sdltrs (Radio Shack TRS-80 Model I/III/4/4P Emulator) sdltrs is a Radio Shack TRS-80 Model I/III/4/4P emulator for Macintosh OSX, Windows and Linux. It has been ported from the excellent X Window Unix emulator xtrs. Instead of using the X-Window system for graphics, it uses the portable SDL library. This build uses SDL-1.2, which is an older library that performs better on older and lower-spec machine. If your computer was made in the last 10 years or so, you probably should be using the SDL-2.0 build, which is called sdl2trs. It's possible to install both sdltrs and sdl2trs on the same system without conflict. Note: When you start up sdltrs for the first time, it attempts to boot from floppy disk. If you didn't give either the "-disk0 /path/to/image.dsk" or "-nofloppy" options on the command line, it will "hang" with a black screen, because it's trying to boot from a nonexistent floppy disc. To recover from this: - Hold down F10 (TRS-80 Reset) and press Escape (TRS-80 Break key) to skip the disk boot and enter the ROM BASIC. - Press Alt+D to enter the emulator's disk menu, and from there, either select a bootable disk image for drive 0, or disable the floppy disk controller. Then press Shift-F10 to reboot the TRS-80. See the man page and the documentation at /usr/doc/sdltrs-$VERSION/html/index.html for further details.