Ethan, I've used parts with 1976 date code at 4mhz and higher. Later part with early 80s date codes and intersils part have been over clocked to well over 8mhz and many. I have a few mid 80s part that have given no issues at 5mhz though it never occurred to me to push further. I recently got a few 1806s that clock at 8mhz without issues.
I always thought they were low but never pushed. When I did they ran a bit quite faster than expected.. Allison On Wed, Dec 18, 2019 at 3:26 AM Ethan Dicks via cctalk < cctalk@classiccmp.org> wrote: > On Wed, Dec 18, 2019 at 2:55 AM Al Kossow via cctalk > <cctalk@classiccmp.org> wrote: > > On 12/17/19 9:30 AM, Will Cooke via cctalk wrote: > > > An ad was emailed to me today with an interesting item: RCA 1802 > processors. > > > > Not a bad price, did you buy any? > > Definitely a good buy if you don't need to go faster than 3.2MHz with > +5V Vcc (I have at least one 1802 board with a socketed oscillator so > I can use an NTSC colorburst crystal (3.579545 MHz) on a divide-by-2 > to run at 1.7897725 MHz for use with a CDP1861 "Pixie" video chip, or > swap that out for a 5Mhz or 6Mhz crystal for faster operation). The > CDP1802BC can go up to 5MHz with a 10MHz oscillator on the same board. > > > Were they actually RCA-branded parts from the 70's? > > Curious to know too but I'd expect a Harris part just because of > general availability. > > -ethan >
