FM Towns - Details

Details

Several variants were built; the first system was based on an Intel 80386SX processor running at a clock speed of 16 MHz, with the option of adding an 80387 FPU, featured one or two megabytes of RAM (with a possible maximum of 64 MB), one or two 3.5" floppy disk drives and a single-speed CD-ROM drive. It was delivered with a gamepad, a mouse and a microphone.

The earlier, more distinctive models featuring a vertical CD-ROM tray on the front of the case (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 100ns or less and a recommended timing of 60ns.

Hard drives were not standard equipment, and were not required for most uses. The OS was loaded from CD-ROM by default. A SCSI Centronics 50/SCSI-1/Full-Pitch port was provided for connecting external SCSI disk drives, and was 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, however the power supply module does not typically provide the required Molex connector to power the drive.

The video output was RGB using the same DB15 connector and pinouts as earlier Apple Macintosh computers.

The operating system used was Windows 3.0/3.1/95 and a graphical OS called Towns OS, based on MS-DOS and the Phar Lap DOS extender (RUN386.EXE). Most games for the system were written in protected mode Assembly and C using the Phar Lap DOS extender. These games usually utilized the Towns OS API (TBIOS) for handling several graphic modes, sprites, sounds, a mouse, gamepads and CD-audio.

A minimal DOS system that allowed the CD-ROM drive to be accessed was contained in a system ROM; this, coupled with Fujitsu's decision to charge only a minimal license fee for the inclusion of a bare-bones Towns OS on game CD-ROMs, allowed game developers to make games bootable directly from CD-ROM without the need for a boot floppy or hard disk.

To boot the system from CD-ROM disk, the FM TOWNS had a "hidden C:" ROM drive in which a minimum MS-DOS system, CD-ROM driver and MSCDEX.EXE were installed. This minimal DOS system ran first, and the DOS system read and executed the TownsOS IPL stored in CD-ROM disk after that. The Towns OS CD-ROM disk had an IPL, MS-DOS system (IO.SYS), DOS extender, and Towns API (TBIOS).

Various Linux and BSD distributions have also been ported to the FM Towns system, including Debian and Gentoo. A version of GNU called GNU for FM Towns was released in 1990.