//-----------------------------------------------------------
// 
// The file function library for 65CM. ( needs >= v0.070 )
// WARNING: THIS LIB IS ONLY FOR USE ON C64/VIC20
//          ( Eventually for some other CBM series of
//            computers that uses 6502 and the kernel
//            standard. )
//
// Provides an interface for the following functions:
//
// * Open a file in read or write mode. ( SEQ/PRG/USR )
// * Read a pointed block, of given size from an open file.
// * Write a pointed block, of given size to an open file.
// * Close an open file.
// * Load a file ( PRG ) into memory using the files own
//   load-address or into a given address.
// * Save a portion of the memory to a PRG file.
//-----------------------------------------------------------

ASM
          lda #$00 ; disable sysmsgs as default
          jsr lib_setmsg
ENDASM


GOTO lib_skip_filefunc

//-----------------------------------------------------------
// General CBM kernel calls:
//-----------------------------------------------------------

ASM

lib_acptr      = $ffa5
lib_chkin      = $ffc6
lib_chkout     = $ffc9
lib_chrin      = $ffcf
lib_chrout     = $ffd2
lib_ciout      = $ffa8
lib_cint       = $ff81
lib_clall      = $ffe7
lib_close      = $ffc3
lib_clrchn     = $ffcc
lib_getin      = $ffe4
lib_iobase     = $fff3
lib_ioinit     = $ff84
lib_listen     = $ffb1
lib_load       = $ffd5
lib_membot     = $ff9c
lib_memtop     = $ff99
lib_open       = $ffc0
lib_plot       = $fff0
lib_ramtas     = $ff87
lib_rdtim      = $ffde
lib_readst     = $ffb7
lib_restor     = $ff8a
lib_save       = $ffd8
lib_scnkey     = $ff9f
lib_screen     = $ffed
lib_second     = $ff93
lib_setlfs     = $ffba
lib_setmsg     = $ff90
lib_setnam     = $ffbd
lib_settim     = $ffdb
lib_settmo     = $ffa2
lib_stop       = $ffe1
lib_talk       = $ffb4
lib_tksa       = $ff96
lib_udtim      = $ffea
lib_unlsn      = $ffae
lib_untlk      = $ffab
lib_vactor     = $ff8d

ENDASM

//-----------------------------------------------------------
// Function: fopen.
//
//-----------------------------------------------------------

BYTE lib_fopen_filenr
BYTE lib_fopen_devicenr
BYTE lib_fopen_secondnr

WORD lib_fopen_filenameptr


LABEL lib_fopen

ASM
          lda lib_fopen_filenr
          ldx lib_fopen_devicenr
          ldy lib_fopen_secondnr
          jsr lib_setlfs

ENDASM

  LET lib_strlen_strptr GET lib_fopen_filenameptr
  GOSUB lib_strlen

ASM
          lda lib_strlen_return
          ldx lib_fopen_filenameptr
          ldy lib_fopen_filenameptr + 1
          jsr lib_setnam
          jsr lib_open
ENDASM  

SUBEND

//-----------------------------------------------------------
// Function: fclose.
//
//-----------------------------------------------------------

BYTE lib_fclose_filenr

LABEL lib_fclose

ASM
          lda lib_fclose_filenr
          jsr lib_close
ENDASM

SUBEND


//-----------------------------------------------------------
// Function: fwriteblock
//
//-----------------------------------------------------------

BYTE lib_fwriteblock_filenr
WORD lib_fwriteblock_blockptr
WORD lib_fwriteblock_size

LABEL lib_fwriteblock

ASM
          ldx lib_fwriteblock_filenr
          jsr lib_chkout
ENDASM  

  WORD lib_fwriteblock_blkp
  WORD lib_fwriteblock_sz
  BYTE lib_fwriteblock_value
  
  LET lib_fwriteblock_blkp GET lib_fwriteblock_blockptr
  LET lib_fwriteblock_sz GET lib_fwriteblock_size

  WHILE lib_fwriteblock_sz
    PEEK lib_fwriteblock_blkp GIVING lib_fwriteblock_value
ASM
          lda lib_fwriteblock_value
          jsr lib_chrout
ENDASM    

    INCREMENT lib_fwriteblock_blkp
    DECREMENT lib_fwriteblock_sz
  WEND

ASM
          jsr lib_clrchn
ENDASM

SUBEND

//-----------------------------------------------------------
// Function: freadblock
//
//-----------------------------------------------------------

BYTE lib_freadblock_filenr
WORD lib_freadblock_blockptr
WORD lib_freadblock_size

LABEL lib_freadblock

ASM
          ldx lib_freadblock_filenr
          jsr lib_chkin
ENDASM  

  WORD lib_freadblock_blkp
  WORD lib_freadblock_sz
  BYTE lib_freadblock_value
  BYTE lib_freadblock_status
  
  LET lib_freadblock_blkp GET lib_freadblock_blockptr
  LET lib_freadblock_sz GET lib_freadblock_size

  WHILE lib_freadblock_sz
ASM
          jsr lib_chrin
          sta lib_freadblock_value
ENDASM    

    POKE lib_freadblock_blkp WITH lib_freadblock_value
    INCREMENT lib_freadblock_blkp
    DECREMENT lib_freadblock_sz

ASM
          jsr lib_readst
          sta lib_freadblock_status
ENDASM
    IF lib_freadblock_status <> 0 THEN
      GOTO lib_freadblock_break1
    ENDIF

  WEND

  LABEL lib_freadblock_break1

  SUBTRACT lib_freadblock_sz FROM lib_freadblock_size GIVING lib_freadblock_size

ASM
          jsr lib_clrchn
ENDASM

SUBEND

LABEL lib_skip_filefunc