Page Comparison

OZ GN_Crc - RST 20H, DEFW $7C09

IN:
    A = CRC_FILE (1)
    HL = pointer to file buffer (local memory) 
    BC = buffer size
    DE = 0, Initialize CRC-32 with FFFFFFFFh
    DE > 0, (local) pointer to initial 4-byte CRC-32
    IX = file handle of open file (using GN_Opf)

OUT, if call successful:
    Fc = 0,
    DEBC = CRC-32

OUT, if call failed:
    Fc = 1,
	A = RC_BAD ($04) - bad argument
    A = RC_xxx (file & handle related errors)

Registers changed after return:
    ......HL/IXIY same
    AFBCDE../.... different

OZ GN_Crc - RST 20H, DEFW $7C09

IN:
    A = CRC_PARTFILEBYTE (2)
    HL = max bytes to read for this partial scan, or -1 for rest of file
    DEBC = Initial CRC-32 or input from result of previous partial CRC-32 scan
    IX = file handle of open file (using GN_Opf)

OUT, if call successful:
    Fc = 0
    DEBC = partial CRC-32 result (DE = high-word, BC = low-word), to be used for next scan iteration 

    Fc = 1, A _RC_Eof
    DEBC = final CRC-32 result (DE = high-word, BC = low-word) 

OUT, if call failed:
    Fc = 1,
	A = RC_BAD ($04) - bad argument
    A = RC_xxx (file & handle related errors)

Registers changed after return:
    ......HL/IXIY same
    AFBCDE../.... different

OZ GN_Crc - RST 20H, DEFW $7C09

IN:
    A = CRC_PARTFILEBUF (3)
    HL = pointer to file buffer (local memory), 
    BC = buffer size 
    DE = 0, Initialize CRC-32 with FFFFFFFFh
    DE > 0, (local) pointer to 4-byte CRC-32 (initial CRC-32 or input from result of previous partial scan)
    IX = file handle of open file (using GN_Opf)

OUT, if call successful:
    Fc = 0
    DEBC = partial CRC-32 result (DE = high-word, BC = low-word), to be used for next scan iteration

    Fc = 1, A _RC_Eof
    DEBC = final CRC-32 result (DE = high-word, BC = low-word) 

OUT, if call failed:
    Fc = 1,
	A = RC_BAD ($04) - bad argument
    A = RC_xxx (file & handle related errors)

Registers changed after return:
    ......HL/IXIY same
    AFBCDE../.... different

OZ GN_Crc - RST 20H, DEFW $7C09

IN:
    A = CRC_EPFILE (4)
    BHL = pointer to file entry
    DE = 0, Initialize CRC-32 with FFFFFFFFh
    DE > 0, (local) pointer to initial 4-byte CRC-32

OUT, if call successful:
    Fc = 0,
    DEBC = CRC-32
OUT, if call failed:
    Fc = 1,
	A = RC_BAD ($04) - bad argument
    A = RC_xxx (file card related errors)

 Registers changed after return:
    ......HL/IXIY same
    AFBCDE../.... different

OZ GN_Crc - RST 20H, DEFW $7C09

IN:
    A = CRC_PARTEPFILE (5)

    Initial call:
    BHL = pointer to File Entry
    DE = max. size of bytes to read per partial scan
    IX = pointer to local memory (allocated in application/popdown workspace, 12 bytes):
    (IX + 0,23) : 24bit offset: toInitial fileCRC-32 entryor imageinput (setfrom toresult 0of onprevious inital call), low-byte, high-byte orderpartial CRC-32 scan
     (IX + 34,46)   : max. bytes to read per partial scanReserved for 24bit file pointer (initialized after first call)
    (IX + 57,89)   : InitialReserved CRC-32for orsize inputof fromfile resultentry of(initialized previousafter partial CRC-32 scanfirst call)
  OUT, if call(IX successful:
    Fc = 0
    (IX + 0,2) : 24bit offset updated for next partial scan
    (IX + 5,8) : partial CRC-32 result, low-byte, high-byte order+ 10,11) : Reserved for max. bytes to read per partial scan

    Subsequent calls:
    BHL = 0 (this is returned automatically after initial call to this method)
    IX Fc = 1pointer to updated local memory Aof = RC_Eof (complete file scanned)CRC-32 variables (12 bytes):

 OUT:
    (IXBHL += 50,8) always
:
final CRC-32 result, low-byte, high-byte order

OUT, if call failed:
    Fc = 1,
	A = RC_BAD ($04) - bad argument
    A = RC_xxx (file card related errors)

 Registers changed after return:
    ..BCDEHL/IXIY same
    AF....../.... different