skip y-move
+
+;      srl a
+;      ld  b,a                 ;b = %0xxx0000 (move stat)
+       ld  a,(timer)
+       and %00010000           ;switches 0<>1 every 16 turns
+;      add a,b                 ;a = new move stat
+;      add a,a
+;      ld  b,a                 ;b = %xxx00000 (new move stat*2)
+
+;      dec hl \ dec hl
+;      ld  a,(hl)              ;type
+;      and %00011111           ;reset move-type
+;      add a,b                 ;set new move-type
+;      ld  (hl),a
+;      inc hl \ inc hl         ;@y
+
+;      and %00100000
+       jr  z,movedown
+moveup:        dec (hl)                ;decrease y-pos
+       jr ymove_done
+movedown:
+       inc (hl)                ;increase y-pos
+
+ymove_done:
+       dec hl                  ;@x
+       ld  (hl),d              ;store new x
        ld  ix,spr_enemy01
        ld  b,$00
        add ix,bc
-       call drw_spr
-       jr  next_enemy
+
+;      push hl                 ;save registers
+       push de
+       call drw_spr            ;display
+       pop  de                 ;restore (destroyed by drw_spr)
+;      pop  hl
+
+;      dec hl
+;      ld  b,(hl)              ;type
+;      and %00011111           ;enemy class
+;      ld  hl,enemy01          ;all enemies' specs
+;      inc b                   ;next enemy's specs
+;      ld  c,$00
+;      add hl,bc
+;      add hl,bc
+;      add hl,bc               ;go there
+;      dec hl                  ;last byte of this enemy's specs
+
+       ld  a,$ff               ;fire frequency
+       call Random             ;random value < a
+       dec a                   ;fire if 1
+       call z,Enemy_fires      ;fires bullet
+       jr   next_enemy
 
 remove_enemy:
-       dec hl
-       dec hl
-enemy_gone:
-       dec hl
+       pop hl
        ld  (hl),$0000          ;bye bye enemy
-
+       push hl
 next_enemy:
        pop hl
        ld  bc,$0004
@@ -604,7 +596,7 @@ exploding_enemy:
 
        ld  a,(hl)
        cp  15
-       jr  z,enemy_gone        ;remove when at last frame
+       jr  z,remove_enemy      ;remove when at last frame
        inc a
        ld  (hl),a              ;next frame
        jr  next_enemy
@@ -613,55 +605,126 @@ exploding_enemy:
 
 Enemies_hit:
        ld  a,(your_occ)
-       or  a
+       or  a                   ;0 = you're normal
        ret nz
 
        ld  de,(x)              ;e = X, d = Y
-       ld  hl,enemies-4
-check_next:
-       ld  bc,$0004
-       add hl,bc
-
-       ld  a,(hl)
-       cp  $ff
-       ret z                   ;-1 = no more enemies
+       ld  hl,enemies
+       ld  b,nrenemies         ;check all 20 enemies
+check_collision:
        push hl
-       cp  1
-       jr  nz,nocrash          ;1 = enemy
+       ld  a,(hl)
+       and %00000010
+       jr  z,check_next        ;2/3 = ok
 
        inc hl
        inc hl
        ld  a,(hl)              ;check x match
        sub e
        add a,6
-       jp  m,nocrash
+       jp  m,check_next
        cp  12
-       jr  nc,nocrash
+       jr  nc,check_next
 
        inc hl
        ld  a,(hl)              ;check y match
        sub d
        add a,6
-       jp  m,nocrash
+       jp  m,check_next
        cp  12
-       jr  nc,nocrash
+       jr  nc,check_next
 
        dec hl
        dec hl
-       ld  (hl),0              ;explosionFrame 0
+       xor a
+       ld  (hl),a              ;explosionFrame 0
        dec hl
-       ld  (hl),2              ;set to explode
-       call damage_you
+       inc a
+       ld  (hl),a              ;set to explode
+       call damage_you         ;auch!
 
