Vintage Computing Christmas Challenge 2023

[g0blinish]

rules

[Dr beep]

I have a program ready to sent in.

[uglifruit]

Me too, and I've thoroughly enjoyed thinking about it - and approaching constructing the pattern in different ways and seeing which I found most efficient. I've also been cursing the lack of modulo in ZX Speccy BASIC which I think would have helped. I still have a few more approaches I might explore. And I'll be very interested to see what other approaches people take.

Ii's interesting to be judged primarily on size of "source code", given that's a plain text file with the BASIC in it. So using NOT PI instead of 0 (as I'd do if I was making minimal size) is a massive no-no.

[TMD2003]

Me too, and I've thoroughly enjoyed thinking about it - and approaching constructing the pattern in different ways and seeing which I found most efficient. I've also been cursing the lack of modulo in ZX Speccy BASIC which I think would have helped. I still have a few more approaches I might explore. And I'll be very interested to see what other approaches people take.

I can think of a few with-modulo BASICs that are all relevant to us in some way: Next BASIC, QL SuperBASIC... and BBC BASIC on the Z88.

Go for it!

[Dr beep]

Program sent in!

[MustardTiger]

I've got a BASIC one and a machine code one. Both use completely different solutions.

[Dr beep]

5 minutes after sending in I found a byte won, so now 1 byte below a round number.
Previous version had a round number.

[Dr beep]

I've got a BASIC one and a machine code one. Both use completely different solutions.

Did you sent them in?

[MustardTiger]

Did you sent them in?

Not yet.

[MustardTiger]

@Dr beep I just saw your entry for last year on the results video, 29 bytes! Crazy!

[Dr beep]

@Dr beep I just saw your entry for last year on the results video, 29 bytes! Crazy!

after the contest I got to 25 for ZX81 and 26 for ZX Spectrum

[Dr beep]

I already sent in 4 programs, every time a bit shorter.

[Dr beep]

@Dr beep I just saw your entry for last year on the results video, 29 bytes! Crazy!

Hope to amaze you this year once again.
I can't say anything, wait another week.

[MustardTiger]

Hope to amaze you this year once again.
I can't say anything, wait another week.

I'm looking forward to see the results. I've sent in an entry which I'm happy with. I ended up making an assembler version of my Basic attempt.

[flange]

Just for a giggle I did it in Forth-79 (ZX81) but I don't it think would be as short as Johan's or any other offerings so will leave it and see where mine would have come in the scheme of things.

[Dr beep]

I'm looking forward to see the results. I've sent in an entry which I'm happy with. I ended up making an assembler version of my Basic attempt.

I stated in my coding course that everybody should code assembler since this is shorter.
So was your code shorter than BASIC?

[MustardTiger]

I stated in my coding course that everybody should code assembler since this is shorter.
So was your code shorter than BASIC?

My assembler one is 30% the size of the BASIC one. I do most of my speccy programming in assembler, my BASIC version of this was just to get my algorithm working.

[Dr beep]

Woke up this night with a wild idea.... out of bed to test... didn't work.
Hour later wope up again... another idea... out of bed.... did work, so another byte off of the code.

[g0blinish]

results and entries https://drive.google.com/drive/folders/ ... FJ0uEKuJel

[uglifruit]

Presentation here: https://www.youtube.com/watch?v=RGv2u6epVTY&feature=youtu.be

I managed to forget to send my entry, misread the deadline. D'oh.

Code: Select all

1 CLS:FOR a=3 to 18 STEP 6:for b=0 to 35:PRINT AT FN d(b+a),FN d(b);"*":NEXT b:NEXT a:DEF FN d(x)=x-(x>18)*2*(x-18)

Was quite pleased with it as well! (116 characters, including the carriage return)


And was pleased to use the fact Spectrum basic can print at negative co-ordinates to save me an ABS. It's obviously my thing. And a DEF FN

[g0blinish]

still imressing on winter - 23bytes

[ParadigmShifter]

I'm just shocked that Dr. Beep did not win

[flange]

I did it at home for fun and managed 173 bytes using Toddy Forth79 (ZX81.)
Beat the Ace Forth though which was pleasing.

[Dr beep]

I'm just shocked that Dr. Beep did not win

If you compare our code you will see that 99% is the same.
In my defense: I did it alone!

[Dr beep]

I'm just shocked that Dr. Beep did not win

His single byte less is where I was looking for all the time.
I had the idea another byte could come off, but I didn't see it in time.

The ADD HL,BC trick was indeed the way to get H in the right value.
I did make my own 23 bytes version AFTER seeing the winner trying to make it 22

Code: Select all

	org 	55570			

; A=18
; C=18
	ld	e,a
	rrca

	add	hl,bc	; ATTEMPT TO SET H AND L BUT H ONLY SUCCEEDS NO WINS!
				
l1	ld	b,a
	call 	#200a			; PRINT AT C,B!!!

	ld	a,"*"
	rst	16			; PRINT "*"

	ld	a,e			; mirror X-coordinate
	sub	b			; A now 18-X

	dec	d			; repeat even number of times
	jr	nz,l1			; so at the end A holds start X

	sub	h			; go to next X-coordinate
	jr	nc,l1			; test out of screen

	adc	a,e			; if so repair in screen and move 1 position up
	dec	c
	ret	m
	jr	l1