Geoffrey_Welsh@isishq.UUCP (Geoffrey Welsh) (06/28/88)
> From: aic@s.cc.purdue.edu (George A. Basar) > Date: 15 Jun 88 15:25:14 GMT > Message-ID: <3187@s.cc.purdue.edu> > > I know this has been here before, but could someone post a circuit > description or reference a computer magazine article for a homebrew > C64-RS232 interface. An article on building a homebrew RS-232 interface appeared in the Transactor not long ago. Anyway, you'll need voltage doublers using the AC lines of the user port to generate +/- 10V to supply the RS-232 driver. I sugegst using isolation capacitors between the user port AC lines and the voltage doublers because the AC lines are NOT completely isolated from ground. Use a 1488 driver and a 1489 receiver. They provide 4 in and 4 out lines, which should be sufficient for almost any applications. If you want more specific info, send netmail to: {...!}watmath!isishq!Geoffrey_Welsh > Also, does anyone have a source for the 24 pin card edge > connectors You mean the 2 * 22 for the cartridge port? Vector part #3795 is a perf board (just under 3" by 4") with correctly spaced pads. #3795-1 includes interspaced power and ground busses if all you want to do is mount a few ICs (I found the layout to be a bit restrictive since I like to put all sortsa stuff on the thing - I'm presently wiring an 8250 UART while contributing support drivers for a terminal program). Geoff {allegra|decvax|utzoo|clyde|etc.!}watmath!isishq!Geoffrey_Welsh "Who needs a disclaimer? No one pays attention to me anyway!"