Coding techniques - Tyr-dos.

 -= About TYR-DOS =-               
                                          
 Tyr dos... In general, there are many systems, one
however, we poor spektrumists have only one
only tyr-dos.  Well, let's eat something
yes :) And under tyr-dos you can write
(emphasis on the second syllable:) cool weight.
For this you need to use special
subroutines.                           
                                          
 Oh, you know all this? Well, no big deal...
move on, and further for those who need it.
                                          
 All operations are performed through the dot
input #3D13, and register C is written
number of the required subroutine.               
                                          
 #01 - change drive.                    
 Reg.A = drive number (0..3).          
 LD A,1 ; DRIVE B                    
 LD С,1                               
 CALL #3D13 ; *1  RET ; *2                    
                                          
 * At first glance, the combinations are illogical
commands *1 and *2, however this is necessary due to
for the features of tyr-dos.                 
                                          
 #05 - reading sectors.                  
 HL - buffer address.                    
 D - track (odd - top head,     
 even - bottom. 0..159).                
 E - sector (0..15).                    
 B - number of sectors.                   
 LD HL,#4000                           
LD DE,#0100                           
 LD BC, #1В05                           
 CALL #3D13                            
 RET  #06 - recording sectors.                  
 Similar to #05, only recording.        
                                          
 The remaining procedures are not so important. Ruli-
hurry up! Sreccy rulez forever.