Lode Runner on the ZX81?

Any discussions related to the creation of new hardware or software for the ZX80 or ZX81
dr beep
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Re: Lode Runner on the ZX81?

Post by dr beep » Thu May 04, 2017 1:00 pm

Almost there....
An issue with the ladders.
screentest.png
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Getting closer...
screentest2.png
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dasteph
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Re: Lode Runner on the ZX81?

Post by dasteph » Thu May 04, 2017 1:08 pm

Agree that we can get some nice effects without going to Hires.

See 2 files in the tar of the lode runner running across the screen. One version is a Hires test graphic, and the other a quick and dirty test of something similar in standard ZX81 charaters.

http://dasteph.com/cgi/zx81/files/tmp/runner.tar.gz

For low res, it all depends on how fast the character draws happen, you can generate the feeling of a 'man' running using the correct characters.

dr beep
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Re: Lode Runner on the ZX81?

Post by dr beep » Thu May 04, 2017 1:33 pm

Next screen.... the O was a 0.
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dr beep
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Re: Lode Runner on the ZX81?

Post by dr beep » Thu May 04, 2017 1:52 pm

Yes....
temporary player as hardbrick... but ready.

Level in 83 bytes.... Still to add 2 bytes for player and perhaps a byte for number of bytes for fast access next level.
screentest4.png
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edit: player as player code gives also correct screen, but without player on screen.. therefore 2 extra bytes.

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dasteph
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Re: Lode Runner on the ZX81?

Post by dasteph » Thu May 04, 2017 2:03 pm

Very nice, a saving of aprox 20 bytes on the scheme I had in mind originally. Or to put it a better way, room for an extra level in every 4 over the original.

dr beep
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Re: Lode Runner on the ZX81?

Post by dr beep » Thu May 04, 2017 2:40 pm

I added a dotted border to simply test out of screen.

dr beep
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Re: Lode Runner on the ZX81?

Post by dr beep » Thu May 04, 2017 2:48 pm

dasteph wrote:
Thu May 04, 2017 2:03 pm
Very nice, a saving of aprox 20 bytes on the scheme I had in mind originally. Or to put it a better way, room for an extra level in every 4 over the original.
Are the original levels somewhere available in ASCII-format??

dr beep
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Re: Lode Runner on the ZX81?

Post by dr beep » Thu May 04, 2017 2:53 pm

dasteph wrote:
Thu May 04, 2017 12:16 pm
To print 109 to the screen without getting "?", you need to poke it to the Dfile.

05 rem print to the first character space on the screen
10 poke peek 16396+peek 16396*256+1,109
20 print peek (peek 16396+peek 16396*256+1)

The idea would be to poke the entire active level to the Dfile.
The writing to the screen is entirely done with POKE!
Screen is full size and is directly accessed by the program.
So 109 should work.

dr beep
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Re: Lode Runner on the ZX81?

Post by dr beep » Thu May 04, 2017 2:55 pm

dasteph wrote:
Thu May 04, 2017 2:03 pm
Very nice, a saving of aprox 20 bytes on the scheme I had in mind originally. Or to put it a better way, room for an extra level in every 4 over the original.
I store a single character in a nibble. That's where the extra positions are won.
Also I can store 18 repeating characters in a full byte. First line has 18 repeats already.
This saves another byte when over 16 repeats but less than 19.

sirmorris
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Re: Lode Runner on the ZX81?

Post by sirmorris » Thu May 04, 2017 4:01 pm

Looking good. I like the lo-res aesthetic.

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