View source for Screen refresh rate

It is possible to set different screen refresh rates by changing some [[CRTC]] registers. With the following lines of code you can change the refresh rate to 50Hz, 60Hz or 75Hz.

== 50 Hz ==
<pre>
ld bc,&bc04
out (c),c
ld bc,&bd26
out (c),c 
ld bc,&bc05 
out (c),c 
ld bc,&bd00 
out (c),c 
ld bc,&bc07 
out (c),c 
ld bc,&bd1e 
out (c),c 
</pre>

== 60 Hz ==
<pre>
ld bc,&bc04 
out (c),c 
ld bc,&bd1f 
out (c),c 
ld bc,&bc05 
out (c),c 
ld bc,&bd06 
out (c),c 
ld bc,&bc07 
out (c),c 
ld bc,&bd1b 
out (c),c 
</pre>

== 75 Hz ==
<pre>
ld bc,&bc04 
out (c),c 
ld bc,&bd1b 
out (c),c 
ld bc,&bc05 
out (c),c 
ld bc,&bd02 
out (c),c 
ld bc,&bc07 
out (c),c 
ld bc,&bd19 
out (c),c 
</pre>

[[Category:Programming]]