I absolutely adore PC98 art, both for the aesthetic style and the superb pixel work. Though I've always wondered if it was drawn by hand or they had a compression tool/graphics converter or something - I've seen people say it was done by hand, and others say that there were tools to compress the images down to 16 colours without losing clarity. Not sure if anyone in here would know, but did such a tool exist? (...and is there any information on it?)
The vast majority of PC-98 games were created by hand using programs like this:
A lot of these had tools for dithering and palette editing similar to Deluxe Paint etc. Powerful tools for pixel art.
Here are examples of hand drawn art:
However, there are a few games that use art that has been digitised directly down from larger pieces. Here are some examples of digitised art:
I think as the years went on people (and software) got better at working with media and graphics. Towards the later years of the PC-98 artists started doing pretty fancy stuff with aliasing and vectors to achieve smoother manga/anime styles. As much as I love the pixel art from that era, it seems that the actual artists creating stuff on the PC-98 were enthusiastic about making it look more realistic.
It's probably going to be a long while, but Puu the Japanese developer who is working on the Sharp X68000 FPGA core he's porting to MiSTer, and just released a PC-88 core has said he's developing an NEC-9801 core. That's the very early 8086 based PC, but hopefully, the 386 and 486 models will come in somewhere down the road.
The console and arcade cores get the main focus of people talking about the MiSTer. But the computer cores are fun to tinker with and don't require 30-40-year-old hardware that wasn't as widely produced as the consoles.
Thanks very much for the explanation, CitizenHal! I ask as I've been trying my hand at making PC98 style art, and spent a long time looking over pieces from different games to get a feel for the limits of the technology and the type of things the artists used to get around that. Some of the more complicated ones look like traditional art just ported into the PC98 wholesale, but I guess they did just have to draw it straight into the art software until it looked right (though very interested in those art programs you showed, I'm going to take a look at those...)
A lot of PC-98 games are adult games. So that takes a good whole chunk of the PC-98 library.
Some people have gave estimates of the percentage of adult games on the system like 90%, but according one site that compiles info on PC-98 games its over 80%. So its safe to say that 80~90% of PC-98 games are adult games.
The PC-98 wasn't capable of sprites unlike its rival the FM Towns. Because of this drawing the screen took longer than you would expect for a game.
This is the same reason why a lot of IBM PC action games from the 80s were stiff and jerky.
So that's why there are a lot of eroge for the PC-98.