ZX Computings - OpenLibra
ZX Computings - OpenLibra
ZX Computings - OpenLibra
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70<br />
Hypno<br />
Tim Johns from<br />
Birmingham has<br />
J£22 u ?? d a routine<br />
which shows off the<br />
graphics capability of<br />
the <strong>ZX</strong>81 to good<br />
effect creating a<br />
constantly changing<br />
square pattern on the<br />
TV screen.<br />
This program, instead of using<br />
^T° b V i ° U S of<br />
ruiNi, makes use of POKE<br />
putting the code values of the j<br />
characters directly into the<br />
display file, the start of which is<br />
identified in line 10. By doing<br />
this, you get a 24 x 24 display<br />
whereas using PRINT restricts<br />
you to 22 lines.<br />
The style' of each frame of<br />
the pattern is established in<br />
fl?? S t°,? nd 50 ' P ,us 70 ^<br />
BO. which set the probability of<br />
the characters chosen being<br />
changed within each frame<br />
and hence the 'uniformity or<br />
variety' of pattern of the<br />
frame, and also the probability<br />
of the characters being aligned<br />
in or out of phase.<br />
• r - r - . i ,<br />
I ^<br />
•: • " ? ••'<br />
ft V » l 0Jr. . J<br />
<strong>ZX</strong> COMPUTING SUMMER<br />
<strong>ZX</strong>
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