The Vintage Computing Christmas Challenge 2024

[Prodatron]

One year passed, and here is the new challenge for 2024:



https://logiker.com/Vintage-Computing-Christmas-Challenge-2024

This time it's a "present/gift".
Looking forward to it again, always crazy with how less bytes some people are able to do this on different platforms.

@Logon System, you have to go for it again!

[lightforce6128]

Also looking forward to it. This time it seems there is less symmetry that could be used to shorten the program. But we will see ...

[Prodatron]

This time it seems there is less symmetry that could be used to shorten the program.

Another problem is, that this time there are 7 different chars in total (including space, excluding line feed).
In the past you always had only 2 chars (including space).

So I wonder, if the entries will be larger this time.

[GUNHED]

Here is my first result, no optimisation at all.

It needs &48 Bytes = 72 Bytes

See picture...

[Overflow]

@Logon System, you have to go for it again!

Go!

So I wonder, if the entries will be larger this time.

They will. No doubt they will. That said it also implies many ways to optimize. Nice challenge - different from last year.

It needs &48 Bytes = 72 Bytes

Almost the same at first shot (70 bytes). Now let's optimize.

[GUNHED]

First optimisation: Down at &40 = 64 Bytes.

[Prodatron]

With my very first approach I am at 58 bytes, and it seems to be hard to decrease this.
Another idea is needed to reach less bytes.

[BSC]

Nice compo. Good to see your participation @Overflow 

My first try is under 60 bytes. I hope to squeeze one or two more bytes. 

[ZorrO]

101 bytes in CPC Basic. 

[ZorrO]

99 bytes, no more ideas. 

[lightforce6128]

99 bytes, no more ideas. 

First I tried with BASIC, three different approaches. But none of them is even close to 99 bytes. So this seems to be a good achievement ... for now.

[lightforce6128]

I find it always surprising how close the assembly solutions are and also how similar the improvement steps are. I implemented two assembly solutions, and with the "Ready" prompt at a bad location I also achieve less than 60 bytes. But the prompt needs to move somehow ... (letting the prompt appear saves some bytes compared to halting the program, but moving the cursor to a good location eats up the improvement again).

While working with this a bit I have to correct myself: There are many symmetries, in the image itself as well as in the numbers.

[arnolde]

Nice challenge!

I'm at 54 bytes now, but I wonder what Logiker means by 
"All characters can be replaced with another character if this does NOT influence the code."

Does he mean we're not allowed to replace the symbols with others that look similar but have an ascii-code that happen to be useful as constant, opcode or other?

[ZorrO]

I think for example ZX80 & ZX81 don't have ! and \ but you still can use it as challenge machine.

[andycadley]

Nice challenge!

I'm at 54 bytes now, but I wonder what Logiker means by
"All characters can be replaced with another character if this does NOT influence the code."

Does he mean we're not allowed to replace the symbols with others that look similar but have an ascii-code that happen to be useful as constant, opcode or other?

I don't think that would be allowed, since then the symbols used literally affects the code. It's really an exception for machines whose character set doesn't contain suitable characters.

[Prodatron]

Nice challenge!

I'm at 54 bytes now, but I wonder what Logiker means by
"All characters can be replaced with another character if this does NOT influence the code."

Does he mean we're not allowed to replace the symbols with others that look similar but have an ascii-code that happen to be useful as constant, opcode or other?

It means, that if using characters, which

- are NOT originally specified; see here...

The characters used are:

• - Minus
• + Plus
• ! Exclamation mark
• \ Backslash
• / Slash
• O Big O

All characters can be replaced with another character if this does NOT influence the code. E.g. backslash on the C64 gets replaced by chr$(205). Or on the right-hand side I replaced the big O by a smaller one, as it looks nicer, but it didn't influence the code. At any time, I could replace the o with O or the C64 Backslash with its counterpart on the C64.

- AND will change/optimize your code

are NOT allowed.

Probably the best example is using "*" instead of "-" (you probably know, what this could mean ). This of course is not allowed.

PS: Hope Logiker isn't angry, that people are posting their current sizes, as this is against the rules, but I did this mistake as well in the past, sorry...

[arnolde]

Probably the best example is using "*" instead of "-"

I would say we had enough fun with 42 in the last few years 

Hope Logiker isn't angry, that people are posting their current sizes,

I think it's only forbidden to post the final size or did I misunderstand?

[Prodatron]

Haha indeed. Yes you are probably right

[ZorrO]

Logiker would like more people to participate. I don't know, maybe then there would be a chance for more sponsors. And there are many people who will write some code and read that others are better because they wrote much shorter code, and will think that sending their work makes no sense because I won't win anything anyway.

Last year it was similar, he asked people not to brag on forums etc. but he didn't say that you are out of the competition if you give your result because then there would be fewer people, not more. Or maybe someone weaker would even win, because a better one will be out because he bragged about his result.

So he has a dilemma whether to throw such people out of the competition or not. Because there would be a storm of denunciations, but would it increase the number of participants?

But I see that his request was ignored this year too.

[eto]

Imho the discussion here with the progress that is shared makes it more interesting - not less. I could not care less about that competition but reading here about it and seeing how people squeeze out a byte here or there - that makes it interesting again.

Maybe it would be better to find different prize catagories to motivate more people to come up with their ideas - not only the size itself. E.g. most elegent code, most surprising solution, best newcomer.

[ZorrO]

Categories can be multiplied, e.g. each platform or language. Although in many there would be only one participant. But without sponsors they will only get congratulations.

[arnolde]

I'm at 54 bytes now, but I wonder what Logiker means by 

Also, I have to admit that this was the strangest kind of bragging: It was actually a typo, I meant 64 bytes   
Now, meanwhile I have condensed it, but I don't see 54 happening for now – maybe if I find another approach... 

[lightforce6128]

Now, meanwhile I have condensed it, but I don't see 54 happening for now – maybe if I find another approach...

I found another approach    and the problem with the prompt could also be solved. Now I cannot find anything to compress this further, but we will see. The challenge is not over.

Until now I tried 4 approaches in BASIC and 3 in assembly.

[ZorrO]

I wonder if anyone has tried chatGPT.

[Overflow]

Hi guys! I can confirm I will submit one entry. I've already spent a few days and many hours about that challenge. More fun than last year ! Since the shape is more complex, I believe there's place for more different algorithms, more optimizations and more tricks. Tonight I'm likely done with final size. 10 days to go !