write_pixel now allows to set and unset

set - tested
unset - not tested

starfield/main.asm

@@ -41,6 +41,7 @@ main
     call get_screen_address
     ; Video RAM address for those X,Y is now in HL and the bit needed
     ; to be set in that address value is in A
+    ld d, $1
     call write_pixel    ; Uses those values and writes the pixel
 
     pop hl
@@ -96,9 +97,18 @@ write_pixel_loop
     dec b
     jr write_pixel_loop
 write_pixel_do_it
+    ld a, d
+    cp $1
+    jr z, write_pixel_set
+    ld a, (hl)
+    xor c
+    ld (hl), a
+    jr write_pixel_end
+write_pixel_set
     ld a, (hl)
     or c
     ld (hl), a
+write_pixel_end
     pop bc
     ret
 ENDP    

starfield/stargen.py

@@ -15,8 +15,8 @@ f.write("StarRnd\n")
 for x in range(NumStars):
     x = random.randint(0,256 - 1)
     y = random.randint(0,192 - 1)
-    #z = random.randint(0,10)
-    #f.write("\t\tdb %i, %i, %i\n" % (y ,x ,z))
-    f.write("\t\tdb %i, %i\n" % (x ,y))
+    z = random.randint(0,10)
+    #f.write("\t\tdb %i, %i, %i\n" % (x, y, z))
+    f.write("\t\tdb %i, %i\n" % (x, y))
 
 f.close()