EDO RAM on A4000 mobo?!

[Jose]

Hey. I though EDO didsn't work, but from the more than 10 different SIMM modules I've tried (borrowed from computer stores) just a few ones work, and they're mostly EDO Simms! Can someone confirm this? Am I at risk to get memory corruption if I continue using them? I guess a good program to test mem would be adequate, can you recommendo a demmanding one?
Cheers dudes :-D

[Hyperspeed]

I wouldn't reccomend EDO.

EDO = Extended Data Out, this means data is stored longer than FPM
ready for the CPU to pick up a 2nd time.

This is not how an expert would explain it but I'm giving my own
understanding of it.

I think the difference in technology creates problems for older
machines, most notably Apple Macs (a few of which have been known to
be damaged by EDO in particular).

I've heard from a few people that they would never use EDO again on
their Phase5 Blizzard accelerators which often date to the mid-90's.
What hope then does an A4000 have of 100% reliable performance using
EDO designed for P75->P120 machines?

The newer EDO is more incompatible still and some DCE hardware such as
the CD32's SX32-Pro actually supported it, albeit with a special
jumper to notify the accelerator of a 50ns timing.

EDO is a lot more common but I would chose FPM every time. The best
type of memory for Amiga in my opinion is single-sided FPM, 2k/4k
refresh and non-composite (made up of as little DRAM chips as
possible).

:-)

[Jose]

Boards actually damaged by EDO?!:-o  Can someone confirm?
For reliability I guess I could make a few tests, though the memory test programs I found in Aminet don't seem to be very good.  

By the way, I'm getting 14.xx MIPS in SysInfo, is this normal or could it have something to do with the memory used? I have a 3640 board at 25mhz... I'm asking this cause I seem to remember stock 040 A4000's had around 19.5 MIPs or something...

[bloodline]

That's poop!

As far as an Amiga is concerned EDO is FPM. I've used loads (~30) of different SIMMs in my Amigas and they were all EDO, and I've never once had a single problem.

[Ilwrath]

As far as I know, EDO shouldn't cause any damage.  The extended information is just ignored by Amiga, and it functions in FPM mode.  I don't remember if I have EDO in any Amiga at the moment, but I know I've used it in the past.

I have heard rumors that, somewhere, a Mac was damaged by EDO RAM.  I wrote this off as probable damage caused by someone using a mallet to install a SIMM module.  This is not the recommended procedure.  ;-)

[odin]

Mac users and technicalities....bad combination. Hey Apple didn't invent the single button mouse for nothing :-D.

[Jose]

..."Apple didn't invent the single button mouse for nothing .."

:lol:

[inewham]

I'm happily using a mix of EDO and FPM in my A4000's and have been for quite a long while. FWIW I've never had any problems.