The PC-9801 was a very popular PC in Japan. PC-9801's design was very similar to IBM-PC, but was slightly extended. VRAM (Video RAM) is strongly extended from original IBM-PC, enabling it to display kanji characters without bitmap memory (as ASCII characters). But I/O systems, Interrupt systems are almost the same.
There were in fact three models : F1, F2 and F3. Whereas F1 & F2 models have only 128k RAM, the F3 had 256 kb RAM and 10 Mb hard-disk built-in.
More info anyone ?
Thanks to Nomura Hisayuki for the info
PC 9801 F
Full-stroke keyboard with separated numeric keypad and arrow keys
8 or 5 Mhz
128 kb (up to 640 kb)
N88-Basic + Kanji
80x25 , 40 x 25 , 80 x 20 , 40 x 20
640 x 400 with 8 colors. 2 virtual screens
One channel beeper. Built-in internal speaker
BUILT IN MEDIA
2 x 5''1/4 disk-drives
MS-DOS , N88-Disk Basic (extended Basic for control FDD)