Free42 was written from scratch, without using any HP code. You do not need any ROM images in order to use it, yet it is fully HP-42S compatible.

Update Description:
v1.4.43 (12-04-2008):
- MacDashboard version: fixed event handling so that program execution now works. There's still plenty of room for improvement: key timeouts (so pressing and holding a key behaves like it does on the real HP-42S and on the other Free42 versions) and auto-repeat come to mind... But at least programs, the solver, the integrator, and interruptible matrix functions should all be usable now.

v1.4.42 (10-03-2008):
- Added a HI_RES_AWARE resource so that Free42 will now be able to take advantage of high-resolution displays without the help of Tweaks2k2 or similar utilities.