horizontal scrolling in basic

Shaun_B
Posts: 392
Joined: Wed Apr 22, 2009 10:22 am

Re: horizontal scrolling in basic

Post by Shaun_B » Mon Aug 14, 2017 8:12 pm

What's happening with the 23606 poke?

Thanks,

Shaun

dr beep
Posts: 1060
Joined: Thu Jun 16, 2011 8:35 am
Location: Boxmeer

Re: horizontal scrolling in basic

Post by dr beep » Tue Aug 15, 2017 9:43 am

Since we are talking POKING 23606 and own development of characterset and Shaun Bebbington replying....


Define your own "characterset" (this can be UDG too, but in characterrange) and make it 10 characters/udg. Make the 11th the same as the first.

Now by poking 23606 from start to start+80 and printing a character on same spot after each poke you get the rolling effect
from a fruitmachine. Since chr11 is the same as chr1 you will get the rollaround effect.
To add more visible chr on the roll: add print chr-1 above and chr+1 below.

Shaun_B
Posts: 392
Joined: Wed Apr 22, 2009 10:22 am

Re: horizontal scrolling in basic

Post by Shaun_B » Tue Aug 15, 2017 10:28 am

Thanks Dr Beep - I've actually thought of a way to improve my advanced** fruit machine simulator for 1K ;-)





** Might not be so advanced

User avatar
1024MAK
Posts: 1857
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: horizontal scrolling in basic

Post by 1024MAK » Tue Aug 15, 2017 12:56 pm

Shaun_B wrote:
Mon Aug 14, 2017 8:12 pm
What's happening with the 23606 poke?
By increasing the value by 8, you move the start point of the look up to the pattern data so that BASIC prints the image for the next character pattern to the screen. So for the first increase, when 'A' is printed, the system uses the pattern for letter 'B' instead.

Mark

Post Reply