[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: WDC 65C02
- Subject: Re: WDC 65C02
- From: Linards Ticmanis <ticmanis@gmx.de>
- Date: Sat, 25 Mar 2006 01:27:25 +0100
- In-reply-to: <dLIUf.550$t22.534@dukeread08>
- Newsgroups: comp.sys.apple2, comp.sys.atari.8bit
- Organization: Arcor
- References: <dLIUf.550$t22.534@dukeread08>
- User-agent: Mozilla Thunderbird 1.0.6 (X11/20050715)
- Xref: g2news1.google.com comp.sys.apple2:5824 comp.sys.atari.8bit:2701
Jack Tseng wrote:
Can MOS 6502 be replaced with WDC65C02 Microprocessor? The WDC can fit with
Atari 8bit family and Apple II family...
Yes and no.
You will lose compatibility with programs that use the 6502's "illegal"
opcodes. That's less of a problem with Apples since the company switched
to 65C02 by itself before too many programs with the illegal opcodes
were on the market.
For other system architectures that stayed with the NMOS 6502's longer
and/or used lots of cycle-counted raster beam racing code, the problem
gets bigger. Examples would be the Commodore and Atari computers and
consoles.
And of course there is the problem that other people mentioned already:
Those systems that use NMOS 6502 *derivatives* (such as 6502B, 6507,
6510 etc.) can't use the 65C02 chips without some extra circuitry.
--
Linards Ticmanis
- References:
- WDC 65C02
- From: "Jack Tseng" <tseng4@hotmail.com>