-nocrash:
+check_next:
        pop hl
-       jr  check_next
+       inc hl
+       inc hl
+       inc hl
+       inc hl
+       djnz check_collision
+       ret
 
 ;--------------------------- next level ---------------------------------------
 
 Next_level:
-       ld  hl,Leveldata+1
+       ld  hl,Leveldata+1      ;reset level data
+       ld  (curevent),hl
+
+       call _clrLCD            ;clear screen
+       ld  hl,$0703
+       ld  (_curRow),hl        ;center
+       ld  hl,txt_level
+       call _puts              ;display "LEVEL "
+
+       ld  a,(level)
+       inc a                   ;increase level nr.
+       ld  (level),a
+       ld  l,a
+       ld  h,$00
+
+       call UNPACK_HL
+       add a,'0'
+       ld  b,a
+       call UNPACK_HL
+       add a,'0'
+       call _putc              ;display second digit
+       ld  a,b
+       call _putc              ;display first digit
+
+       ld  b,$20
+wait:  halt \ halt
+       djnz wait               ;delay
+       call _getkey            ;wait for keypress
+       jr  game_setup          ;prepare display and vars
+       ret
+
+;--------------------------- game over ----------------------------------------
+
+game_over:
+       ld  hl,Leveldata+1      ;reset level data
        ld  (curevent),hl
+
+       call _clrLCD            ;clear screen
+       ld  hl,$0603
+       ld  (_curRow),hl        ;center
+       ld  hl,txt_gameover
+       call _puts              ;display "GAME OVER"
+
+       ld  b,$20
+wait2: halt \ halt
+       djnz wait2              ;delay
+       call _getkey            ;wait for keypress
+       jr  game_setup          ;prepare display and vars
+       ret
+
+;---------------------- setup game --------------------------------------------
+
+game_setup:
+       call _clrLCD
+       ld  hl,$1005
+       ld  (_curRow),hl
+       ld  hl,txt_score        ;display "SCORE"
+       call _puts                      ;display texts
+
+       xor a
+       ld  (timer),a                   ;reset time
+       ld  (level),a                   ;level 1
+       ld  hl,Leveldata+1
+       ld  (curevent),hl               ;reset level
+       ld  hl,(Leveldata)
+       ld  (nextevent),hl
+                                       ;ret
+;---------------------- exit --------------------------------------------------
+
+exit_game:
        ret
 
 ;--------------------------- putsprite ----------------------------------------
@@ -721,7 +784,28 @@ _notedge:djnz _iloop
        djnz _oloop
        ret
 
-
+;---------------------- random ------------------------------------------------
+
+Random:               ; Creates a random number 0 <= x < A
+ push bc
+ push de
+ push hl
+ ld b,a
+ ld a,r
+ add a,a
+ ld hl,0
+ ld d,0
+ ld e,a
+RMul:
+ add hl,de
+ djnz RMul
+ ld a,h
+ pop hl
+ pop de
+ pop bc
+ ret
+
+;------------------------
 
 _D_HL_DECI:
          push     bc
@@ -752,7 +836,19 @@ up_data: .db      "PAD98",0
 ;------------------------------- sprites --------------------------------------
 
 spr_ship:
-       .db 7,7         ;your ship:
+       .db 9,1         ;ship icon
+       .db %11100000   ; ███
+       .db %11111000   ; █████
+       .db %00111110   ;   █████
+       .db %11111001   ; █████  █
+       .db %11111101   ; ██████ █
+       .db %11111001   ; █████  █
+       .db %00111110   ;   █████
+       .db %11111000   ; █████
+       .db %11100000   ; ███
+
+spr_ship01:
+       .db 7,7         ;ship alpha class
        .db %01110000   ;  ███
        .db %11100000   ; ███
        .db %11111100   ; ██████
@@ -760,6 +856,15 @@ spr_ship:
        .db %11111100   ; ██████
        .db %11100000   ; ███
        .db %01110000   ;  ███
+spr_ship02:
+       .db 7,7         ;ship beta class
+       .db %11000000   ; ██
+       .db %11110000   ; ████
+       .db %01111100   ;  █████
+       .db %01110010   ;  ███  █
+       .db %01111100   ;  █████
+       .db %11110000   ; ████
+       .db %11000000   ; ██
 
 spr_bullet01:
        .db 5,3         ;your bullets
@@ -778,181 +883,262 @@ spr_bullet11:
        .db %11100000   ; ███▓▒░
        .db %01000000   ;  █▓▒░
 
-spr_enemy01:
-       .db 6,6         ;enemy type one
-       .db %00111100   ;   ████
-       .db %01110000   ;  ███
-       .db %11110000   ; ████
-       .db %11110000   ; ████
-       .db %01110000   ;  ███
-       .db %00111100   ;   ████
-spr_enemy02:
-       .db 6,6         ;enemy type two
-       .db %01111100   ;  █████
-       .db %11110000   ; ████
-       .db %10111000   ; █ ███
-       .db %10111000   ; █ ███
-       .db %11110000   ; ████
-       .db %01111100   ;  █████
-spr_enemy03:
-       .db 6,6         ;enemy type three
-       .db %00111000   ;   ███
-       .db %01111100   ;  █████
-       .db %11111000   ; █████
-       .db %11111000   ; █████
-       .db %01111100   ;  █████
-       .db %00111000   ;   ███
-spr_enemy03:
-       .db 6,6         ;enemy type three
-       .db %00111000   ; ███
-       .db %01111100   ;   ██
-       .db %11111000   ; █████
-       .db %11111000   ; █████
-       .db %01111100   ;  █████
-       .db %00111000   ; ███
-
 spr_explosion:                               
        .db 8,6         ;1
        .db %00000000
-       .db %00011100
-       .db %00111110
-       .db %01010110
-       .db %00111000
+       .db %00011100   ;    ███
+       .db %00111110   ;   █████
+       .db %01010110   ;  █ █ ██
+       .db %00111000   ;   ███
        .db %00000000
 
