d88pt@efd.lth.se (Peter Tomaszewski) (03/16/91)
HI, I have been offered some 256Mbit rams really cheap. How do I fit them in my atari 1040STFM. Can I just solder them on top of the existing rams? What control signals should I use and where from on the pcb? ( I have 32 rams ) d88pt@efd.lth.se
es2a+@andrew.cmu.edu (Eric Stuyvesant) (03/16/91)
First, if you have access to 256 Mbit parts cheap, I'd like to pick up a few! I'll assume you mean 256 Kbit. The ST's MMU expects to see one or two banks of RAM, where each bank is 16 bits wide. So, you need to have 16 chips to fill a bank. The 520 has one bank of 256 Kbit chips, the 1040 has 2 banks of 256 Kbit chips. The Mega 2 has one bank of 1 Mbit chips, and the Mega 4 has two banks of 1 Mbit chips. The final answer is that, since you have a 1040, your machine already has both banks full of 256 Kbit chips, so you can't easily upgrade with 256 Kbit parts. You must use 1 Mbit parts to replace one or both banks, getting 2.5 Megs or 4 Megs respectively. While it is theoretically possible to do what you are attempting, it likely would wind up being more hassle than it's worth (even if you got the chips for free). Buy 1 Mbit parts to upgrade your existing machine, or better yet, an STE, and upgrade with SIMMs. Sorry, this probably isn't the answer you wanted to hear. -Eric Stuyvesant es2a+@andrew.cmu.edu || es2a%andrew@CMCCVB || JNET%"es2a%andrew@CMCCVB" al782@cleveland.Freenet.Edu Wanna buy brand new Lynx games: Blue Lghtng, Slime World, Zendocon for $22ea? Go MEMS!
wilko@idca.tds.PHILIPS.nl (W.C. Bulte) (03/18/91)
In article <1991Mar15.161629.20972@lth.se> d88pt@efd.lth.se (Peter Tomaszewski) writes: >I have been offered some 256Mbit rams really cheap. How do I fit them in OOh boy, I thought state of the art is about 16 Mbit ;-) ;-) _ ______________________________________________________________________ | / o / / _ Wilko Bulte Domain: wilko@idca.tds.philips.nl |/|/ / / /( (_) uucp : [mcsun,hp4nl]!philapd!wilko * Philips Information Systems Nederland phone: 055-432372 fax: 055-432103 ____________________________________________________________________________