The MC789 is a hex inverter, a 7404 or 7406 could be
used but the pin-out is
different
On Fri, 7 Jan 2005, Al Kossow wrote:
The only thing it has in common with a TTL inverter is
the function it performs.
RTL logic, power supply, and switching performance are NOT the same as TTL.
Al's right. For lamp drivers etc just stuff it in, but if it's
buried in the guts of high-speed ALU you're in for a project. I'm
sure many can be retrofit, but you'll need to be very adept at
reading spec sheets (and hoep that they tell the whole truth).