rate as 1232 KB 8-inch floppy disks. They became a non-standard format while formats brought by IBM PC/AT and PS/2 became the industry standard. The PC-98 supports up to four floppy drives. If the system is booted from a floppy drive, MS-DOS assigns letters to all of the floppy drives before considering hard drives; it does the opposite if it is booted from a hard drive. If the OS was installed on the hard drive, MS-DOS would assign the hard drive as drive "A:" and the floppy as drive "B:"; this would cause incompatibility among Windows PC applications, although it can be resolved with the SETUP command in Windows 95 by turning on the "/AT" switch to assign the Windows system drive to the standard "C:" drive. The PC-98 uses several different interfaces of hard drives. Early models used Shugart Associates System Interface (SASI) or ST506, and later models used SCSI or IDE drives. Graphics A standard PC-98 has two µPD7220 display controllers (a master and a slave) with 12 KB and 256 KB of video RAMs respectively. The master display controller provides video timings and the memory address for the character generator, and the character generator generates a video signal from two bytes of the character code and a single byte of the attribute. The font ROM contains over 7,000 glyphs including the single-byte character set JIS X 0201 and the double-byte character set JIS X 0208, although early models provided the double-byte character set as an option. Each character has a variety of display options, including bits for secret, blinking, reverse, underline, and three intensity bits (grayscale or RGB). The other display controller is set to slave mode and connected to 256 KB of planar video memory, allowing it to display 640 × 400 pixel graphics with 16 colors out of a palette of 4096. This video RAM is divided into pages (2 pages × 4 planes × 32 KB in 640 × 400 with 16 colors), and the programmer can control which page is written to and which page is output. The slave display controller synchronizes with the master, so the text screen can be overlapped onto the graphics. The high-resolution machines (PC-98XA, XL and PC-H98) offered an 1120 × 750 display mode and aimed for tasks such as CAD and word processing. The PC-9801U (optional) and VM introduced a custom chipset GRCG (GRaphic CharGer) to access