It was dumb. I found the answer in a previous post. Sorry.

> This may be a really dumb question but I've just downloaded the ROM for
> Defender (Red) and tried to run it via MameCE on a Casio EM-500 (MIPS). I get a
> screen telling me to press "OK" if I really own the ROM. I don't have a
> keyboard and I can't call up the onscreen version. How do I type "OK" ?
>
> Russ Smith,
> retrogamer newbie
>