Several variants were built; the first system (FM TOWNS model1 and model2) is based on an
Intel 80386DX processor running at a clock speed of 16
MHz, with the option of adding an
80387 FPU, features one or two
megabytes of
RAM (with a possible maximum of 6 MB), one or two 3.5"
floppy disk drives, a
PCMCIA memory card slot and a single-speed
CD-ROM drive. Its package includes a
gamepad, a
mouse and a
microphone. The earlier, more distinctive models featuring a vertical CD-ROM tray on the front of the case (model1, model2, 1F, 2F, 1H, 2H, 10F and 20F) were often referred to as the "Gray" Towns, and were the ones most directly associated with the "FM Towns" brand. Most featured 3 memory expansion slots and used 72-pin
non-parity SIMMs with a required timing of 100
ns or less and a recommended timing of 60ns. Hard drives are not standard equipment, and are not required for most uses. The OS is loaded from CD-ROM by default. A
SCSI Centronics 50/SCSI-1/Full-Pitch port is provided for connecting external SCSI disk drives, and is the most common way to connect a hard drive to an FM Towns PC. Although internal drives are rare, there is a hidden compartment with a SCSI 50-pin connector where a hard drive may be connected, but the power supply module does not typically provide the required
Molex connector to power the drive. The video output is 15 kHz
RGB (though some programs used a 31 kHz mode) using the same
DA15 connector and pinouts as the PC-9801.
Operating system The
operating system used is
Windows 3.0/3.1/95 and a graphical OS called Towns OS, based on
MS-DOS Graphics The FM Towns features a custom Fujitsu graphics chip, enabling video modes ranging from 320×200 to 720×512 resolutions, with 16 to 32,768 simultaneous colors out of a possible 4096 to 16 million (depending on the video mode); most of these video modes have two
memory pages, and it allows the use of up to 1024
sprites of 16×16 pixels each. It also has a built-in font
ROM for the display of
kanji characters. The system has the ability to overlay different video modes; for example, the 320×200 video mode with 32,768 colors can be overlaid with a 640×480 mode using 16 colors, which allows games to combine high-color graphics with high-resolution kanji text. It uses 640
KB of
video RAM, including 512 KB
VRAM and 128 KB
sprite RAM.
Sprite layer: •
Sprite RAM: 128
KB (8 KB attributes, 120 KB pattern/colour data) • Overlay support: Bitmap modes 1-11 • Pentium (Socket 5/90 MHz): Fresh GT, Fresh GS • Pentium (Socket 5/120 MHz): Model H
Sound The FM Towns system is able to play regular
audio CDs, and also supports the use of 8
PCM voices and 6
FM channels, using the
Ricoh RF5c68 and
Yamaha YM2612 sound chips, respectively. The system has ports in the front to accommodate
karaoke, LEDs to indicate volume level, and software to add popular voice-altering effects such as echoes. Games on the FM Towns regularly use
Red Book Audio CD music tracks, especially if they are designed specifically for the Fujitsu system. Games ported from the PC-9801, for instance, might have used only PCM/FM music. This was a novelty and innovation far ahead of other PCs of the time made possible by the standard CD-ROM drive found in every FM Towns computer.
Ricoh RF5c68 The
Ricoh RF5c68 is an eight-channel
sound chip developed by
Ricoh. It is notably used in Fujitsu's FM Towns computer series, along with
Sega's System 18 and
System 32 arcade game system boards. The RF5c68 supports eight 8-bit
PCM channels, with 19.6
kHz or variable
sampling rate.
Audio bit depth ranges from
8-bit to
10-bit. == See also ==