*** N64 (64NET container files)
*** Document revision: 1.3
*** Last updated: March 11, 2004
*** Contributors/sources: Markus Mehring
64NET links your C64 and PC together through a special cable, and
provides the C64 access to many image and native files stored on your PC
hard disk. Early versions only provided access to 64NET's custom filetype
"N64", which is explained here, but newer versions also support many of the
common files (LNX, T64, D64, etc).
The following is a dump of an N64 file:
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ASCII
----------------------------------------------- ----------------
00: 43 36 34 01 82 01 08 C4 0C 00 00 00 00 00 00 00 C64????-????????
10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 31 ???????????????1
20: 35 58 58 20 2D 3E 20 36 34 4E 45 54 00 00 00 00 5XX?->?64NET????
30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ????????????????
40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ????????????????
50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ????????????????
60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ????????????????
70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ????????????????
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ????????????????
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ????????????????
A0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ????????????????
B0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ????????????????
C0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ????????????????
D0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ????????????????
E0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ????????????????
F0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 .. .. ??????????????..
Bytes: $00-02: 64NET file signature ("C64")
03: File version ($01)
04: C64 filetype. Valid types are:
$x0=DEL
$x1=SEQ
$x2=PRG
$x3=SEQ
$x4=REL
$x5=DIR (not really implemented)
$x6=VOL (not really implemented)
Bit 0-3: The actual filetype
000 (0) - DEL
001 (1) - SEQ
010 (2) - PRG
011 (3) - USR
100 (4) - REL
Values 5-15 are illegal, but if used will
produce very strange results. The 1541 is
inconsistent in how it treats these bits. Some
routines use all 4 bits, others ignore bit 3,
resulting in values from 0-7.
Bit 4: Not used
Bit 5: Used only during SAVE-@ replacement
Bit 6: Locked flag (Set produces ">" locked files)
Bit 7: Closed flag (Not set produces "*", or "splat"
files)
05-06: Load address of contained file in low/high format. Some
versions do not contain this address, so use the one at
the beginning of the file data.
07-0A: File size (in bytes, low/med1/med2/high format). This
provides access to *very* large files, up to 2
Gigabytes!
0B: Network security level
$00 - None
01 - Visitor
02 - Low
03 - High
04 - Master
0C-1E: Reserved for future use
1F-2E: 16-byte C64 filename in PETASCII, padded with $00
2F: Set to $00
30-FD: Reserved for future use
FE-: Start of file data (including original load address)
Some versions of these files are longer than what the header and file
size total up to. It is safe to ignore this inconsistency and only read the
amount of data dictated by the "file size".
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