Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!olivea!apple!agate!ucbvax!gnh-starport.cts.com!whitewolf From: whitewolf@gnh-starport.cts.com (Tae Song) Newsgroups: comp.sys.apple2 Subject: Re: Zip Chip GSX Message-ID: Date: 1 Dec 90 10:33:45 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 23 X-Unparsable-Date: Fri Nov 30 90 at 23:11:01 (EST) News from Zip Chip... Fastest 65816 that WDC makes runs at about 9.8Mhz with the standard 5 volts. The 65816s at high speeds have problems with some instructions like SEP, which take up more cycles than alloted to them. Upgrading from the standard 8Kx8 chips to 32Kx8 chips. The 32Kx8 SRAM are labelled 62256... fastest I've found them was 100ns. Now, 100ns work only up to maybe 14Mhz... for 20Mhz you'd need 40 or so ns SRAMs. The 62256, BTW you can order from IC Express (I think that's the company) for about $6.50. You might be able to queezes out maybe a couple point some Mhz more out just changing crystals... and maybe another 1Mhz or little more with a 6 or so volts... I've been wondering lately, though about the ICE CUBE units for 486s. These things attach on top of the 486s and let them run at 50Mhz... turns the temperature to 0 degrees celisus, I beleive... a heat sink would maybe worth looking into for the 65816... Whatever happened to ASIC Enterprises?!? Where's that 20Mhz 65816, when you need it!!! Uh oh, NOW what...