Using Octal in PE6

#1
Morning folks,

Just a very quick question - does the PICAXE Editor support the Octal numbering system? Just personal preference, given that it's base-8... useful for an 8-bit microcontroller... Just can't find reference to it in the documentation

Cheers!
 

hippy

Technical Support
Staff member
#2
PE6 doesn't support octal numbering natively but if you really wanted to include octal numbers in your program you could handle numbers up to 37777 using macros -
Code:
#Macro SetOctal(var,n)
  w11 = n
  Gosub Do_SetOctal
  var = w12
#EndMacro

#Macro SerOct(n)
  w11 = n
  Gosub Do_SerOctal
#EndMacro

Test:
  SetOctal(w2,377)
  SerTxd( "Octal 377 = ", #w2, TAB, "Octal = " )
  SerOct( w2 )
  SerTxd( CR, LF )
  End

Do_SetOctal:
  w12 = 0
  w13 = 1
  Do While w11 > 0
    w12 = w11 // 10 & 7 * w13 + w12
    w11 = w11 /  10
    w13 = w13 * 8
  Loop
  Return

Do_SerOctal:
  w13 = $8000
  Do While w13 > w11 And w13 > 1
    w13 = w13 / 8
  Loop
  Do
    w12 = w11 / w13 & 7 : SerTxd( #w12)
    w13 = w13 / 8
  Loop Until w13 = 0
  Return
  Return
 
Last edited:

Technical

Technical Support
Staff member
#5
If you turn off the preprocessor you can unofficially use this. Octal has been in the compiler as a hidden test mode for 20 years, but can't remember anyone ever asking before!

Code:
do
    let b1 = '\17'
loop
 

Aries

New Member
#6
I started my computing career with the Univac 1108, which had a 36-bit word. It used octal for its "internal" numbers, which made sense, because a word held 12 octal digits. (It also used the Fieldata character set - 6-bits, so 6 to the word). Anything using 8, 16, or 32 bit "words" is going to prefer Hex rather than octal, because octal digits do not fit neatly into the power-of-2 word sizes. Indeed, when Univac included the ASCII charater set, it used 9 bits rather than 8, so that each character fitted into a quarter word. So ... if you have an 8-bit microprocessor, Hex makes more sense than octal, because octal is always going to have a "short digit" at the front.
 
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