 .PAGE 'NULBUF'
;*********************************
;* NULBUF: SET NULL RECORDS IN   *
;*         ACT-BUF FOR EXTENTION *
;*    VARS:  NR,RS,LX,ACT-BUF    *
;*      IN: NR= LAST RECORD      *
;*          POSITION IN PREVIOUS *
;*          BUFFER.              *
;*     OUT: NR= LAST RECORD      *
;*          POSITION IN BUFFER   *
;*          FOR NEXT NULBUF OR   *
;*          TO SET LSTCHR.       *
;*********************************
;
NULBUF
 JSR SET00 ;SET INDIRECT PTR
 LDY #2
 LDA #0
NB10
 STA (DIRBUF),Y ;CLEAR BUFFER
 INY
 BNE NB10
;
 JSR ADDNR ;ADVANCE NR
NB20
 STA NR,X
 TAY
 LDA #$FF
 STA (DIRBUF),Y ;INIT RECORD W/ CR
 JSR ADDNR
 BCC NB20 ;NOT DONE
;
 BNE NB30
 LDA #0
 STA NR,X
NB30
 RTS
;
; ADD RS & NR, LEAVE IN ACCUM
; C=1: CROSS BUFFER BOUNDARY
;
ADDNR
 LDX LINDX
 LDA NR,X
 SEC
 BEQ AN05
;
 CLC
 ADC RS,X
 BCC AN10
 BNE AN05
 LDA #2
 BIT ER00
 RTS
;
AN05
 ADC #1 ;ADJUST FOR LINK
 SEC
AN10
 RTS
;
;
 .END
