aaru-dps/docs
1
0
Fork 0
mirror of https://github.com/aaru-dps/docs.git synced 2025-12-16 19:24:38 +00:00
Code Issues Packages Projects Releases Wiki Activity
Files
712ac67072e96eee1acb8d467461eabce701828a
docs/Commodore/CVT.TXT

138 lines
7.9 KiB
Plaintext
Raw Normal View History

Added information about commodore formats
2015-03-25 02:19:24 +00:00
*** CVT (ConVerT containers)
*** Document revision: 1.3
*** Last updated: Oct 1, 2007
*** Compiler/Editor: Peter Schepers
*** Contributors/sources: Joe Forster/STA
These are sequential representations of GEOS files, both sequential and
VLIR. In order to be transmitted and up/downloaded, they must be converted
to this intermediate format because the file's INFO block (and record block
for a VLIR) must be included. Note that the track/sector references at the
beginning of each sector are not included here, making the block size 254
bytes. Also, any values in track/sector references are invalid, since the
value is sure to change once the file is converted back from CVT to a GEOS
format.
I will not include much of the GEOS file layout details here, as you can
read the GEOS.TXT document to get the information.
With CVT's that contain VLIR files, there are four distinct sections:
signature, info, record and data. CVT's that contain non-VLIR files (i.e.
standard GEOS sequential) do not include the record block.
The first part, which exists in both CVT types, is the signature block.
It contains the complete directory entry and CVT file signature.
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ASCII
----------------------------------------------- ----------------
0000: 83 00 00 44 45 53 4B 20 54 4F 50 A0 A0 A0 A0 A0 <20><><EFBFBD>DESK<53>TOP<4F><50><EFBFBD><EFBFBD><EFBFBD>
0010: A0 A0 A0 00 00 01 04 58 08 13 0D 23 78 00 50 52 <20><><EFBFBD><EFBFBD><EFBFBD>..X...#x<>PR
0020: 47 20 66 6F 72 6D 61 74 74 65 64 20 47 45 4F 53 G<>formatted<65>GEOS
0030: 20 66 69 6C 65 20 56 31 2E 30 00 00 00 00 00 00 <20>file<6C>V1.0<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
00A0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
00B0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
00C0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
00D0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
00E0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
00F0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 .. .. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>..
Byte:$00-1D: Complete directory entry. Note that the first two bytes of
*any* directory entry are never used, and thus are not
incuded here either.
1E-39: File signature. It can contain "PRG formatted..." or "SEQ
formatted...". Here we can check that the CVT is really
what it claims.
3A-FD: Usually $00
What follows the signature block is the complete GEOS file INFO block.
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ASCII
----------------------------------------------- ----------------
00F0: .. .. .. .. .. .. .. .. .. .. .. .. .. .. 03 15 ................
0100: BF FF FF FF 92 49 01 FF FF 01 80 00 1D BF FF DD <20><><EFBFBD><EFBFBD><EFBFBD>I.<2E><>.<2E><>.<2E><><EFBFBD>
0110: A0 00 5D BF FF C1 A0 00 5D A1 C6 55 A0 29 5D A0 <20><>]<5D><><EFBFBD><EFBFBD><EFBFBD>]<5D><>U<EFBFBD>)]<5D>
0120: C9 41 A1 09 41 B9 D6 41 A8 00 41 BF FF C1 80 00 <20>A<EFBFBD>.A<><41>A<EFBFBD><41>A<EFBFBD><41><EFBFBD><EFBFBD><EFBFBD>
0130: 1D 9C 00 15 9C 00 15 80 00 1D 80 00 01 FF FF FF .<2E><>.<2E><>.<2E><>.<2E><>.<2E><><EFBFBD>
0140: 83 04 01 56 19 55 19 75 51 64 65 73 6B 54 6F 70 <20>..V.U.uQdeskTop
0150: 20 41 4D 20 20 56 32 2E 30 00 00 00 00 42 72 69 <20>AM<41><4D>V2.0<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Bri
0160: 61 6E 20 44 6F 75 67 68 65 72 74 79 00 00 00 00 an<61>Dougherty<74><79><EFBFBD><EFBFBD>
0170: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0180: 00 00 00 00 00 4C 2A 5B 4C 59 5D 4C A7 61 4C 3A <20><><EFBFBD><EFBFBD><EFBFBD>L*[LY]L<>aL:
0190: 62 AD 8A 84 D0 01 60 20 7E 23 20 9C 55 73 65 20 b<><62><EFBFBD><EFBFBD>.`<60>~#<23><>Use<73>
01A0: 74 68 65 20 64 65 73 6B 54 6F 70 20 74 6F 20 6D the<68>deskTop<6F>to<74>m
01B0: 61 6E 61 67 65 20 61 6E 64 20 6D 61 6E 69 70 75 anage<67>and<6E>manipu
01C0: 6C 61 74 65 20 79 6F 75 72 20 66 69 6C 65 73 2E late<74>your<75>files.
