The Ruputer is a wristwatch computer developed in 1998 by Seiko Instruments, a subsidiary of the Seiko Group. In the US, it was later marketed as the onHand PC by Matsucom. The Ruputer has a 16-bit, 3.6 MHz processor and 2 MB of non-volatile storage memory and 128 KB of RAM. Its display is a 102×64 pixel monochrome LCD. Its main forms of input are a tiny 8-direction joystick and 6 function buttons. It also has a serial interface and an IR port for communicating with other devices. The main body of the device (separate from the strap) is roughly 2 inches wide, 1 1/8 inches across, and 5/8 of an inch deep. It is powered by two high-powered watch batteries, which supply the device enough energy for approximately 30 hours of use. Under normal conditions, the watch goes into standby mode down when not in use in order to extend its battery life. The device was distributed with a software development kit which allows for creation of new software written in the programming language C. onHand PC The successor to the Ruputer is the onHand PC. The onHand PC was available in two color styles, clear & black, and a single format. While the Ruputer was available with either 512Kb of storage (original Ruputer), 2Mb (Ruputer PRO), or 4 Mb of flash memory (Ruputer PRO4), the onHand PC came only in a single version with 2Mb of storage. The operating system is known as W-PS-DOS version 1.16. The device features both an icon-based GUI and a text-based user interface. There is 128Kb of RAM, with an additional 128Kb of ROM. On the device, data can be entered by two methods: The first method is by using the joystick mounted to the front of the watch itself (a method that has been considered clumsy). The second method is by synchronizing data from a full-sized PC using the included software. A program called HandySurf also allows synchronizing internet content (such as Yahoo! News Headlines). Communication with other devices is either through a 38,400 bit/s serial port dock, or through the 9,600 infrared link, the transmitter of which is mounted to the upper middle of the watch. It is possible to link two onHands via this infrared link to play various two-player games. The watch uses two lithium CR2025 button cells for power, which can be accessed from the back of the