        .db 8,6         ;2
-       .db %00110000
-       .db %01001110
-       .db %10111110
-       .db %01001111
-       .db %00111000
-       .db %00011010
+       .db %00110000   ;   ██
+       .db %01001110   ;  █ ▒███
+       .db %10111110   ; █ █████
+       .db %01001111   ;  █ ▒████
+       .db %00111000   ;   ███
+       .db %00011010   ;    ██ █
 
        .db 8,6         ;3
-       .db %11110011
-       .db %01001110
-       .db %10110101
-       .db %01000101
-       .db %00111110
-       .db %11011010
+       .db %10110011   ; █ ██  ██
+       .db %01001110   ;  █  ███
+       .db %10110101   ; █ ██▒█▒█
+       .db %01000101   ;  █  ▒█▒█
+       .db %00111110   ;   █████
+       .db %11011010   ; ██ ██ █
 
        .db 8,6         ;4
-       .db %11110010
-       .db %01001110
-       .db %10110101
-       .db %01000101
-       .db %00111110
-       .db %01011010
+       .db %00101010   ; ▒ █▒█ █▒
+       .db %01000110   ;  █  ▒██
+       .db %10110101   ; █ ██ █ █
+       .db %01100110   ;  ██  ██▒
+       .db %00111100   ;   ████▒
+       .db %01011001   ; ▒█ ██ ▒█
 
        .db 8,6         ;5
-       .db %01000001
-       .db %00100110
-       .db %00010101
-       .db %01000100
-       .db %00010010
-       .db %10011010
+       .db %01000001   ;  █▒ ▒ ▒█
+       .db %00100101   ;  ▒█  █▒█
+       .db %00010100   ; ▒ ▒█ █ ▒
+       .db %01000100   ;  █▒  █
+       .db %00010010   ;   ▒█▒▒█
+       .db %10011010   ; █▒ ██ █▒
 
        .db 8,6         ;6
-       .db %01000100
-       .db %00100000
-       .db %00000001
-       .db %01000100
-       .db %00100010
-       .db %10001000
+       .db %01000100   ;  █   █ ▒
+       .db %00100000   ;   ▒█ ▒ ▒
+       .db %00000001   ;    ▒ ▒ █
+       .db %01000100   ;  █   █
+       .db %00100010   ;   █▒  █
+       .db %01001000   ; ▒█ ▒█ ▒
 
        .db 8,6         ;7
-       .db %00001000
-       .db %11000010
-       .db %00000000
-       .db %00100000
-       .db %00000001
-       .db %00110000
+       .db %00001000   ;  ▒  █▒
+       .db %11000010   ; ██ ▒  █
+       .db %00000000   ;        ▒
+       .db %00100000   ;  ▒█  ▒
+       .db %00000001   ;   ▒   ▒█
+       .db %00110000   ;  ▒██▒
 
        .db 8,6         ;8
-       .db %00000100
-       .db %00000000
-       .db %01000000
-       .db %00000000
-       .db %00000001
-       .db %00100100
-
-;---------------------------- enemy types -------------------------------------
-
-enemy01:       .db %00000000,$ff,$ff           ;$hits   $fire frequency
-enemy02:       .db %00000100,$ff,$ff
-enemy03:       .db %00001000,$ff,$ff
-
-;---------------------------- level data --------------------------------------
-
-Leveldata:
-       .db $01,$01,$40         ;$time (ff=end)    $type    $y-pos
-       .db $10,$00,$30
-       .db $10,$02,$20
-       .db $40,$01,$10
-       .db $01,$00,$44
-       .db $15,$01,$31
-       .db $04,$02,$38
-       .db $05,$00,$40
-       .db $03,$00,$2f
-       .db $04,$00,$3a
-       .db $12,$00,$10
-       .db $10,$00,$18
-       .db $0e,$00,$20
-       .db $0c,$00,$28
-       .db $0a,$00,$30
-       .db $08,$00,$38
-       .db $06,$00,$40
-       .db $04,$00,$48
-       .db $2a,$00,$20
-       .db $ff,$ff,$ff
+       .db %00000100   ;     ▒█
+       .db %00000000   ; ▒▒    ▒
+       .db %01000000   ;  █
+       .db %00000000   ;   ▒
+       .db %00000010   ;       █▒
+       .db %00100100   ;   █▒ █
+
+spr_icon01:
+       .db 5,4
+       .db %00100000   ;   █
+       .db %10101000   ; █ █ █
+       .db %11111000   ; █████
+       .db %01110000   ;  ███
+spr_icon02:
+       .db 5,4
+       .db %00000000   ;  ███
+       .db %00000000   ; ██ ██
+       .db %00000000   ; █   █
+       .db %00000000   ;
 
