I am having a problem when I try to check the busy flag coming from the
LCD display (BUSY_FLAG? subroutine shown below).  It is always busy but
if I remove the busy flag check it runs fine, as long as I use a slow
clock (therefore the display must not be busy).   Any suggestions why
this bit would be remaining high.   the power supply is a 7805 (5+)
being supplied by a 1 amp 12v power supply (120V wall plug in).  I have
a .1uf capacitor from +5 to ground and a .57uf cap from 12V to ground
(for decoupling so I think).  All of this is on a breadboard along with
the PIC 16C84 and Noritake LCD display 4X20 display with selectable 4 or
8 bit transfer.
Thanks.

;October 25, 1999
;


 LIST P=16C84, F=INHX8M, R=DEC
 include <p16c84.inc>
   __CONFIG _CP_OFF & _WDT_OFF & _RC_OSC

DISP_ON   EQU  b'00001101'
CLR_DISP  EQU  b'00000001'
ENTRY_INC  EQU  b'00000110'
MSD   EQU  H'0C'
LSD   EQU  H'0D'
TEMP   EQU  H'0E'
TEMP1   EQU  H'0F'
CHAR   EQU  H'10'
RESET_V   EQU  0
LCD_DELAY_SET  EQU  H'FF'
DD_RAM_ADD  EQU  H'80'
E   EQU  4  ; LCD Enable control line
RW   EQU  3  ; LCD Read/Write control line
RS   EQU  2
;interupt routine varibles
INT_W  EQU  H'11'
INT_S  EQU  H'12'

   org 0
RESET   goto    START
   org 4     ; RESET vector location

Int
 movwf INT_W
 movf STATUS, 0
 movwf  INT_S

START
;pic 16c84 setup for initial state
 movlw b'00000000'
 movwf STATUS   ;Clear Status
 clrf INTCON   ;Initialize INTCON Disable all interupts
; bsf INTCON, 3  ;Makes interupt if RB<7:4> change state
 bsf STATUS,RP0
 movlw b'11000111'
 movwf OPTION_REG  ;Set Option Register
 bcf STATUS,RP0

 clrf PORTA
 clrf PORTB
 bsf STATUS,RP0
 CLRF TRISA
 CLRF TRISB
 bcf STATUS,RP0

;display initialize

 movlw H'20'   ;four bit transfer =h'20' 8 = h'38'
 movwf PORTB
 bsf PORTA,E
 bcf PORTA,E

 movlw DISP_ON

 nop
 nop
 nop
 nop
 nop
 movwf PORTB
 call CMD_SEND

; movlw CLR_DISP
; call CMD_SEND

;send characters
 movlw 'F'
 call CHAR_REC
 movlw 'I'
 call CHAR_REC
 movlw 'N'
 call CHAR_REC
 movlw 'A'
 call CHAR_REC
 movlw 'L'
 call CHAR_REC

 goto $



CMD_SEND
  movwf   CHAR            ; Command to be sent is in W
       call    BUSY_FLAG?      ; Wait for LCD to be ready
        movf    CHAR, 0
       movwf   PORTB         ; Send data to LCD
        bcf     PORTA, RW  ; Set LCD in read mode
        bcf     PORTA, RS ; Set LCD in command mode
        bsf     PORTA, E      ; toggle E for LCD
        bcf     PORTA, E
    ;send lower nibble
 swapf CHAR, 0
 movwf   PORTB
 bsf PORTA, E
 bcf PORTA, E
        RETURN

CHAR_REC
  movwf   CHAR            ; Command to be sent is in W
       call    BUSY_FLAG?      ; Wait for LCD to be ready
        movf    CHAR, 0
       movwf   PORTB         ; Send data to LCD
        bcf     PORTA, RW  ; Set LCD in read mode
        bsf     PORTA, RS ; Set LCD in command mode
        bsf     PORTA, E      ; toggle E for LCD
        bcf     PORTA, E
    ;low nibble transfer
 swapf CHAR,0
 movwf PORTB
 bsf PORTA, E
 bcf PORTA, E
        RETURN
;
BUSY_FLAG?

  bsf     STATUS,RP0       ; Select Register page 1
        movlw   0xF0             ; Set port_B for input
        movwf   TRISB
        bcf     STATUS, RP0      ; Select Register page 0
        bcf     PORTA, RS     ; Set LCD for command mode
        bsf     PORTA, RW    ; Setup to read busy flag
        bsf     PORTA, E      ; Set E high
        bcf     PORTA, E      ; Set E low
        movf    PORTB, 0      ; Read busy flag, DDram address
 andlw 0xF0
 movwf TEMP
 bsf PORTA, E
 bcf PORTA, E
 swapf PORTB, 0
 andlw 0x0F
 iorwf TEMP
 btfsc TEMP,7
; goto BUSY_FLAG?
 nop
 bsf STATUS, RP0
 movlw 0x00
 movwf TRISB
 bcf STATUS, RP0
 RETURN

; movwf
;       movwf   TEMP
;        btfsc   TEMP, 7
;           ; Check busy flag, high=busy
;        goto    BUSY_FLAG?
;        bcf     PORTA, RW
;        bsf     STATUS, RP0      ; Select Register page 1
;        movlw   H'00'
;        movwf   TRISB      ; Set port_B for output
;        bcf     STATUS, RP0      ; Select Register page 0
;        RETURN

 end