lotto@talcott.UUCP (Jerry Lotto) (09/08/85)
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I am interested in calculating various parameters
for a "fast" AT system but my "hardware education" is
nominal at best. So, would the hardware types out there
please take a stab at the following questions? I am knee
deep in 286 manuals and not much closer to the answers.
1) How do you calculate the maximum allowable access time
for a RAM (comparing the AT at 6 vs 10 MHz for example)
without wait states?
2) The inverse of 1 (How many wait states for a given speed
and memory?) for the type of memory subsystem in an AT.
3) What other chips in the AT are speed sensitive in the
6-10 MHz range?
4) What kinds of problems are unique to faster systems (xs
heat etc.) and what practical solutions are available?
5) What references are useful to obtain enough of an
understanding of system design to answer these questions
myself?
Thanks in advance for all replies. I will summarize
and report answers to 1-5 above if they are not posted.
--
Gerald Lotto - Harvard Chemistry Dept.
UUCP: {seismo,harpo,ihnp4,linus,allegra,ut-sally}!harvard!lhasa!lotto
ARPA: lotto@harvard.EDU
CSNET: lotto%harvard@csnet-relaysdyer@bbncc5.UUCP (Steve Dyer) (09/09/85)
> 3) What other chips in the AT are speed sensitive in the > 6-10 MHz range? > I know this isn't exactly the answer you're looking for, since it's determined solely on empirical experience, but I have been using an 18.4 mhz xtal in my AT for 3 months now, and the only problem I have is an occasional 1.2mb floppy disk error (abort, retry, ignore) from DOS. It "feels" suspiciously like the ROM BIOS uses a timing loop when poking the controller's registers, though I haven't looked at the code yet. -- /Steve Dyer {harvard,seismo}!bbnccv!bbncc5!sdyer sdyer@bbncc5.ARPA