 ;---------------------------- texts -------------------------------------------
 
-title_message:
-         .db      "* * NEMESIS * *",0
+txt_title:     .db "* * NEMESIS * *",0
+txt_level:     .db "LEVEL ",0
+txt_gameover:  .db "GAME OVER!",0
+txt_score:     .db "SCORE",0
 
 ;---------------------------- save data ---------------------------------------
 
 stored_data_start:
 
-level          .dw $0000               ;level number
-background     .db %00000001           ;level background
-timer          .dw $0000
+level          .db $00                 ;level number
+timer          .db $00                 ;frame counter
 curevent       .dw Leveldata+1         ;next event
 nextevent      .db (Leveldata)         ;time to next event
 
 score          .dw $0000
 
-your_occ       .db $00                 ;0=normal 1=exploding 2=gone
-lives          .dw $0003       ;unused
+your_occ       .db $00                 ;0=normal 1..16=exploding
+;lives         .dw $0003       ;unused
 x              .db $16                 ;x-pos
 y              .db $46                 ;think about it..
 hp             .db $00                 ;hitpoints left
-your_status    .db $00,$00     ;unused
 
 ybullets       .dw 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0       ;10 x (state,x,y)
 ebullets       .dw 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0       ;10 x (state,x,y)
 
+nrenemies      = 32
 enemies                .dw $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000
                .dw $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000
                .dw $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000
                .dw $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000
-               .dw $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000
-; 0011 2233 >> 0=occupation (and %00000011: 0=no enemy 1=normal 2=exploding)
-;              1=frame/ship 2=x 3=y
 
-variables_end:
+               .dw $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000
+               .dw $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000
+               .dw $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000
+               .dw $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000
+
+; %111111 (HP left) 11 (00=no enemy 01=exploding 10=normal 11=moving)
+; %111 (move ptrn) 11111 (ship or explosion frame)  %11111111 (x) %11111111 (y)
+
+
+;---------------------------- enemy data --------------------------------------
+
+spr_enemy01:
+       .db 6,6         ;enemy type one
+       .db %00111100   ;   ████
+       .db %01110000   ;  ███
+       .db %11110000   ; ████
+       .db %11110000   ; ████
+       .db %01110000   ;  ███
+       .db %00111100   ;   ████
+spr_enemy02:
+       .db 6,6         ;enemy type two
+       .db %00111000   ;   ███
+       .db %01100000   ;  ██
+       .db %11111100   ; ██████
+       .db %11111100   ; ██████
+       .db %01100000   ;  ██
+       .db %00111000   ;   ███
+spr_enemy03:
+       .db 6,6         ;enemy type three
+       .db %01111100   ;  █████
+       .db %11110000   ; ████
+       .db %11111000   ; █████
+       .db %11111000   ; █████
+       .db %11110000   ; ████
+       .db %01111100   ;  █████
+spr_enemy04:
+       .db 6,6         ;enemy type four
+       .db %00111000   ;   ███
+       .db %01111100   ;  █████
+       .db %11111000   ; █████
+       .db %11111000   ; █████
+       .db %01111100   ;  █████
+       .db %00111000   ;   ███
+
+enemy01:                               ;HP:1  move:- fire:-
+       .db %00000010,%00000000,%00000000               ;first two enemy bytes
+enemy02:                               ;HP:1  move:1 fire:1.5%
+       .db %00000011,%00100001,%01111111
+enemy03:                               ;HP:2  move:- fire:3%
+       .db %00000110,%00000010,%00001111
+enemy04:                               ;HP:5  move:- fire:6%
+       .db %00010010,%00000011,%00000011
+enemy05:                               ;HP:10 move:- fire:25%
+       .db %00100111,%00000100,%00000011
+
+;---------------------------- level data --------------------------------------
 
