Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!samsung!munnari.oz.au!metro!macuni!sunb!ifarqhar From: ifarqhar@sunb.mqcc.mq.oz.au (Ian Farquhar) Newsgroups: comp.sys.amiga.misc Subject: Re: Nintendo Emulator? Message-ID: <1444@macuni.mqcc.mq.oz> Date: 9 Apr 91 00:48:10 GMT References: <22722@know.pws.bull.com> Sender: news@macuni.mqcc.mq.oz Organization: Macquarie University, Sydney, Australia. Lines: 42 In article kuch@reed.bitnet (Jerry Kuch) writes: >I took a Nintendo NES (or whatever the acronym is) apart once and was less >than impressed. The CPU is not a 68000...it's an old MOS 6502! The >Commodore-made chip that went in the Apple ][, the Atari 8-bits, the VIC and >the C64. No, not quite. Nintendo re-engineered the 6502, removing some operations and optimising others. It is not a stock-standard 6502 by any means. >There are a couple of custom chips which I believe only Nintendo has the >access too. From memory, there is the CPU, the PPU (Picture Processing Unit), the CIC (lockout chip), and a couple of TTL gates, plus 2K SRAM for the CPU, and 2K SRAM for the PPU. Nintendo, as usual, made heavy use of custom silicon. >I believe the specs are something like 280 x 160 screen resolution, >on the order of 50 colors (maximum, a real value of 24 wouldn't be too >surprising), 56 colors. The carts are bankswitched, and must include a CIC chip. If the CIC is not present, the system continually resets itself. Of course, this is easily circumvented, as the CIC serves no other useful purpose and can be disregarded in a clone. The PPU would be easy to clone. The major hassle would be Ninetndo's legal department. Even people who have cloned the CIC chip, or produced games based on a cute little workaround that disabled the CIC chip (Nintendo recently plugged that hole), have been sued, and Nintendo's legal department is something you do not want to tackle. However, as many people have pointed out, the Nintendo is just too cheap to bother cloning. I doubt that you could manage to do it in software, and the hardware would just cost too much to make it economically feasable. -- Ian Farquhar Phone : + 61 2 805-9400 Office of Computing Services Fax : + 61 2 805-7433 Macquarie University NSW 2109 Also : + 61 2 805-7420 Australia EMail : ifarqhar@suna.mqcc.mq.oz.au