How to learn assembely?

[amindzo]

Hi, i have done alot of project in picbasic but i found that it has some problem,for example i found that in conditional instruction (if... then..),intrupt doesn't work.
i wrote a program to read the keyboard(4*4) with conditonal instruction but RB0 interrupt didin't work but when i used RB0 interrupt in other programs without conditional instructions it worked ver well.
so i think the best langauge is assembly.it's faster. conversion of the C or Pic basic to assembely or hex file is not optimal. in some project speed is very important so the best choice is assembly.

[mvs_sarma]

Hi, i have done alot of project in picbasic but i found that it has some problem,for example i found that in conditional instruction (if... then..),intrupt doesn't work.
i wrote a program to read the keyboard(4*4) with conditonal instruction but RB0 interrupt didin't work but when i used RB0 interrupt in other programs without conditional instructions it worked ver well.
so i think the best langauge is assembly.it's faster. conversion of the C or Pic basic to assembely or hex file is not optimal. in some project speed is very important so the best choice is assembly.

I admit that I am no expert in these languages, but , to my little knowledge, any program written in HLL has to be compiled and you know what happens if you compile such a file. it looks into a pre wriitten code and uses a judicious part of the code available there. Perhpas over a period these HLLs are revised to cover difficiencies. --that is the reason you find that a particular suppliers Basic otr 'C' is better than others etc,

thus ifeel there is nothing wrong, ifct it is better to write(be able to write) in assy language. aprogram written by a skilled writer in assy is much better than a compiled Basic or C-- of course my personal feeling.

[mister_e]

Whatever the language you're using, just get the job done and that's it.

mvs_sarma, you have many good points which i agree with. Writing in assembler , even if looks monster and painfull, have it's advantages. I wish i could go back and learn Assembler first.. bah too late

At least, someone's beginning programming in assembler will probably learn better how to use, set-up, the internal PIC ressources... as there's nothing already done. Let's say ADCIN, HSEROUT etc etc. Better hardware understanding.

Also it force the programmer to use it's brain a little bit much. Let's say someone want to compute a multicondition IF THEN ELSE like

IF (ByteA<300) AND (ByteC>=ByteA) AND (ByteC+ByteD<127) then...

Obviously, knowing how many assembler instruction you have, and what's available, he will spend more time to write the code than with any compiler.

But both will produce the same result, one will be faster to write.

Better because it's written in assembler? no, 'cause both work. Maybe one may need more codespace... but less time to write.

I will stop here and stick on my opinion. Nothing is better, if the final code/product works as expected and bug-free.

Sure i don't reject any language advantages. You just have to trust the compiler you're using.

[keithdoxey]

IF (ByteA<300) AND (ByteC>=ByteA) AND (ByteC+ByteD<127) then...

If ByteA really is a byte then the first condition will always be true

Not having a dig Steve, just posting something to make the "you have not posted for a while" message go away. LOL

[T.Jackson]

IF (ByteA<300) AND (ByteC>=ByteA) AND (ByteC+ByteD<127) then...

This is an extremely inefficient, code space consuming argument.<hr/>
Here's a better approach that will use much less code space and probably be a lot faster too.<hr/>

IF ByteA<300 THEN
   IF ByteC>=ByteA THEN
      IF (ByteC+ByteD<127 THEN
      'do something
      ENDIF
   ENDIF
ENDIF

Willing to bet this is about 20-30 bytes shorter.
<br/>

[T.Jackson]

Using Select Case is by far the very best methodology for implementing well structured decision making procedures. I'm a little uncertain as to just how advantageous it can be in PBP, but in Visual Basic, it's a god sent!

Consider the following:

SELECT CASE UserInput

   CASE 1
           GOSUB Temperature
           LOW LED
           
   CASE 2
           GOSUB LightLevel
           HIGH LED
END SELECT

<hr/>
Much easier to read and much faster. Select Case is a much more efficient, IF statement equivalent. However they can at times be a bit quirky for certain things.
<br/>

[T.Jackson]

Now consider the following:

