Re: Random Dreamcast tomfoolery for Retrochallenge 2012
Marcus Comstedt <[email protected]> Thu, 05 Jul 2012 23:52:32 +0200
| Newsgroups | gmane.os.netbsd.ports.dreamcast |
|---|---|
| Message-ID | <[email protected]> |
Mouse <[email protected]> writes: > I actually did use a MAX232, at least partially because I had it on > hand. The "few discretes" level-shifted the voltages to the 3.3V the > DC expects. I didn't mind doing so, because in my experience (and it > turned out to be so here too), a MAX232 always gets the levels > backwards, so they need inverting. I usually use discretes for this > (occasionally an '04); it turned out to be no big deal to use the same > transistors for both level-shifting and inverting. Ok, I figured the "few discretes" referred to the 4 caps needed for the voltage pump. With a 3232 or 3222 you don't need either inverters or level shifters, just the chip itself and 4 caps. // Marcus