i've checked so far 51 PC Engine CD, that's close to 10% from all there is, and i thought, this might be a good moment to summarize this information, since i guess 10% can be sufficient, to outline main characteristics of the whole set, and if something is wrong, it's still not to hard to go back at this point and redo and correct mistakes.
layout:
[s]only rule, i think, is that cd starts with an audio track. so far 2nd track always was data, but in necstasy, i think, i saw a CDs where this is not true either but still audio would always preceed data.[/s] this 1st track is the same most of the time or often contains same audio data with a different offset, but there are quite a lot exceptions.
because of this audio track, the one, that preceeds data, it's a bit more complicated to dump PCE CDs.
tracks:
when offset is corrected, audio starts most of the time with an hex offset 0x0 from LBA: 1st track, and 0x4000: rest. except some rare exceptions audio tracks don't have any empty sectors at the end. only padding zeroes to fill till the end of last sector.
data tracks are mode 1 always. and except only a handful cases, where post-gap for last data track was messed up, there wasn't anything unusual at all.
subcode:
i did 3 checks on subcode (PMA only):
r-w channels!=0x00
q-mode=2 and q-data!=0x00
index>1
nothing. it's only some random bit's set in one or more channels now and then. and most cancels out on several rereads. i don't think deliberately altered data can look that way. it's nothing like NeoGeo subcode, where you can clearly see large blocks of similar changes follow each other. though there were some PCE releases post y2k, i think, maybe those are different.
gaps:
this is, what makes this system difficult to dump currently, partly because of the way how EAC calculates them.
theory (ECMA-130):
20 Track structure of the Information Area
The Information area shall contain Information Tracks in
- the Lead-in Area;
- the User Data Area;
- the Lead-out Area.
The Lead-in Area shall contain only one Information Track called Lead-in Track. The Lead-out Area contains only
one Information Track called Lead-out Track.
The user data shall be recorded in the Information Tracks in the User Data Area. All Information Tracks containing
digital data shall be structured in Sectors.
For the purpose of linking Information Tracks in the Information Area, these tracks may have:
a) Pause : A part of an Information Track on which only control information but no user data is recorded.
b) Pre-gap : A first part of a Digital Data Track not containing user data and encoded as a Pause. It is divided
into two intervals:
- first interval: at least 75 Sections (at least 1 s) coded as the preceding track, i.e. the Control field
(see 22.3.1) of the q-channel (see 22.3) and, in case of a preceding Digital Data Track, the setting
of the Sector Mode byte are identical with those of the previous Information Track;
- second interval: at least 150 Sections (at least 2 s) in which the Control field of the q-channel and
the setting of the Sector Mode byte are identical with those of the part of the track where user
data is recorded. In this interval of the Pre-gap the data is structured in Sectors.
c) Post-gap : A last part of a Digital Data Track, not containing user data, and structured in Sectors. It has the
length of at least 150 Sections (at least 2 s). The setting of the Control field of the q-channel and
the setting of the Sector Mode byte are identical with those of the part of the track where the user
data is recorded.
20.1 Lead-in Area
The Lead-in Track is either a Digital Data Track or an Audio Track. If it is a Digital Data Track, it shall be
structured in Sectors and end with a Post-gap. If it is an Audio Track, it shall be according to IEC 908.
20.2 User Data Area
The Information Tracks in the User Data Area shall be either Digital Data Tracks only or Digital Data Tracks and
Audio Tracks. The following rules apply to the tracks in the User Data Area:
- If the first Information Track is a Digital Data Track, it shall start with a Pause of 150 Sections (2 s) and shall
be coded as the second interval of a Pre-gap.
- A Digital Data Track, not being the first track in the User Data Area, shall begin with a Pre-gap if the
preceding track is a Digital Data Track with a different Sector mode or if it is an Audio Track.
- A Digital Data Track shall end with a Post-gap if the following track is an Audio Track. This rule applies also
to the last Digital Data Track in the User Data Area, which is followed by the Lead-out Track.
