Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!sdd.hp.com!wuarchive!uunet!mcsun!ukc!mucs!p4.cs.man.ac.uk!gilbertd From: gilbertd@p4.cs.man.ac.uk (Dave Gilbert) Newsgroups: comp.sys.acorn Subject: Re: ROM speed [was: various MEMCs] Message-ID: Date: 7 May 91 07:41:52 GMT References: <1991May6.015432.5020@alzabo.ocunix.on.ca> Sender: news@cs.man.ac.uk Lines: 27 OK - lets start with different MEMCs. The one in the original A310's, and A440's was the MEMC 1 - the story I was told was that it had a bug somewhere, and a bit of logic on the PCB was needed to kludge it into working - this resulted in a degredation of speed by about 10% - when they finaly bought out the A400/1 series the MEMC1a was born - fixing the original problem and so we could all run that little bit faster - the difference is easily noticable - I use both a 310 and a 420/1 - the speed is noticably different on some of the programs I use. There is a rumour that there is a MEMC 2 - which is supposed to be able to have varying page sizes - a lot better really. As for ROM speeds - well all us people who don't have A540's and R260's run our ARM and memory at 8MHz - but the ROMS aren't guarenteed to run at 8MHz, only 4MHz - so when you access your ROMS the MEMC slows everything down to 4MHz and then up again when you access everything else - hence the RMFASTER command which shifts modules from ROM to RAM and these little programs which tell the MEMC that your ROMS can run faster. I would really be grateful if someone could explain why after the semi conductor industry has made fast RAM possible at a reasonable price why ROMS are so difficult. Dave -- ------------------------------------------------------------------------------- - Dave Gilbert - gilbertd@p4.cs.man.ac.uk - The MTBF of a piece of equipment - - G7FHJ@GB7NWP - is inversly proportional to its - ------------------------------------------- importance -