hidden bomberman game on the 3-in-1 disc, game plays without disc spinning?

[GameFreak]

So I finally got a hang of the bomberman game. I recently bought the disc 3-in-1 with Gate Of Thunder, Bonk, Bonk revenge and the hidden Bomberman. So I was playing it for a while and I decided to pause it for about 20 minutes. When I returned I noticed through the little window on the cd drive that the disc was not spinning at all while paused  . I sort of remember all my other games spinning even when paused. Maybe they do stop spinning when paused.
....BUT the REALLY weird thing was when I unpaused the game and started to play again the disc is still not spinning? How am I playing a game without the disc spinning? I'm confused. Does it load the bomberman data onto the IFU or...?

I just played for a few minutes without the disc moving. WTF?   

Ok so later on today I tried to recreate this by pausing it for 20 minutes and the disc kept spinning during pause and continued spinning when I unpaused. That seems normal. So I tried it one more time (to prove I wasn't going mad) by pausing it and the disc DID stop spinning and when I unpause it I can play it WITHOUT the disc spinning like it did the first time. Is that weird or normal?

note: I'm using the japanese IFU setup with an arcade card pro that's why I post here and not in the tg16 section.

BTW is this the full game of bomberman or just some stages to try out?

[Tatsujin]

It is the full game.

I assume it is partly loaded into the system ram, so the disc don't have to spin all the time. music is PSG as well, so no probs there.

[GameFreak]

It is the full game.

I assume it is partly loaded into the system ram, so the disc don't have to spin all the time. music is PSG as well, so no probs there.

That's good to know. I guess it's a lot less stress on the little plastic gear if it's not spinning, but you gotta trick it to stop spinning with the pause button.

[ccovell]

It is fully loaded into the System RAM.  The Super CD unit has 256k system RAM, so it can hold and run 2M games in their entirety.

[nat]

The disc also stops spinning for the two Bonk games, which are 3 megabit and 4 megabit, respectively. The Bonk games will spin up the disc periodically, however, as needed to load the next block of data into RAM.

[Tatsujin]

It's like the first Ridge Racer on PSone. Once the game was fully loaded you could just replace the game by a normal audio CD and then choose your own music tracks.

So beside the red book audio, everything else could fit into the small 1MB Ram of the PSone.

[SignOfZeta]

I think any PCE CDROM game will do this as long as the disc doesn't need to be accessed. Most games have redbook music playing non-stop though so you rarely see it.

[Black Tiger]

Kabukiden has a trick printed in the manual stop and/or play CD music. So you can swap in a custom CD to listen to while grinding.