-stored_data_end:
+Leveldata:                     ;time,enemyclass,ypos
+       .db $0d,$00,$38                 ;first wave (bottom)
+       .db $00,$00,$40
+       .db $00,$00,$48
+       .db $1e,$00,$10                 ;second wave (top)
+       .db $00,$00,$18
+       .db $00,$00,$20
+       .db $1e,$00,$24                 ;third wave (middle)
+       .db $00,$02,$2c
+       .db $00,$00,$34
+
+       .db $0d,$00,$10                 ;top & bottom
+       .db $00,$00,$4a
+       .db $2a,$01,$2d                 ;middle: moving
+       .db $0c,$02,$2d                 ;        3HP
+       .db $0b,$02,$2d                 ;        3HP
+       .db $09,$00,$27                 ;two 1HP behind him
+       .db $00,$00,$33
+       .db $09,$02,$21                 ;two 3HP behind them
+       .db $00,$02,$39
+       .db $09,$02,$1b                 ;and two 3HP behind them
+       .db $00,$02,$3f
+
+       .db $15,$03,$11                 ;one vertical line of 8HPs
+       .db $00,$03,$19
+       .db $00,$03,$21
+       .db $00,$03,$29
+       .db $00,$03,$31
+       .db $00,$03,$39
+       .db $00,$03,$41
+       .db $00,$03,$49
+
+       .db $0c,$02,$11                 ;one vertical line of 3HPs
+       .db $00,$02,$19
+       .db $00,$02,$21
+       .db $00,$02,$29
+       .db $00,$02,$31
+       .db $00,$02,$39
+       .db $00,$02,$41
+       .db $00,$02,$49
+
+       .db $0c,$00,$11                 ;one vertical line of 1HPs
+       .db $00,$00,$19
+       .db $00,$00,$21
+       .db $00,$00,$29
+       .db $00,$00,$31
+       .db $00,$00,$39
+       .db $00,$00,$41
+       .db $00,$00,$49
+
+
+
+
+
+
+
+       .db $f1,$01,$40
+       .db $10,$00,$30
+       .db $10,$02,$20
+       .db $40,$01,$10
+       .db $01,$00,$44
+       .db $15,$01,$31
+       .db $04,$02,$38
+       .db $05,$00,$40
+       .db $03,$00,$2f
+       .db $04,$00,$3a
+       .db $12,$02,$10
+       .db $10,$03,$18
+       .db $0e,$03,$20
+       .db $0c,$03,$28
+       .db $0a,$02,$30
+       .db $08,$02,$38
+       .db $06,$01,$40
+       .db $04,$00,$48
+       .db $2a,$00,$20
+       .db $ff,$ff,$ff
 
+;----------------------------- end --------------------------------------------
 
        .end
+.end
 
 
 
 
-;NEMESIS'86 by Shiar
+;----------------------------- NEMESIS'86 by Shiar ----------------------------
 
+;----------------------------- version history --------------------------------
 
 ;0.01.717 -- 17.VII.99 -- size 984
 ;
@@ -961,7 +1147,7 @@ stored_data_end:
 ;
 ; 0.1.718 -- 18.VII.99 -- size 907
 ;
-;      * no crash when level restarts for the third time
+;      # no crash when level restarts for the third time
 ;      * exit-procedure updated, unnecessary stuff/keychecks removed
 ;      * alot of unused code removed
 ;      + different types of enemies (just look different)
@@ -978,5 +1164,26 @@ stored_data_end:
 ;      + some enemies can take multiple hits (differs per class)
 ;      + all enemies fire bullets at random
 ;      + if you're hit by bullet/enemy, you'll lose one hitpoint
+;
+; 0.4.720 -- 20.VII.99 -- size 1481
+;
+;      # collision detection fixed and optimized (much faster now!)
+;      + shell-icon added (YAS type)
+;      * code optimizations, some data "compression"
+;      * explosion looks better, and some vars removed/smaller
+;      # enemies are removed if at left side (instead of becoming invisible)
+;      + displays level number before each level begins
+;
+; 0.5.725 -- 25.VII.99 -- size 1778
+;
+;      * waits a sec at level display (in case of accidental keypress)
+;      * moving enemies (move up&down)
+;      # bullets removed correctly so they can be used again later
+;      * first level made
+;      # enemy weaponfire is fired from correct positions
+;      + your ship explodes on impact with ships/bullets
+;      * game over screen will be displayed just *after* your ship's gone
+;      + frame counter onscreen
+;
 
-
+;       + added        - removed       * changed       # bug fixed