From: Steve Nicklin (steve.nicklin_at_hp.com)
Date: 2003-02-20 16:17:59
Not quite! :o) CPU CLOCK SPEED: NTSC machines: 1.7897725 MHz non-NTSC machines: 1.773447 MHz Taken from: http://www.faqs.org/faqs/atari-8-bit/faq/ Getting a bit off subject a bit but I read somewhere though that an NTSC machine is ~effectively~ slower than a PAL machine because it spends more time accessing the CPU for graphics routines per second. I think it said that the PAL machine is effectively 2.2 something mHz (although not in reality). -----Original Message----- From: Christian Krüger [mailto:christian.krueger_at_pace.de] Sent: 20 February 2003 15:57 To: 'cc65_at_musoftware.de' Subject: Re: [cc65] Machines with switchable clock Hi, > the question is, does the cpu actually run faster (== > different clock, which > was the original question) or does just the videochip steal > less cycles from > the cpu (like its happening on a c64 aswell when screen is blanked) ? The last is true. So the 30% speed surplus is also not 100% correct: ANTIC (the atari display chip) 'steals' different percentages of CPU time - depending on the graphic mode used... The Atari PAL clock is allways 1.79....MHz Regards chrisker ---------------------------------------------------------------------- To unsubscribe from the list send mail to majordomo_at_musoftware.de with the string "unsubscribe cc65" in the body(!) of the mail. ---------------------------------------------------------------------- To unsubscribe from the list send mail to majordomo_at_musoftware.de with the string "unsubscribe cc65" in the body(!) of the mail.
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