Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!sei.cmu.edu!fs7.ece.cmu.edu!o.gp.cs.cmu.edu!andrew.cmu.edu!es2a+ From: es2a+@andrew.cmu.edu (Eric Stuyvesant) Newsgroups: comp.sys.atari.st.tech Subject: Hardware Project: RAM disk Message-ID: Date: 4 Jun 91 20:51:25 GMT Organization: Class of '91, Carnegie Mellon, Pittsburgh, PA Lines: 49 I've been considering building some sort of RAM disk for my 4 Mb 1040STE, and was wondering if anyone else out there would be similarly interested... Necessary components of said RAM disk: * use of SIMMs * support of at least 2 Mb in a minimum construction * support for different sized SIMMs (256K, 1Meg, 4Meg) * as cheap as possible I have considered several different lines of attack, including the following: * Cartridge port interface, similar to the Alpha Systems RAMdisk. This has the disadvantage of being slow, and very non-portable to non-ST systems. * Serial interface, possibly with a native CPU. This would definitely be slow, even at 19200, but would be supremely portable to non-ST systems. * SCSI interface, possibly with a native CPU. I imagine that this would be rather expensive to build, due to the cost of SCSI chipsets and an ACSI->SCSI converter board. It would, however, be useful on non-ST systems. Throughput would probably be not bad. * ACSI interface, possibly with a native CPU. This would probably be easier and cheaper to build than the SCSI version, but would be much less useful on non-STs. * CPU replacement board. Basically, replace the CPU with a CPU+memory daughterboard. Fast, but again, not useful on non-STs. I'd like to look at these possibilities in more detail, and try to get at the relative costs and strengths of each of these, then build something. Is there anyone else out there who would be interested in working on this? I'm sort of surprised that there are no commercial SCSI RAMdisks on the market. Or am I missing them? Any comments are welcome, as right now I don't have the hardware knowledge to build one of these or the software knowledge to write the drivers. -Eric Stuyvesant es2a+@andrew.cmu.edu || es2a%andrew@CMCCVB || JNET%"es2a%andrew@CMCCVB" al782@cleveland.Freenet.Edu || {uunet,harvard}!andrew.cmu.edu!es2a "To hate is to study, to study is to understand, to understand is to appreciate, to appreciate is to love." -John A. Wheeler Go MEMS!