      Select Case JoystickDat.dwXpos
             '//
             'right?
             '//
             Case Is > 50000
                  If Boat_ID <> 2 Then                               'sound on condition
                     If Master_SND_EN Then
                        If AllowRowSND = 0 And Jumping = False And Allow_SND_Effects = True Then
                           SND = sndPlaySound(App.Path & "\Water.wav", CSNDaSync)
                           AllowRowSND = 1                           'sound effect once only
                        End If                                       '
                     End If
                     '//                                             '
                     Rowing_Forward = True                           'set flag
                     Rowing_Backward = False                         'set flag
                     '//                                             '
                     If Jumping Then                                 '
                        'lmitied control when airborne               '
                        PlayerX = PlayerX + (PlayerX < 375) * -1     'inc 1 pixel
                        Boat_ID = 4                                 'ors out img
                     Else                                            '
                     'maintain screen limitations and inc boat forward
                        PlayerX = PlayerX + (PlayerX < 250) * -(1 + Row_Speed)
                        Row_Speed = Row_Speed + (Row_Speed < 20) * -2
                        Boat_ID = 2                                 'row img
                     End If
                     '//                                             '
                  Else                                               '
                     '//                                             '
                     If Jumping Then                                 '
                        Boat_ID = 4                                 'ors in img
                     Else                                            '
                        Boat_ID = 1                                 'ors out img
                     End If                                          '
                  End If
             '//
             'joystick center?
             '//
             Case Is > 500 And JoystickDat.dwXpos < 50000
                  If Jumping = False Then
                     If Master_SND_EN Then
                        If Row_Speed = 5 And Allow_SND_Effects = True Then
                           SND = sndPlaySound(App.Path & "\Water B.wav", CSNDaSync)
                        End If
                     End If
                  '//
                     Row_Speed = Row_Speed + (Row_Speed > 0) * 1     'grad dec speed                          '
                  '//                                                '
                     If Rowing_Forward Then                          '
                        Boat_ID = Boat_ID + (Boat_ID = 2) * 1     'reset image
                        Rowing_Forward = False                       'flag
                        AllowRowSND = 0                              'en sound for next time
                     Else                                            '
                        Boat_ID = Boat_ID + (Boat_ID = 0) * -1    'reset image
                        AllowRowSND = 0                              'en sound
                        Rowing_Backward = False                      'flag
                     End If
                  End If
             '//
             'left?
             '//
             Case Is < 500
                  If Boat_ID <> 0 Then                               'sound on condition
                     If Master_SND_EN Then
                        If AllowRowSND = 0 And Jumping = False And Allow_SND_Effects = True Then
                           SND = sndPlaySound(App.Path & "\Water.wav", CSNDaSync)
                           AllowRowSND = 1                           'en sound
                        End If                                       '
                     End If
                     '//
                     Rowing_Backward = True                          'set action flag
                     Rowing_Forward = False                          'set flag
                     '//                                             '
                     If Jumping = False Then                         '
                        PlayerX = PlayerX + (PlayerX > 50) * 10      'inc 10 pixel backward
                        Row_Speed = Row_Speed + (Row_Speed > 0) * 2  'grad dec speed                          '
                        Boat_ID = 0                                  'row back img
                     Else
                        'lmitied control when airborne               '
                        PlayerX = PlayerX + (PlayerX > 50) * 1       '
                        Boat_ID = 4                                  'ors out
                     End If
                     '//
                  Else
                     '//
                     If Jumping Then
                        Boat_ID = 4                                  'ors out img
                     Else                                            '
                        Boat_ID = 1                                  'ors in img
                     End If
                  End If
      End Select
      '//---//
      'Y-axis
      '//---//
      Select Case JoystickDat.dwYpos
             '//
             'up?
             '//
             Case Is < 500
                  If Jumping Then
                     PlayerY = PlayerY + (PlayerY > 375) * 2         'inc 2
                  Else
                     PlayerY = PlayerY + (PlayerY > 375) * 5         'inc 5
                  End If
             '//
             'down
             '//
             Case Is > 50000
                  If Jumping Then
                     PlayerY = PlayerY + (PlayerY < 475) * -2        'inc 2 pixel
                  Else                                               '
                     PlayerY = PlayerY + (PlayerY < 475) * -5        'inc 5
                  End If
      End Select

<hr/>
Now, while Select Case itself isn't used for all decision making, its main role here is for structure. It greatly improves clarity and organization. It clearly separates the algorithm into much more easily manageable parts. It's perhaps not quite that obvious in this example because there's really on 2 parts in each Select Case.
<br/>

[mister_e]

<table><tr><td></td><td>It wasn't meant to be a 'how to create efficient code' tutorial or contest, but just an example.

Who i'm i anyway ?</td></tr></table>

FYI, in PBP Select Case will be a little less code efficient (talking about code size) than multiple IF-THEN-ELSE... as with ALL other language anyway. Select Case is just easier to read, modify, implement. Save your finger nails...

We are really far of the original question...