Yeah, but 3090 memory was not ferrite core, was it? IIRC, it was much cheaper and more reliable. I wasn't privy to the bean-counting specifics, but the rumored cost of the LCS storage on our 360 class machines was in the neighborhood or $2.5-3M per 2MB unit. And they were real core - you could look through the glass panels and see the individual planes of wires and doughnuts. The stuff was not reliable, so we had 3 boxes in order to always have 1 available for the production ACP system. There was usually 1 in use, 1 being repaired, and 1 just out of repair that was on standby. The care and feeding of those animals was a career.
Regards, Richard Schuh > -----Original Message----- > From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] > Behalf Of Dave Jones > Sent: Sunday, October 08, 2006 7:33 AM > To: IBMVM@LISTSERV.UARK.EDU > Subject: Re: Real core > > > According to some Computer Science class notes from the mid > 1990s found > here: > http://www.google.com/url?sa=t&ct=res&cd=1&url=http%3A%2F%2Fww w.cs.utexas.edu%2Fusers%2Fdahlin%2FClasses%2FGradArch%2Fnotes%2Flec3.ps&ei=GQcpRaqwKJTowQKozoGZCw&sig=__UYn2qNuRCi6tCHeKT4QmvAKPUsw=&sig2=BLEvr7YHUEbXBBf9FMw5Ug a megabyte of 3090 memory cost $19,200. That works out to $0.018311/byte (1 MB = 1024 * 1024 bytes). DJ Gabe Goldberg wrote: > Just because I felt like doing the calculations: > > Mitre installed VM/370 on a 1/2 megabyte 370/145 (1973), upgraded to a > one megabyte 370/148 (1975 or so). I handled upgrading both processors' > memories: the 145 by 1/4 megabyte, the 148 by a full (!) megabyte. I > vaguely remember that both upgrades cost about $30,000. It also took a > while to evaluate competing vendors; in both cases we installed non-IBM > add-on memory, an interesting engineering process in itself. > > So non-core 145 memory cost $0.11444/byte and 148 memory cost > $0.02861/byte. > > Phil Smith III said: > > Ok, this is obscure to the max, but: ISTR real core costing $1/byte. > Someone else says: > "$1 a byte was extrordinarily cheap for 1971. Ferrite core was going for > up to $2 per BIT." > > Of course, he then goes on to talk about PDPs, so maybe he's talking > about core made in Maynard instead of Mexico... > > Anyway: do any of the other old-timers remember anything about this? >
