Mibam at 20mhz runs slower than at 4 mhz

[Homerclese]

Hello

I have been playing around with the MIBAM code for quite a while. Sadly, I don't get it. The results that is. Sometimes I will have working code only to come back the next day to find that it morphed into something unrecognizable. I've changed chips, power supplies, re-patched, define bam info... etc....with no change. So I have gone back to square one.

With only 3 outputs running with a 4mhz resonator the fade rate is what I would expect. When I change to a 20 mhz resonator (DEFINE OSC 20 - HS fuse set) the rate slows to a crawl. That is the part I can't understand. Why should the rate slow down with 5 times the clock frequency. I expect to add more outputs which will probably slow things even more. I have code versions that use HSEROUT to output data. That data reads correctly so I know that the clock frequency is right. I see no one else posting this problem so maybe its something about my setup or understanding.

Below is the code. It is basically the example given with the MIBAM code. The J variable does nothing here. I am using 16f628a i/p chips which I believe is a 20 mhz unit (at least that is what the package label said). Any help is greatly appreciated.

 ;----[ MIBAM Setup ]--------------------------------------------------------
 
;____[ For 12F/16F only - Interrupt Context save locations]_________________
wsave       var byte    $20     SYSTEM  ' location for W if in bank0
;wsave       var byte    $70     SYSTEM  ' Alternate save location for W 
                                        ' if using $70, comment out wsave1-3
' --- IF any of these next three lines cause an error ?? -------------------
'       Comment them out to fix the problem ----
' -- The chip being used determines which variables are needed -------------
wsave1      VAR BYTE    $A0     SYSTEM      ' location for W if in bank1
wsave2      VAR BYTE    $120    SYSTEM      ' location for W if in bank2
'wsave3      VAR BYTE    $1A0    SYSTEM      ' location for W if in bank3
'---DO NOT change these-----------------------------------------------------
ssave       VAR BYTE    BANK0   SYSTEM      ' location for STATUS register
psave       VAR BYTE    BANK0   SYSTEM      ' location for PCLATH register 
 
BAM_COUNT CON 3                     ; How many BAM Pins are used?

INCLUDE "MIBAM.pbp"                 ; Mirror Image BAM module
'DEFINE BAM_FREQ 500
'DEFINE OSC 20
DEFINE OSC 4
DEFINE BAM_INFO 1


mybyte var byte
K var byte
W var byte
J var byte
N var byte
RayR   VAR BYTE
RayC   VAR BYTE
RayL   VAR BYTE
RayH   VAR BYTE

ASM
BAM_LIST  macro                     ; Define PIN's to use for BAM
     BAM_PIN (PORTB,1, RayR)         ;   and the associated Duty variables
     BAM_PIN (PORTB,5, RayC)
     BAM_PIN (PORTB,3, RayL)
     ;BAM_PIN (PORTB,6, RayH)
  endm
  BAM_INIT  BAM_LIST                ; Initialize the Pins
ENDASM


Speed       CON 1   ; Smaller = Faster
Brightness  CON 255  ; Max DutyCycle
  
Main:
         
    
  For J = 1 to 8  
    FOR RayR = 0 to Brightness -1          ; Ramp up 1 by 1
        PAUSE Speed
    NEXT RayR
    FOR RayC = 0 to Brightness -1
        PAUSE Speed
    NEXT RayC
    FOR RayL = 0 to Brightness -1
        PAUSE Speed
    NEXT RayL

    FOR RayR = Brightness to 1 STEP -1     ; Ramp down 1 by 1
        PAUSE Speed
    NEXT RayR
    FOR RayC= Brightness to 1 STEP -1
        PAUSE Speed
    NEXT RayC
    FOR RayL = Brightness to 1 STEP -1
        PAUSE Speed
    NEXT RayL
    
  Next J
      
    
GOTO Main

[ScaleRobotics]

The mibam include file reads the osc set in your defines. But if you define your oscillator after the mibam include file, then it assumes your osc is 4 mhz (I think).

Try defining your OSC before your mibam include.