Path: utzoo!attcan!telly!ziebmef!timg From: timg@ziebmef.uucp (Tim Grantham) Newsgroups: comp.sys.amiga.tech Subject: Re: lucas without 6888x Message-ID: <1989Jul22.100937.13982@ziebmef.uucp> Date: 22 Jul 89 14:09:36 GMT Reply-To: timg@ziebmef.UUCP (Tim Grantham) Organization: Ziebmef Public Access Unix, Toronto, Ontario Lines: 32 In article <643@becker.UUCP> douglee@becker.UUCP (Doug Lee) writes: >You will have a problem running the Francis board this fast unless you get >REAL fast ram chips. Even then it might not work. The problem is that above >16 Mhz or so, you have to insert extra wait states (wasted clock cycles) >because the ram cannot keep up with the CPU. I don't yet have my own Francis, >but according to Brad Fowles, the designer, the system is faster running at >16 Mhz with 1 wait state ram than at 20 with 2 wait states. You MAY get it to >work at 20 with one wait state as I think some people have had limited success >at this. > ><<>> >douglee@becker I have been running my Frances/Lucas board at 20 MHz with one wait state for a while now. The crucial factors in getting this to work for me was not the U9 chip -- they were one, trying different clocks until I found one that worked, and two, always letting the computer warm up for at least half an hour before attempting to do anything with it. Actually, I simply don't turn it off now. The U9 chip I used is a TI SN7474, the clock is a MTRON make. Mind you, I don't have a bus terminator and I don't have anything on the expansion bus. Tim. P.S. I'm using Siemens 70 nsec. memory chips. -- timg@ziebmef.UUCP {uunet!mnetor!lsuc,utgpu}!ncrcan!ziebmef!timg ------------------------------------------------------------------------------- How many Amiga users does it take to change a light bulb?