Re: Please Help me Somebody with DEMUX Gate

Posted by WBahn on Jun 18, 2019; 2:52pm
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/Please-Help-me-Somebody-with-DEMUX-Gate-tp4033175p4033309.html

michael1978 wrote

HI,,
Wbhan do you think maybe to make DAC after to generate hsync a vhsync signal for video?

I'm not exactly sure what you mean here.

Are you trying to get color, or just monochrome to match the basic Hack hardware?

Generally a simple resistive voltage divider is sufficient to get an acceptable signal level and if you only want two bits of color depth per color a two-resistor network works fine. Three-bits is also pretty easy to achieve. More than that and you probably want to start considering a DAC.

I ran across this which has some useful info on timing and signal levels:

https://javiervalcarce.eu/html/vga-signal-format-timming-specs-en.html