Phoebe (computer) - Operating System

Operating System

During the years following the release of the Risc PC, Acorn had discussed using an alternative to RISC OS as their next operating system, using TAOS or writing their own microkernel-based operating system Galileo. However for the launch of Phoebe 2100 an enhanced version of RISC OS would be developed, called RISC OS 4 (codenamed 'Ursula'). RISC OS wouldn't support the multiple processor daughter cards that had been included in the Phoebe 2100 hardware specification.

RISC OS 4 had to support the new hardware of Phoebe 2100 which wasn't present in Acorn's earlier machines;

• PCI expansion slots
• Support for multiple serial ports
• The PC style game port, supporting joystick and MIDI

In addition several new features were to be added to the core of RISC OS;

• A better file system, increasing the number of items in directory from 77 to approx 88,000 and increasing the max length of a filename from 10 characters to 255
• A plugin based system configuration utility.
• A new screensaver API
• An enhanced window manager
• An updated interactive help application
• A redesigned set of icons

To prepare developers for the changes to the OS, Acorn released to its 'Registered Developer' program RISC OS 3.80, designed to load on Acorn's previous generation Risc PC and A7000 computers. This would enable developers to test that their software would be compatible with Phoebe 2100, provided it didn't require any of the new hardware features. RISC OS 3.80 was limited, it only ran on ARM6 and ARM7 Risc PCs and not StrongARM (ARM4) based ones. Testing of hardware compatibility would have to wait until an initial run of 100 or so pre-production machines was made available to Registered Developers.