Re: Random Dreamcast tomfoolery for Retrochallenge 2012
Mouse <[email protected]> Thu, 5 Jul 2012 17:26:09 -0400 (EDT)
| Newsgroups | gmane.os.netbsd.ports.dreamcast |
|---|---|
| Message-ID | <[email protected]> |
>> ...and if you're not afraid of a little electronics, it's easy to >> build your own. One MAX232 or equivalent and a few discretes is all >> I needed [...] > Don't use MAX232, it's for TTL voltages. MAX3232 is an equivalent > chip that can be used for CMOS voltages (just give it 3.3V as Vcc). 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. At least that's how I remember it. That circuit has been packaged up in a plastic box for quite a while now; I should probably open it and see how accurate my memory is. /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML [email protected] / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B