I've taken another look at the igs_blit.c driver, thanks to Pierpaolo, who managed to decrypt another Mahjong game, Da Ban Cheng.
I've added the necessary protection patches / emulation so that it work. While I was at it, I took the chance to clean up the driver, and review the protection handling in the non working games there.
I managed to promote to working status the following games: Xing Yen Man Guan (with help from Wei Mingzhi), an earlier version of Long Hu Bang, an alternate world version of Dragon World along with its Hong Kong and Chinese variants (Zhong Guo Long).
Below are the title screens of Da Ban Cheng and "Zhong Guo Long" (Hong Kong) (actual Taiwanese title?):
I've also marked the world version of Virtua Bowling as a bad dump, patching it so that it doesn't reset at the end of a game.
The issues still open in this driver are now some lingering palette problems and, of course, proper emulation of the IGS011 and IGS012 ASIC's.
Unrelated to the above, I've been doing some work (mostly released by now) on several obscure games, ending up with a preliminary driver for the protected Korean game Quiz Punch 2, a couple of working video pokers – Champion Poker, Galaxi – and some minor improvements to Table Tennis Champions (still working on that).