20.3 Lead-out Area
The Lead-out Track is either a Digital Data Track or an Audio Track. If it is a Digital Data Track, it shall be
structured in Sectors, without Pre-gap. If the Lead-out Track is an Audio Track, it shall be according to IEC 908.reality:
Serial |Ring |Gap Layout |Empty M1 sectors in |Audio Offset |Notes
| |A->D;D->A;A->A |D->A Transition Area |track=1st; |
| | |track<last;track=last |track>1st |
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
KOCD3003 HRKO30721-1FAAT 3.00;2.00;0.00 0;0 0;0..44628 last sector for the last data track = audio silence (0x00): gets junked with offset
KSCD2003 TTTTFKS31008-1 SAC1 3.00;2.00;0.00 338;191 4000;4000
MWCD2003 FFTTTMW30214-1 S2U2 3.00;2.00;0.00 150 0;4000
NAPR1013 TFLTFNA10131211-6 QBZ2 3.00;2.00;0.00 150;3 0;4000
NAPR1022 TFTTFNA10221105-9 RAG4 3.00;2.00;0.00 150;3 0;4000 Track 08 is dummy
NAPR1024 LLLFTNA10240828-4 R8Y4 3.00;2.00;0.00 246;99 0;4000
NAPR1026 TLFTT NA260301-1 U3R7 3.00;2.00;0.00 150;3 0;4800/5000
NAPR1029 TFFTTNA10290629-4 S6C3 3.00;2.00;0.00 150;3 0;4000
NAPR1034 FTTLLNA10340224-1 T3V3 3.00;2.00;0.00 150;3 0;4000
NAPR1035 LFLFT NA350601-1 U6W2 3.00;2.00;0.00 150;3 0;4800
NAPR1036 TFFFT NA360601-1 T6T1 3.00;2.00;0.00 150;3 4000;4000
NAPR1043 TLLTF NA430804-2 U856 3.00;2.00;0.00 150;1 4800;4800
NBCD3004 FTLTF NB41101-1 TBU7 3.00;2.00;0.00 150;3 0;4000
NSCD0003 TLFTFNS30121-10 R1S3 3.00;2.00;0.00 150 0;4000
NSCD2017 LLTFFNS170426-3 T6Z5 3.00;2.00;0.00 150 4000;4000
NXCD9001 TTFLNX11218-5TTFL ZCU2 3.00;2.00;0.00 150;3 0;4000
RHCD4008 TFFFT RH80205-1 U2T7 3.00;2.00;0.00 150 0;4000
RHCD4009 FHHLH RH91108-1 UAC5 3.00;2.00;0.00 150 4800;4800
RSCD4006 RSCD4006 HRRS61125-2FAAT 3.00;2.00;0.00 0 0;4000
TICD4002 TICD4002 HRTI20307-2FAAT 3.00;2.00;0.00 150 4000;4000
TJCD1015 TLTTLTJ150212-4 R2U2 3.00;2.00;0.00 150,~450;3 0;4000
TJCD2029 TLFLTTJ290729-6 S7Y5 3.00;2.00;0.00 156,~450;9 0;4000
TJCD2032 FFTFFTJ321105-2 SBW1 3.00;2.00;0.00 178;150 2C000;4000
TJCD9003 TLLLTJ30205-10 Q2S1 3.00;2.00;0.00 152;5 0;4000
TPCD1003 TTLFLTP31210-1 S1X7 3.00;2.00;0.00 181 8000;4000
- clean (EAC data pre-gaps: 225) ------------------------------------------------------ 25 = 49% [TOTAL = 49%] ----------------------------------------------------------------------
HCD3051 HCD3051-4-1108-R2F V 2.74;2.00;0.00 150;1 0;4800
HMCD2002 HMCD2002-4-0113-R1F V 2.74;2.00;0.00 164;15 2C000;4000
KSCD1001 KSCD1001-5-0121-R2M V 2.74;2.00;0.00 150;1 0;0/4000
MWCD2001 MWCD2001-100525-R1P V 2.74;2.00;0.00 174;25 0;4000 pregap for Track 10 is the same as for data: 2.74
MWCD2002 MWCD2002-1-0213-R1F V 2.74;2.00;0.00 150 0;4000
SXCD2001 SXCD2001-2-0804-R2P V 2.74;2.00;0.00 150 4000;4000
TJCD1016 TJCD1016-3-0208-R1K V 2.74;2.00;0.00 150 2C000;4000
TJCD1018 TJCD1018-7-0910-R1M V 2.74;2.00;0.00 150 0;4000
- clean (EAC data pre-gaps: 224) ------------------------------------------------------ 08 = 16% [TOTAL = 65%] ----------------------------------------------------------------------
