Coder`z guide - This section is so named because it will talk about things that will be useful to people who code.

                    
                    
                    
                    
                    
               + - - = = Coders` guide. = = - - +               
(с) Lynx/>                                            
                                                                
    Этот  раздел  назван  так  потому, что в нем будет рассказы-
ваться  о  вешaх,  которые  будут  полезны людям, которые кодят,
именно кодят, a не прогрaмят!                                   
    O различиях между кодингом и программингом я говорить не бу-
ду, здесь и так все ясно. B коде важна скорость, a в nporpammuh-
ге -result...                                               
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   Because  this section also appeared in the newspaper for the first time, then I took
the easiest topic for discussion, especially since the story is about
code need begin, and not snatch something from somewhere ;) and
start pushing hard, it will rule!                        
  So, I took the topic - open frame screen out... This is the so-called
permanent, fastscreen ejection that occurs in 1 (one)
frame... Once upon a time, someone was grumbling that this was not possible, and
maximum speed transfer data - 12.5 cycles per byte, and
This was implemented using a stack:                           
            POP  HL                                            
            LD (xxxx),HL                                     
  At the same time, the stack was in the screen image somewhere in memory.
It's slow and suitable for all sorts of scrolling and miscarriages
sprites on the screen and for similar things. This is the simplest
method fast memory access. However
method this exists, and everyone knows it, and it consists in
straightplacing bytes on the stack. This is incredibly easy to implement:   
            LD HL,xxxx                                       
            PUSH HL                                            
  That is, 10.5  clock cycles per byte.                                     
 In this case, the stack is on the screen, and the HL register is constantly being filled with
xia by two bytes from the screen. That's the whole method. And yet, I remember
here they once talked about that this method is small, where can it be used
Not however, with you can use it to simply throw it away
screen on screen ;) and implementation 3-сlor`a before organization
Scroll`a...                                                     
  At the same time, if you have Pentagon int, then there is still time
on playing music, preferably compiled in pro-tpakepe
(there the player takes up only 4000 cycles), as well as
Painting the screen a uniform color.                           
  For example, I give a procedure for generating an FMA procedure by
this method, as well as screen output.                           
                                                                
;FMA                                                            
;(c)Lynx                                                        
;----------------------------------------------------------------             
;Procedure generator;------------------------------------------------------         
GENER   LD      HL,SCR+#17FF                                    
        LD      DE,#C189                                        
        LD      BC,3072                                         
        LD      А,#31;LD SP,#5800                               
        LD      (DE),А                                          
        INC     DE                                              
        XOR     А LD      (DE),А                                          
        INC     DE                                              
        LD      А,#58                                           
        LD      (DE),А                                          
        INC     DE                                              
        XOR     А                                               
        LD      (DE),А                                          
        INC     DE                                              
G_1     LD      А,#21                                           
        LD      (DE),А                                          
        INC     DE                                              
        DEC     HL                                              
        LD      А,(HL)                                          
        LD      (DE),А                                          
        INC     DE                                              
        INC     HLLD      А,(HL)                                          
        LD      (DE),А                                          
        DEC     HL                                              
        DEC     HL                                              
        INC     DE                                              
        LD      А,#E5                                           
        LD      (DE),А                                          
        INC     DE                                              
        DEC    BC                                              
        LD      А,B                                             
        OR      C                                               
        JR      NZ,G_1                                          
        LD      А,#C3                                           
        LD      (DE),А                                          
        INC     DE                                              
        LD      HL,МАК_2                                        
        LD      А,L                                             
        LD      (DE),А                                          
        INC     DE                                              
        LD      А,Н                                             
        LD      (DE),А                                          
                                                                
        RET                                                     
MKCOL   LD      DE,#C000                                        
        LD      А,#31                                           
        LD      (DE),А                                          
        INC     DE                                              
        XOR     А                                               
        LD      (DE),А                                          
        INC     DE                                              
        LD      А,#5B                                           
        LD      (DE),А                                          
        INC     DE                                              
        LDА,#21                                           
        LD      (DE),А                                          
        INC     DE                                              
COLOR   LD      А,3                                             
        LD      (DE),А                                          
        INC     DE                                              
        LD      (DE),А                                          
        INC     DE                                              
        LD      BC,#183                                         
ZUKER   LD      А,#E5                                           
        LD      (DE),А                                          
        DEC     BC                                              
        INC     DE                                              
        LD      А,B                                             
        OR      C                                               
        JR      NZ,ZUKER                                        
        RET                                                     
;Viewing caller                                                 
                                                                
MAKER   LD      (МК+1),SP                                       
МАК                                                             
        DI                                                      
        JP      #C000                                           
МАК_2   EI                                                      
МК      LD      SP,0                                            
        RET  In this case, the MAKER procedure should be called.                   
  Now I would like to say a few words about the implementation
3-color`a. The screen, as you noticed, is drawn from bottom to top,
because it's still a stack. U, therefore there is such a place on
screen, where the beam and the drawing itself meet. So, above
this place the drawn image will not be visible! Trace-
Therefore, this method is not acceptable! No, and there is a way out, you need
but generate the procedure thirds of the screen back to front! U in re-
al-time to rearrange the stack after drawing the screen.             
   Well, try it yourself! Bye.