Prism v0.2.1 — first public release

Prism is a Finder-style graphical desktop for the Color Computer 3, running on NitrOS-9 EOU: menu bar, drive icons, draggable windows, double-click program launching, a launcher button and a menu-bar clock, at 640x200 in colour or classic mono. Written from scratch in C. Free and open source (MIT) — a gift to the CoCo community from Keith Clark of Rodney, Ontario, designed and built with Muse.

New download — the boot package (added November 5, 2026): prism-0.2.1-boot-package.zip is the easy way to try Prism in MAME. It contains EOU's emulator boot floppy (63EMU.DSK), an EOU system hard-drive image with Prism 0.2.1 installed and set to start automatically (PRISM_HD.VHD), a blank user drive (EOU_USER.VHD), and a README with exact steps.

Why a package? Curtis Boyle, EOU's maintainer, explained the design: in an emulator, EOU's floppy only starts the boot — the hard drive finishes it. On real hardware with a hard drive, you boot from the hard drive outright. So the boot is a handoff:

mame coco3h -ramsize 2m -flop1 63EMU.DSK -hard1 PRISM_HD.VHD -hard2 EOU_USER.VHD -mouse -window

Type DOS at the Disk BASIC prompt and the boot runs hands-free into Prism. Prism opens on its own window — press CLEAR (the Home key in MAME) to cycle through the windows to reach it. One setting matters: in MAME's Machine Configuration, set "Hi-Res Joystick Interfaces" to NONE, or the mouse pointer will not move.

This boot was verified end to end in MAME 0.275 on November 5, 2026.

About the standalone disk: prism-0.2.dsk still does not finish booting on its own in MAME — that is EOU's design, not a corrupt image. Use the boot package for MAME, or copy CMDS/prism from the disk into your own running EOU system and type PRISM. On real hardware / CoCoSDC the disk uses the standard NitrOS-9 boot recipe throughout.

Downloads: prism-0.2.1-boot-package.zip (MAME boot package), prism-0.2.dsk (disk image), prism-0.2-src.zip (full source, docs and build scripts), README.txt.

NitrOS-9 EOU 1.0.1 is by L. Curtis Boyle and the EOU/NitrOS-9 community; the boot floppy and system image in the package are EOU's, included so Prism can be tried the way EOU was designed to run.