Playstation 1 games that have "vertical arcade modes":

1 DonPachi
2 Do DonPachi
3 Geki-Oh Shienryu (I think this has the same features as the Saturn version and more)
4 Gunbird
5 Raiden DX
6 raiden project
7 Sonic Wings Special
8 Strikers 1945 part 1 (according to my friends of the shmups forum does excist, and they don't mean the agetec conversion of part two.)
9 Strikers 1945 part 2 only the Japanese & the now recently released European version.
10 Toaplan Shooting Battle 1 (kyukyoku tiger/twin cobra collection)



Note* Capcom Generation 1,3 & 4 have vertical arcade modes, but Capcom didn't convert (stretch) the original arcade games which have a different resolution as the Playstation's. This results in top and bottom borders!
These arcade games where released on Capcom arcade system released prior to the CPS-1.

Mercs (Capcom generation 4) however is the only game in all of the 5 volumes that does have a proper fullscreen vertical arcade mode, because that game was originaly released on the CPS-1 Capcom arcade system.
CPS-1 has a 320X240 resolution that corresponds with the Playstation's 320X240 resolution.

The volumes:
Capcom Generation 1 1942, 1943, 1943 KAI (remix of 1943)
Capcom Generation 2 Ghosts 'n Goblins, Ghouls 'n Ghosts & Super Ghouls 'n Ghosts
Capcom Generation 3 Exed Eyes, Pirate ship Higemaru, Son son, Vulgus
Capcom Generation 4 Commando, Mercs, Gunsmoke
Capcom Generation 5 SF2, SF2', SF2' TURBO



Playstation 1 games that don't have "vertical arcade modes":

Strikers 1945 part 2, the American version