KOCD2002 KOCD2002-2-1124-R1P V 2.74;2.00;0.00 150;1 0;4000 *1: Track 13, 14
KSCD1002 TFLLFKS21017-9 RAY5 3.00;2.00;0.00 169;22 4000;4000 *1: Track 17
NAPR1039 TFTLT NA390221-1 U2Y7 3.00;2.00;0.00 150;3 4000;4000 gets -0.01 for all, from subcode it's 3.00/2.00 plus some sections set as pause @ the start of the next track (A->D), AFRAME messed up
NAPR1051 HTLTT NA511026-4 VAW8 3.00;2.00;0.00 150 2CEB0;56B8/0 *4: Track 02; all audio tracks except 1st exceed LBA
NSCD9001 NSCD9001-4-1110-R1D 3.00;2.00;0.00 150 0;4000 *2: Track 02; 1.74 track 03 AFRAME?; *3: 06,12,14,15,16
NXCD1005 TLFTFNX51114-6 RBB1 3.00;2.00;0.00 150;3 2C000;4000 gets -0.01 for all, from subcode it's 3.00/2.00 plus some sections set as pause @ the start of the next track (A->D), AFRAME messed up
PVCD0001 PVCD0001-4-0129-R1D V 3.00;2.00;0.00 150 0;4000 *2 Track 02,03; *3: Multiple
PVCD1003 PVCD1003-3-0116-R1K V 2.74;2.00;0.00 150;1 0;4000 *1 Track 07
PVCD3010 PVCD3010-1-0907-R1C V 2.74;2.00;0.00 150;1 0;4800 *1 Track 09
RHCD1001 RHCD1001-7-0615-R1F V 2.74;2.00;0.00 150;1 0;4000 *1 Track 16, 57
TJCD0007 TJCD0007-5-0219-R1D V 3.00;2.00;0.00 1238 2C000;4000 desync/*1
TJCD2024 FFLLTTJ240128-6 S1Y5 3.00;2.00;0.00 152,~450;5 0;4000 *4 Track 80
TJCD9002 TJCD9002-4-0816-R1D 3.00;2.00;0.00 150 2C000;4000/7000 Track 02 - 2.73 in EAC - *2
- minor artifacts, that resolve to 225 or 224 / 150 / 0 ------------------------------- 13 = 25% [TOTAL = 90%] ----------------------------------------------------------------------
HCD9009 HCD9009-7-1112-R1D 3.06;2.01;0.00 150 0;4000 *2: Track 02; *3: 10 audio tracks
NBCD2002 HRNB20505-4FACT 2.00;2.00;0.00 150;? 0;4000 some (10?) Mode 0 sectors at the end of last data track
NSCD0002 NSCD0002-9-0423-R1D V 3.00;2.01;?.?? 150 0;4000 A->D is detected as 2.73 by EAC, ther's some repeated AFRAME, 18.02; 05.25; 00.01; 55.57; 07.10; 29.25; 10.32
TJCD1019 HTJ191003-6FABT 2.00;2.00;0.00 150,~450;? 0;4000 some (11?) Mode 0 sectors at the end of last data track
TJCD3033 TJCD3033-2-0201-R1P V 2.74;2.02;0.00 150 0;4000 Track 02 - Mode2 next section after gap +0.01; *2: Track 03; many are 0.01 - no clue
- problematic layout ------------------------------------------------------------------ 05 = 10% [TOTAL = 100%] ---------------------------------------------------------------------
*1 last pre-gap section in subcode = Mode 2; EAC change gap +0.01
*2 A-Frame repeats @ the last gap sections; EAC change gap -0.01
*3 Desync between TOC & Subcode, 2 first sections of track are 2 last of the gap; EAC change gap +0.01
*4 last section before pre-gap in subcode = Mode 2; EAC change gap +0.01colum 'Gap Layout' list the sizes of Audio->Data (Pre-gap), Data->Audio (Post-gap) and Audio->Audio gaps and records are grouped by this characteristic.
about a half of CDs had a perfect gap layout as seen by EAC.
