Newsgroups: comp.sys.apple2 Path: news.weeg.uiowa.edu!news.uiowa.edu!hobbes.physics.uiowa.edu!zaphod.mps.ohio-state.edu!cs.utexas.edu!uunet!munnari.oz.au!constellation!darkside!okcforum.osrhe.edu!dsdd From: dsdd@okcforum.osrhe.edu (Roy Barrett) Subject: Re: ZipGS upgrading Message-ID: Sender: news@darkside.osrhe.uoknor.edu Nntp-Posting-Host: okcforum.osrhe.edu Organization: Oklahoma City... blech X-Newsreader: TIN [version 1.1 PL9] References: <1993Apr7.162038.19450@cas.org> Date: Fri, 9 Apr 1993 15:16:09 GMT Lines: 87 To Upgrade a ZipGS by Roy Barrett (this was typed online, not pre-prepared. :) ----------------------------------------------------------- DISCLAIMER: ***READ ME READ ME READ ME*** I will *NOT* be held responsible for any damages, caused by the user, the Zip, or the GS, to any other hardware, or to any legal action brought against me. Use this info AT YOUR OWN RISK. ----------------------------------------------------------- Parts : WDC 65816-14 SRAM Cache if desired. Depending on Speed and Size. 50, 55, or 60 MHz Oscillator. Select 4 times the speed you're wanting to go. ----------------------------------------------------------- WDC 65816-14: Western Design Center 1-602-962-4545 SRAM : Microprocessors Unlimited 1-918-267-4961 Narrow Sockets 41256A20P (32kx8 SRAM, 20 ns, DIP package) ($10.75 a piece. 4 required for 64k @ 20ns) Wide Sockets CXK58258P-35 (32kx8 SRAM, 35ns, DIP package) ($14.00 a piece. 4 required for 64k @ 20ns) Oscillator : Digi-Key Corporation 1-800-Digi-Key (Canada too) Part numbers are: Mhz Part # Price ------ ------- ----- 32 SE1101 3.60 33.33 SE1102 3.60 36 SE1103 3.60 40 SE1104 3.60 42 SE1105 3.60 46 SE1106 3.60 48 SE1107 3.60 50 SE1108 3.60 55 SE1109 3.60 60 SE1110 3.75 ----------------------------------------------------------- Installation: Once you get all of your materials, remove the old 65816 from your ZipGS. Replace this with the 816-14. You should use a special chip puller designed for this. You could also use a paperclip and pull it out, but don't apply too much force, it could break the 816. Once that is done, you will need to desolder the old Oscillator. there are two types of Oscillators now on Zips. 4-pin, which is the somewhat older one, and the new 2-pin oscillators. It doesn't matter which one, but desolder that oscillator and pull it out. Now take your new oscillator and put it in the spot where the old 4-pin oscillator used to be. If you look at the diagram printed on the board, you should be able to easily tell. Make CERTAIN that the notch is pointing towards the top of the board. If you ordered the wide chips, and have wide sockets, go ahead and just pop them in. Same goes for the narrow sockets. If they differ in size, you will need to order new sockets from Digi-Key and solder them in. Do NOT use the .300 to .600 mil socket adapters, they have not been tested, and they do not work for me. ----------------------------------------------------------- any questions, please mail: dsdd@okcforum.osrhe.edu (or if that bounces, chances are it won't, use...) root@outbound.core.fnet.org -----------------------------------------------------------