01D0: 00 03 20 E3 5C 68 85 FB 20 4F 61 20 13 61 20 32 <20>.<2E><>\h<><68><EFBFBD>Oa<4F>.a<>2
01E0: 61 20 F2 5C A9 0C 20 CC 49 A9 2E 85 13 A9 F9 85 a<><61>\<5C>.<2E><>I<EFBFBD>.<2E>.<2E><><EFBFBD>
01F0: 12 A9 2F 85 15 A9 01 85 14 A9 84 85 .. .. .. .. .<2E>/<2F>.<2E>.<2E>.<2E><><EFBFBD>....
The third block is the RECORD block. In the sequential version of the
CVT, this block won't exist. The way to tell if the file is VLIR or
sequential is to look at byte position 23 of the directory entry (from
above, it's value is $01). If it's a $00, the file is sequential, if it's
$01 it's VLIR.
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ASCII
----------------------------------------------- ----------------
01F0: .. .. .. .. .. .. .. .. .. .. .. .. 43 41 0A 0B ............CA..
0200: 0B F4 0A 8C 0B A1 09 70 00 00 00 00 00 00 00 00 .<2E><><EFBFBD>.<2E><>p<EFBFBD><70><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0210: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0220: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0230: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0240: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0250: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0260: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0270: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
0290: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
02A0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
02B0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
02C0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
02D0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
02E0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
02F0: 00 00 00 00 00 00 00 00 00 00 .. .. .. .. .. .. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>......
Note that the RECORD block is modified from the original GEOS entry.
Instead of containing the track and sector references, we now have the
sector count and the size of the last sector in the chain. Looking over the
block above, we get the following usage chart:
Count Size Comment
----- ---- --------------------------------------
43 41 Sector count=67, last sector index=$41
0A 0B Sector count=10, last sector index=$0B
0B F4 Sector count=11, last sector index=$F4
0A 8C Sector count=10, last sector index=$8C
0B A1 Sector count=11, last sector index=$A1
09 70 Sector count=9, last sector index=$70
00 00 No more records.
Two things of interest can be noted from the record block...
1. When a 00/00 is encountered, the record block is done.
2. When a 00/FF is encountered, the record does not exist (see the
GEOS.TXT format for more info on invalid records), but the entry must
still be made in the re-created RECORD block.
From here on we have the actual data, all of the record chains strung
together to form one long file. All of this data must be broken apart to
form the original records that GEOS expects.
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ASCII
----------------------------------------------- ----------------
02F0: .. .. .. .. .. .. .. .. .. .. A9 00 8D EE 04 A4 ..........<2E><><EFBFBD><EFBFBD>.<2E>
0300: FE B9 86 84 30 06 29 0F C9 02 D0 12 A4 70 B9 86 <20><><EFBFBD><EFBFBD>0.).<2E>.<2E>.<2E>p<EFBFBD><70>
0310: 84 30 06 29 0F C9 02 D0 05 A9 07 8D A0 1D 20 1E <20>0.).<2E>.<2E>.<2E>.<2E><>.<2E>.
0320: 23 20 04 1A 8A D0 20 20 12 1A 18 A9 00 6D F4 03 #<23>..<2E><><EFBFBD><EFBFBD>...<2E><>m<EFBFBD>.
0330: 8D F4 03 A9 03 6D F5 03 8D F5 03 20 C5 22 20 7C <20><>.<2E>.m<>.<2E><>.<2E><>"<22>|
0340: 1B 20 04 1A 20 6B 1A A9 08 8D A0 1D B8 50 53 8D .<2E>..<2E>k.<2E>.<2E><>.<2E>PS<50>
0350: EE 04 20 12 1A A2 00 A4 70 20 3F 24 C9 04 B0 3F <20>.<2E>..<2E><><EFBFBD>p<EFBFBD>?$<24>.<2E>?
Reference in New Issue Copy Permalink