The Virtual Challenger 1P is a Win32 application that simulates an (almost) fully functional Challenger 1P. It contains a complete 6502 emulator, along with all the logic required to simulate the C1P's 53-key software-polled keyboard, graphics character generator, 32x32 character display, and cassette port.
Win OSI is an Ohio Scientific Computer emulator. It emulates the Superboard II, UK101, C1P C2P, and C4P. Oddly enough, I found the newer release runs rather poorly on my Windows 7 system. For this reason I have also included the older 2002 release in the download. 1.0b release = W_Osi_2008 2002 release = OsiEmu13.exe