Microsoft Pegasus

Microsoft Pegasus was the internal codename of the project at Microsoft that hoped to create an operating system for a series of handheld computers. When the project achieved its goals and was ready to be sold to the general public, it had its name changed to Windows CE. Just like the first ever version of Windows CE, it did not support color at all.

Release History
Testing of the  Pegasus  groups output began in early 1995, under the project code name of Windows Pegasus. Pegasus was to be used on the new lines of mobile device running on specially designed hardware. Crucially the hardware requirements would be very strict. OEM's had to comply with the established guidelines. This meant that special low power hardware was mandatory. Even with 32-bit Processors these demands solved the Battery problems experienced with WinPad.

Microsoft created a reference platform specification, which the Pegasus group saw to be the ideal format for the new device. This specification was sent to the seven hardware partners signed up to produce the hardware for the new Windows operating system. The Pegasus Reference Platform dictated that all devices must be: Pegasus was also to be considerably more advanced then even consumer versions of Windows that succeeded it. Pegasus was to be a multifunction, multi-region device. To do this Microsoft needed to ensure that it had the power to expand and adapt to different markets. In making use of 32-bit processor technologies and enforcing the universal use of Unicode data through the Operating system (Unicode stores character information using a minimum of 2-bytes (16 bit's) instead of 1-bytes as with ASCII) they could ensure that the new platform could be used anywhere in the world, in any language.
 * A pocket form factor; size should not exceed 18x10x2.5 cm (7x4x1 in)
 * Power supplied by two AA batteries
 * Weigh less than 500g (1 pound)
 * QWERTY keyboard containing standard keys Ctrl, Alt and Shift)
 * LCD touch screen display of 480x240 pixels with 4 grayscales and 2 bits per pixel
 * Stylus to use like a mouse on the touch screen
 * Minimum of 4 MB of ROM
 * Minimum of 2 MB of RAM with a redundant power source
 * HPSIR compatible Infrared port
 * RS-232 Serial port
 * PCMCIA slot
 * Built-in audio output device
 * Run on the SuperH 3, MIPS 3000 or MIPS 4000 processor architecture

21 months after the  Pegasus  Group was founded, in September 1996. 6 OEM developers (Casio were the first to begin consultation on the project, followed by Compaq, HP, LG Electronics (for Hitachi), NEC, and Philips) had been signed up - based on the merits of the work carried out up to the fourth Beta release - to create devices based around the  Pegasus  system and the newly christened Windows CE 1.0 was Released To Manufacturing (RTM).

Conclusion
Later on this early existing operating system was later found to be used to test Windows CE during the alpha and beta stages later on the codename "Pegasus" was used as a codename for Windows CE 1.0 later in 1996.