Programs can be run directly on the command line. Doing so loads them much faster than reading from virtual cassette files and without the hassle of writing them to a virtual disk image. Files in "DOS" format (.cmd) are run at the TRS-DOS prompt. Other machine language files and BASIC programs are run at the ROM BASIC READY prompt or at machine boot for Model 2 and 4P which don't have a ROM BASIC.
It may not be obvious that this direct running of programs is not the way the TRS-80 normally loads and executes programs. Some programs may not work especially disk BASIC programs. However it is very useful for program development and is otherwise extremely handy when it does work.
To give it a try, download the emulator and also my bouncing ball demo program. You can run it directly from the .zip archive:
trs80gp ball.zipWhich will prompt for which file to use. Or specify the file inside the .zip archive directly like so:
trs80gp ball.zip?ball.casOr you can extract the virtual cassette file yourself and run it:
trs80gp ball.casYou can load machine language programs in .cmd, .hex and .bds formats. My Z-80 cross assembler zmac produces all three formats and with .bds you get full source-level debugging and memory fault detection (see Debug → Z-80 Debugger... and Debug → Source Code...).
It also can load BASIC programs in tokenized form or plain ASCII.
There's so much more! But I'll leave it at that and spend the rest of this page more in "reference manual" mode.