Magnus Clyde Posted February 2, 2021 Share Posted February 2, 2021 Does anybody know the exact speed of the 2600 TIA? Everywhere I look it just says 1.19MHz... Quote Link to comment Share on other sites More sharing options...
+splendidnut Posted February 2, 2021 Share Posted February 2, 2021 The Atari 2600 main clock is 3.58 mhz which is fed to the TIA chip. The TIA chip divides this by 3 to provide the CPU clock running at 1.19mhz. 3.58 mhz is the frequency used by the NTSC color sub-carrier. Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted February 2, 2021 Share Posted February 2, 2021 I mean, how precise do you want it? This is the Phi0 clock signal being fed into SALLY on a 7800 while playing a 2600 game: And this is the OSC input to the TIA from the NTSC crystal on the board: Quote Link to comment Share on other sites More sharing options...
ClausB Posted February 7, 2021 Share Posted February 7, 2021 (edited) 1,193,182 Hz Edited February 7, 2021 by ClausB Quote Link to comment Share on other sites More sharing options...
+Andrew Davie Posted February 7, 2021 Share Posted February 7, 2021 20 minutes ago, ClausB said: 1,193,182 Hz I understand there are slight differences between PAL/NTSC/SECAM but I don't know the exact figures. Quote Link to comment Share on other sites More sharing options...
alex_79 Posted February 7, 2021 Share Posted February 7, 2021 NTSC TIA CLOCK = 3579545 Hz CPU CLOCK = 1193182 Hz PAL TIA CLOCK = 3546894 Hz CPU CLOCK = 1182298 Hz SECAM TIA CLOCK = 3562500 Hz CPU CLOCK = 1187500 Hz PAL-M TIA CLOCK = 3575611 Hz CPU CLOCK = 1191870 Hz 4 Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.