[EFI68k] new release and group survey

[John S Gwynne]

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   In message <9501271546.AA26327 at ivan.gallium.com> , you write:
 
| 1) Will the MAX791 and KM681000L allow the contents of the SRAM to be retaine
| d
|    over power off? How much current will be drawn to keep the SRAM contents
|    alive? (Mine would go in a boat, and drain may be a problem if the boat
|    isn't run for week or two.)

yes, it will store RAM and continue to keep time. I believe
I measured less than 100uA at room temp. This should not be a
problem for a car/boat battery but I would like to see a
separate battery. I believe nicad batteries have "problems"
at temperatures below freezing (??? is this true ???) and I
have not tried to find the temperature range of a lithium
battery. I would love to find a battery that would recharge
while the engine was running, have a temperature range
compatible with the car's environment, and be about the size
of a quarter (in the 2-4.5V range). Any ideas? 

| 2) Downloading 256KB or code at 9600 baud will take two minutes. Is there any
|    way to speed this up? (i.e. much higher baud rate, or parallel interface)

(256*1024)/(9600/10)/60=4.5 minutes (binary transfer) ???

I've been running at 38400 (limited by the host) but am
also transferring s-records. That's about 1920 bytes/sec. I've
heard of 16550's running at over 100k baud.  I have not
given parallel port transfer much thought since I don't
believe the parallel port on an SGI Indigo is bidirectional :(.
The C library tends to be about 24k (mostly stdio stuff)
while the C++ library is on the order of 80k. RTEMS is
suppose to be about 16k. The EFI software should be much
less complicated than all of these... maybe 12k (blind
guess) with all the options for a total of 24+16+12=52k.
I hope to use a good portion of RAM as a "data recorder".


                                       John S Gwynne
                                          Gwynne.1 at osu.edu
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