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Author here. Thanks for the kind words. It was fun to do, and I just wish I could have touched on stuff like FAST vs SLOW, more about the weird display system,
by david-given 8y ago
Author here. Thanks for the kind words. It was fun to do, and I just wish I could have touched on stuff like FAST vs SLOW, more about the weird display system, etc... but TBH FAST doesn't really get on well with modern monitors and video capture systems and I was terrified of getting 40 minutes into it and then discovering that all my captured video was unusable!
Oh, yeah: ZX81 BASIC doesn't support multiple statements per line, and the IF...THEN statement doesn't support ELSE. Writing complex logic on it can be a challenge!
- dukoid 8y agoIs there any advantage in using A, B, C etc. as variable names? W and H seemed to be potentially more readable for the with and height, X and Y for the ball position and in particular O and I for 0 and 1 etc.? Also, I think I have spotted a few remaining 0s in the saved file?
- david-given 8y agoThe practice version did, but name collisions got too confusing (W and H is fine for width and height, but then I wanted horizontal and vertical velocity...). I thought it was clearer to give up completely and use the notepad instead. And yes, some optimisations are left as an exercise for the reader.
- rwmj 8y agoThe "canonical" FOR loop variables were always F and N (not Z!), because you could type "FOR F" and "NEXT N" quickly (F F and N N respectively). What I really liked about the ZX81 and I think you demonstrated well is how interactive programming is. Just run your program at any point to see progress. Commonly used modern programming environments aren't as good in this respect.