Some corrections about the graphic capabilities of the PC Engine consoles from NEC... The CoreGrafx, SuperGrafx and TurboGrafx (US CoreGrafx) share the very same resolutions: 256x224, 336x224 and 512x224. The CoreGrafx and the TurboGrafx can display upto 512 colors out of 512; the SuperGrafx, 512 colors out of 4096. Those 512 colors are divided into 256 colors for the background, 256 colors for the sprites. Oh, and the Video RAM is actually 8 KB out of 64 KB RAM available to the console, with or without CD-ROM (8 KB out of 256 KB with a Super CD-ROM).
Aegis> R-Type on PC Engine was a nearly direct port of the arcade version. Hudson Soft released it on two HuCards (March and June 1988) for a very practical reason: the first HuCards available had a standard capacity of 256 KB (2 megabits), but the full game needed 512 KB. The two "half-games" were not labelled R-Type 1 and R-Type 2 (common misconception) but simply R-Type Part I and Part II. Later on, for the US market, the two parts were released on one single 4 Mb cartridge directly under the Irem label.

HansG> You got me interested. How did you get access to the source, since Magic Engine is shareware and David Michel (as an Amiga enthusiast) would preferably port it himself? As for Ys, the MSX versions just can't stand the comparison with the PC Engine ones (and yes, they're available in English too) :-)