16% had 224 sectors pre-gap returned by EAC and indeed 224 sectors were set in subcode.
25% had some minor differences that would resolve to one of two schemes above.
10% - 5 CDs had an unique gap layout.
besides specific changes in subcode ECMA also states, that the minimum size of pre-gap is 225 sectors: 75 empty audio sectors followed by 150 empty mode 1 (in this case). and those CDs, those, that have 224 sectors marked in subcode indeed do have 225 empty secors. in fact every tested CD have (HCD9009 contains 81 audio sector+150 data; 81-75=6 hence pre-gap boost by 6 frames; NBCD2002 and TJCD1019 have 75, but they're unmarked in subcode).
also all 224 sector CDs has a ring serial of the same pattern and MWCD2001 had also a pause between two audio tracks set to 2.74 in subchannels but there were 225 empty audio sectors between those tracks. all this leads to believe, that there was something wrong with the machine that made those discs, so it would mark 1 sector less in subcode for 3 second gaps ...well, or something. mainly for this reason i asked some of mods and we agreed to go with 3seconds gap for all of them (>90%).
sometimes EAC return 0.01 or less often 0.02 gaps between audio tracks. it's mainly because of MODE=2 type sections in subcode. when ther's a pause between audio tracks on PCE, there also was so far the same amount of empty audio sectors between them: MWCD2001, NBCD2002. however this is untrue for 0.01 second gaps: there was no correlation between those gaps and silence.
also for data post-gaps there always were 150 empty audio sectors, even though sometimes EAC would return little more or less.
so all deviations, that did not exceed 2 frames mapped to 3/2/0 gaps. (also did TJCD3033. it's listed on exceptions because EAC would return a lot of 0.01 audio gaps and i have no clue why...)
so well, what i'm trying to say, ther's not really that many special CDs at the end. i guess it's mostly possible to just dump everything as 3/2/0 without even checking subcode, as long as gaps do not differ by more than 2 frames. but there are few things to remember:
1.pre-gaps for data tracks consist of two parts: audio and data, [s]both should be generated[/s] (it's hard to read, but always was empty sectors of appropriate type - nothing more so far).
update:
if your drive supports d8, please try this program: http://vigi.dremora.com/cdtoimg.rar
it will read whole cd and then you can extract data tracks with pre-gap and then unscramble and it should be ok. (please remember not to scramble audio part of pre-gap or trailing silence at the end of last data track if there is such)
maybe PerfectRip works as well, though maybe it doesn't - please try by yourself. generally when you have cue sheet and all tracks and you open this .cue with cdmage, only audio part of gaps (and trailing silence) should show up as errors on scan. if it does work, maybe it will solve those problems with incorrect gap sizes, so that would be great.
if your drive does not support d8, you can try to fake toc with an audio cd and then extract data track as sector range with IsoBuster or Cdrwin. it's described here. if escape eject doesn't work, eg. resets toc, it's possible to take drive apart and remove cd by lifting cover but please do not do this with expensive/new drive.
the reason why i do not recommend generating this data any more is because it's just more difficult - you have to check every data pre-gap anyway (it's not always 150 data sectors, though very, very rare - there can be exceptions)
2.can't dump audio track if it's followed with data and gap detected between them is larger than 3s - ther's no spare empty sectors, so audio data will be cut off. if this same track isn't preceded by another data track it's possible to reset gap in such case, if it is, you'll have to dump with and without gap and combine both files.
3.if data post-gap is detected different from 2 seconds, last expected data sector should be checked. this sector should be last valid data sector in data track. if it's audio silence or junk or next sector is still valid data - it's not right, then :)
4.when last track is data, it sometimes can have empty mode 0 sectors (some drives won't read and you may get errors) or audio silence ([s]only had this once[/s]) at the end. if it's audio silence it can get junked just like the gaps and should be replaced by clean audio sectors.
this way all data should be there and all junk left out and if something changes, about those gaps maybe, it's still possible to just shift them around - without redumping.
but if you think ther's something wrong, please, let's discuss it, ok?
.
