Hello there!
Well I think like the double-sided thing, refresh is another red
herring.
There are 4x types of refresh:
-----------------------------
1k = fastest but eats power (not good for laptop batteries!)
2k = fast and needs power
4k = slow but not much power needed
8k = slower but very power efficient (usually EDO)
I would say 2k or 4k is a good average for Amigas as it doesn't take
any extremes then which could irritate your accelerator.
I think you are correct in stating all EDO is 60ns minimum. You do see
the occasional 50ns EDO and I think the CD32's SX32-Pro accelerator
has a jumper to allow this.
However I wouldn't like to try this on older 1996 Phase 5 boards. Not
even the 1260.
Phase5 did say that EDO was compatible but EDO evolved quite a bit
before SDRAM came along and some EDO likes to be placed in pairs in
order to receive the full memory amount. This happens a lot with laser
printer memory, sampler memory and server memory.
If you like the look of a SIMM then type out the code in this forum
and I will translate what it means for you to help you decide if it's
a nice one for your Amiga.
As is mentioned below, I too have a problem with a capacitor or
something getting in the way so I cannot use a double-sided SIMM on my
Blizzard SCSI-IV kit. This is possibly unique to my v8.5 DCE model but
it means now that I can only use a maximum of 2x 64mb SIMMs (since the
'060 card's CPU forces away any double-sided SIMM due to the socket
angle.
Another thing Blizzard owners need to consider is that if you use 2x
SIMMs then your card will run them at 70ns, use just 1x and you will
whizz by on 60ns.
I'm shooting myself in the foot by using 2x 16mb FPMs instead of 1x
32mb SIMM, but I haven't seen any difference in speed between 70ns and
60ns in SysInfo or in practical use.
:-)
Oh and I forget, clean your SIMM, Zorro, Trapdoor etc. connectors with
Isopropyl Alcohol to ensure that no finger grease or oxidisa