Help needed for PC-controlled Wireless Notice Board on USART

Hey guys,
I'm doing a project on wireless notice board, and my codes are in assembly language
1. The wireless module is zigbee, and it's from pc to PIC,
2. The display is dot-matrix and data will be taken from EEPROM to be displayed
3. Only one way communication using USART from Zigbee to PIC6f628A
4. PIC will receive new data whenever available from ZigBee and store in EEPROM
5. The PC will be sending data through a ZigBee transmitter to the receiver.

So, currently I've got my display unit to work and everything, and can display 128 characters. All of which is pre-loaded into the EEPROM.
I'm having trouble with the communications part. How do I use USART to receive a data string and store into EEPROM one byte at a time? Plus I don't want to do the polling method.

Attached is the codings that i've written.
1. The original code is working fine and i need to embed the USART part into it
2. The Usart RC file is the one I've written for serial communication with ZigBee that needs to be embedded.

The code should work as: Displaying out data from EEPROM and when new data is received, it will take it and store into EEPROM and then start displaying all over again. Please help. Thanks

Here is the Usart part:

org     0x04        ;interrupt service vector
    movwf    W_Save
    movf     STATUS,W
    clrf     STATUS
    movwf    STATUS_Save
    movf     PCLATH,W
    movwf     PCLATH_Save

    movlw    0x00
    movwf    eefile
    
goto    RCINT

    movf    PCLATH_Save
    movwf    PCLATH,W
    movf    STATUS_Save
    movwf    STATUS,W
    movf    W_Save
    retfie

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

    movlw    0xC0    ;setting up the interrupt, goes into the main part
    movwf    INTCON
    movlw    0x00
    movwf    PIR1

    movlw    0x68
    bsf    STATUS,RP0
    movwf    SPBRG
    movlw    0xA0
    movwf    PIE1
    bcf    TXSTA,BRGH
    bcf    TXSTA,SYNC
    bcf    STATUS.RP0

    bsf    RCSTA,SPEN
    bsf    RCSTA,CREN
    bcf    RCSTA,RX9

    bsf    STATUS,RP0
    movlw    0x02
    movwf    TRISB        ;RB1 is the rx pin

    end

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

RCINT    movf    RCREG,W
    bsf    STATUS,RP0
    movwf    EEDATA
    bcf    STATUS,RP0

    movf    eefile
    bsf    STATUS,RP0
    movwf    EEADR
    bcf    STATUS,RP0
    call    write
    
    incf    eefile,F
    movf    eefile
    bsf    STATUS,RP0
    movwf    EEDATA
    movlw    0x7F
    movwf    EEADR
    bcf    STATUS,RP0
    call     write

    bcf    PIR1,RCIF
    retfie    

write    bsf    STATUS,RP0    ;select bank1    ;writes it to EEPROM
    bsf    EECON1,WREN    ;enable write
    bcf    INTCON,GIE        
    movlw    0X55        ;unlock codes
    movwf    EECON2
    movlw    0xAA
    movwf    EECON2
    bsf    EECON1,WR    ;write begins
    bsf    INTCON.GIE
    bcf    STATUS,RP0    ;select bank0        
writeA    btfss    PIR1,EEIF    ;wait for write to complete
    goto    writeA
    bcf    PIR1,EEIF
    bsf    STATUS,RP0    ;select bank1
    bcf    EECON1,WREN    ;disable other writes
    bcf    STATUS,RP0    ;select bank0                    
    retlw    00