Can you believe it! First day of the month and I have a program uploaded! Okay, so it is another graphic one and isn't very exciting, or long. But hey, you can't blame me for not trying!
May's program is BOLT from 1984. It creates a lightning bolt with a circle and embossed BOLT logo. Cool huh? The original program actually printed out the screen five times using the COPY command, but that seemed silly online. To that end, I removed those lines of code. Also, because I couldn't find the code, I removed a screen inverse routine. If I find the code, or another way to do it, I'll post that later.
This program uses a simple line drawing subroutine to generate the bolt. The circle is also calculated. This keeps the program small, but like the last one, means it can be a bit slow. Running it in FAST mode speeds things up, but you can't watch it draw the image. The logo is simple PRINT AT and ZX81 graphics. Much faster to display, but a bit harder to type in.
That's it! Simple and easy. Enjoy May!