Denial

I'm glad to see you sorted it out. :) Thanks! Do you have any ambitions to port the program over to use MINIGRAFIK? I've come across MINIGRAFIK a few times and had a look at the API and it is admirable. It's more that I'm interested in programs that fit on an unexpanded machine. Hence the Conway's ...

I found out the real problem. There are overflow errors in the original calculation. As it stands, 4:12 arithmetic doesn't provide enough integer bits, because some values for X can be ≤0xc000 or ≥0x4000. Consequently, when X2 is generated and occasionally when X2+Y2 are generated, there's an overfl...

From the source I see you add the two squares z.Re² and z.Im² to calculate the magnitude squared of z, i.e. |z|². That's o.k. (I use the same method in my own program), but that value should then be compared with 4, actually Yes, it should be doing that, because in 4:12 fixed-point arithmetic the v...

You should check the bail-out condition, though. It seems you're using a lower value than 2 in |z| >= 2, which introduces visible artifacts (see the red-yellow stripe in the large blue area, repeated via self-similarity into the deeper iteration bands). You’re right, I thought there might be some m...

Hi folks, For probably my last VIC-20 program of the year, I thought I'd write a colour Mandlebrot program for the unexpanded VIC-20, as a bit of a foray into multi-colour bitmapped graphics. The code is actually based on the modifications I submitted to Ken Shirrif's Mandlebrot generator for the Xe...

Rocket Command.. Tank-v-UFO .. Killer Comet. So, Blastar isn't quite the same as any of these, but there are some similarities with the first two. My Games Collection also contains these other two programs, Rocket Command and Killer Comet, so you can do the comparison by yourself. Earlier this year...

No, it's not that. It much simpler. Just an "up arrow" in the middle on the bottom, and a greater than/less than sign that went across the top. You timed the firing of it and hit it, or not. Thanks, I feel vindicated ;-) And motivated enough to write another Blitz program in BASIC for the...

This is no different than the game that comes in the VIC manual.

Really? Elon Musk started out with a VIC-20, so it would be quite ironic if he ported a VIC-20 manual's game to the Spectravideo, which eventually got ported back to the VIC-20

Can you point to the VIC-20 manual's version?

it's quicker to just poke the graphics themselves directly to the screen That wouldn't surprise me, I wouldn't say I was the most expert VIC-20 programmer :-) It would mean a line such as line 150 becoming: 150 A=G*22+H:POKE 7681 +A,63:POKE 7680+A,160: POKE [Color RAM]+A,Color Yes, that's probably ...

Back in 1984, the 12 year old Elon Musk wrote a rudimentary video game for his SpectraVideo SV-328 (a Z80 Microcomputer) https://www.theverge.com/2015/6/9/8752333/elon-musk-blastar-pc-game Then about 5 years ago someone turned it into an HTML-5 version of the game which you can play here: http://bla...

Hi Mike, You were right, there was an issue at Generation 1412 as you say. I found the issue and corrected it. The problem was that the assembler I use: mac2c64 didn't calculate kBmEndColDn .equ 3200-kBmH+1 correctly. It should have resulted in the value 3041, which is the relative displacement from...

Hi Mike,

Thanks for that - I re-ran from scratch and couldn't see that pattern up to 200 generations. I was running it under xvic (VICE). If someone comes across it with generation numbers then that'd be helpful.

Thanks for the feedback. I'd suppose you also need to copy the *last* byte of each screen row to the position *before* the cached line so you have 22 bytes per row. Effectively, the code should already be doing that. The code caches the previous and current row, but this is in turn cached into 3x3 b...

HiUxLife is a hi-resolution (160x160) version of Life for the Unexpanded VIC-20. https://sites.google.com/site/libby8dev/home/vic20/HiUxLife.png I really wrote it in order to experiment with both 6502 coding (of which I haven't done a great deal) and as an experiment in coding a bitmapped program fo...