About Saturn, Sega CD, PC-Engine CD/Turbo CD, CD-I, 3DO, and Neo Geo CD, you can rip using cd command.

* Ripping Guide for CD
 DiscImageCreator.exe cd [DriveLetter] foo.bin [DriveSpeed(0-72)]

 For secure ripping, I recommend using /c2 option
  DiscImageCreator.exe cd [DriveLetter] foo.bin [DriveSpeed(0-72)] /c2
 
 About others option, run exe without args to get detail info.

About dreamcast

* Ripping Guide for GD-ROM (The high density area)
** Preparation
 create the audio trap disc in advance.
 (a disc with a hacked TOC of 99 mins audio, burn it with CloneCD or Alcohol 52/120%).
   http://www.mediafire.com/?2nygv2oyzzz

** Method 1 (Other tools)
 http://forum.redump.org/topic/2620/dreamcastnaomi-gdrom-dumping-instructions/

** Method 2
1. insert the audio trap disc to a supported drive.
2. run below. (stop spinning disc)
   DiscImageCreator.exe stop [DriveLetter]
3. use a pin to press the escape eject button, so the tray will eject (or remove
   the drive cover).
4. insert the gdrom and gently push the tray back (or put the drive cover back on).
5. run below. (start rippping gdrom)
   DiscImageCreator.exe gd [DriveLetter] foo.bin [DriveSpeed(0-72)]

We use the DIC method now and a Plextor with  px_d8 support. See the DiscImageCreator thread for the actual program and instructions, and keep the log files.

That thread is QUITE long and doesn't seem to provide explicit instructions on how to rip each format, in its own section to make things clearer.

If there any way of getting individual system instructions at all?

I have Saturn, Sega CD, Dreamcase, PC-Engine CD/Turbo CD, CD-I, 3DO, and Neo Geo CD that I'd like to dump in some recognized format on a regular basis.

The dumping method is pretty much the same like years ago, with advanced use of DIC.
F1ReB4LL will be answering your question more detailed if he read this, or you contact him privately.

Just repeating myself to bump your question.

thank you

For the xM, xS stuff, I am not quite sure I got it but it does not really matter.

Different pressings of the same version of the game with different checksums. xM, xS, xA, etc. are taken from the ringcode.

In short -- these come from the ringcodes, so they are used to distinguish the different prints of the same game.

Dump game as in the standard guide, but if you find one of the situations below you have to submit a subchannel dump (.sub) taken only with CloneCD to check possible EAN or mastering errors and / or to determine real pregaps, etc.

How about a little explanation on the sub-channel interpretation?
Maybe an easy scenario (2sec gaps) and the hard ones (1.74sec) and (0sec).

:EDIT:

Ok figured out is it sector 0 on the disc viewed in ISOBuster