Firstly: you need some ZX Spectrum emulator. If you have some SoundBlaster,
you may check X128. The emulator should support TAP files and emulate ZX Spectrum
128. After you got your emulator running, choose the TAP file with demo (in
X128: F7). Choose ZX Spectrum 128 emulation and reset this emulated Speccy (X128:
F3). Now you should see a menu with "Tape loader", "128 basic", "Calculator",
Choose "128 basic" (down arrow, or some of Shift/Alt/Ctrl with 6 and enter) Write "usr0" and hit enter. After you got a copyright message, hit "j". You should get a "LOAD" command at screen. Now write 2 quotes ( Shitf+' or some of Ctrl/Alt/Shift with "p" ). Now, if you have at screen something like LOAD "", hit enter. That's all. It's possible, that some demos will work directly after choosing "Tape loader" menu item, or "48 basic" and then LOAD "".
Or some of them may be runable even at ZX Spectrum 48 emulator. But most (?) of demos you must start with this 128 basic, usr0, LOAD "" sequence to get them work correctly.
Anyway, if you haven't seen any demo for ZX before, and you don't know even, what computer is Speccy, than you should check our demo "YES", which contains many "at-the-edge" effects, and it's absolutely best from our ZX production. If you wouldn't like "YES", not even a little bit, than we don't think, that you will like any other Speccy demo. Not ours, nor others. (Because YES is surely in TOP 25 of world best demos for Speccy). Ped and Pavuk of course love nearly everything for Speccy. And they don't tell you, how ugly and terrible Pamela Anderson is ... So, try to tolerate us. (BTW, did I told you, how terrible Pamela is? No ? So I would rather not even tell you...)
And still one more thing. If you have problems to run something, getting strange
messages as "nonsense in basic", or you have problem to run DB96 invitation
intro. You may try to fix these problems by yourself.
Use command MERGE "" instead of LOAD "". Command MERGE could be entered by hitting Shift+Ctrl (cursor should change from "K" to "E", if not, try again, or other combination of Shift/Ctrl/Alt keys). Then hit Shift+T. (if it writes "RND", try other key, than shift). This will load the basic loader of demo, but it will not run it. Now you may check for the problem. (if you know something about basic) In DB96INV intro there's problem with HW detection code, which usually hangs at emulators (because it's nearly impossible to emulate Speccy so good to make this test work). This HW detection will be switched off by hitting "3" and enter. (this will delete line 3, where the test is executed). Now hit R (RUN) and enter to run it.