SleepX()

SleepX() is a high resolution replacement for Sleep.

The principle used has an analogy with HiFi were a class B amplifier is used to get us within a neighbourhood of a desired voltage and then uses a class A amplifier to fine tune. The cost of this approach is much less than using only a class A amplifier, which are expensive.

The class B amplifier analogy uses Sleep and the class A amplifier analogy uses the Performance Counter, which has a resolution of 100ns with Windows 10 and later.

The following code has the SleepX() code and a usage example.

This is a typical output.

I have moved Carlo's thread into the members area, in Issues About The PowerBASIC Forum

Should be a better solution, so that the new PB owners won't be aware that we still have access to forum.powerbasic.com.

Anyone who cares to post the final iteration of the "clockwise sort of coordinates" source code, which was recently discussed in the PB forums? I waited too long to store a local copy.

Thanks.

I'm starting to work on a pac-man maze.  I have a long road ahead of me with this challenge.   I'm going with a technique I read up on using tiles that are setup as a grid that allows you to draw the maze dynamically.  Each tile is stored in a 2D array.  The maze is setup 28 across and 31 tiles down.  The array elements are structures that allow you to include properties or attributes about the tile and can be used for game flow logic and drawing updates.   I'm curious to know if anyone else in PB land has done any work in this area?  TIA. 

A picture of what I have so far... (obviously more work to be done )
   

How could I detect and handle for example a webcam with Power Basic?
I have no experience with this topic.

When I write:

CHDR "D:\Test_with_Files"

A = "Original.exe"
B = "Original_Copy.exe"
Filecopy A, B

A is existing on the harddrive but File B is not created. Why is that?

Have waded back thru the previous forum posts but at a loss to get an answer.
Sorry if it's been asked before but all I need is the numerical string for the Current UTC timestamp.
How?
Thanks.

Hello everyone, 
I developed a method to compress short texts by reducing 8-bit characters to 7-bit. While the compression ratio is low for large files, it efficiently reduces small strings. 

Key Steps: 

1. Normalization: The input text is restricted to 7-bit ASCII (32–127).
   
2. Offset Adjustment: Each character is decremented by 32 to fit within 0–95. 
   
3. Compression: 
   For every 8 bytes, extract bits 0–6 (discarding bit 7).Pack these 7-bit segments into 7 bytes, using all 8 bits per byte. 
   
4. Remaining Bytes: If the text length isn’t a multiple of 8, the last 1–7 bytes are copied uncompressed.
   
5. Decompression: 
   Reverse the process: Expand 7-bit segments to 8 bits, then increment by 32. 
   

Source code moved from PB DOS over here, in reply to @Andy Dee:

'DECLARE not needed if FUNCTION source is before the CALL
'here the CALL is in PBMAIN
'I call it bottom up because PBMAIN is last and flow goes up
'
'Pretty sure PUSHes and POPs not needed in FUNCTION
'They will be needed to use "inside" code in-line with BASIC
'
'Used PBCC v6 to test. I no longer have PBDOS available.
function Tage_im_Februar(byval iJahr as integer) as integer
  local FebruarTage as integer
  ! push ax
  ! mov FebruarTage, 28&  'not a leap year, pre-set to 28
  ! mov ax, 1582%
  ! cmp ax, iJahr
  ! jge Julian
  ! mov ax, 3%
  ! and ax, iJahr    'conditionally equivalent MOD 4
  ! jz MOD100        '0 is possible leap year
  ! jmp Done
  MOD100:
  ! push bx          'for divisor
  ! push dx          'for high part of dividend, remainder (MOD)
  ! xor dx, dx
  ! mov ax, iJahr
  ! mov bx, 100%
  ! div bx
  ! cmp dx, 0%    'does MOD 100 = 0 ?
  ! pop dx
  ! pop bx
  ! jz MOD400        '0 is possibly not a leap year
  ! jmp Is29Days      'non 0 is a leap year
  MOD400:
  ! and ax, 3%    'EAX has Year\100, so conditionally equivalent MOD 400
  ! jnz Done
  Julian:
  ! mov ax, 3%
  ! and ax, iJahr
  ! jnz Done
  Is29Days:
  ! mov FebruarTage, 29%
  Done:
  ! pop ax
  function = FebruarTage
end function
function pbmain () as long 'put only to demonstrate Tage_im_Februar
  local iJahr as integer
  iJahr = 2000
  print Tage_im_Februar(iJahr); " 2000, divisible by 400, is leap"
  iJahr = 2100
  print Tage_im_Februar(iJahr); " 2100, divisible by 100 not 400, not leap"
  iJahr = 2104
  print Tage_im_Februar(iJahr); " 2104, divisible by 4 not 100, is leap"
  iJahr = 2103
  print Tage_im_Februar(iJahr); " 2103, not divide 4, not leap
  print "julian, did not check rule for prior to Gregorian myself"
  iJahr = 1204
  print Tage_im_Februar(iJahr); " 1204, divisible by 4, is leap
  iJahr = 1201
  print Tage_im_Februar(iJahr)  " 1201, not divisible by 4, not leap
  waitkey$
end function