🚀 go-pugleaf

Mark Griffith writes:
>
>Ricky,
>
>> Furthermore, I don't think anyone is going to get the system to start faster
>> than 16MHz as the Meg used at boot up is 80ns and is controlled via the
>> VSC (and more time)  but once the the system has switched to the expansion
>> RAM things can be spead up quite abit.  I have gotten shamu up to 20 MHz
>> (well, 'till that 80ns simm got hot! had a 70 and a 80 in there <grin>)
>
>This is not really correct.  A 3 meg or above system always uses the
>expansion RAM...the 1 meg on the mother board is used for video only.
>That's what the jumper does, it moves the video RAM up above the 8 Meg
>limit.

It was my understanding (from the Tech Manual) that the system always starts
with the Video RAM at $00000000 and then it switches it out after the vector
checks (or what ever)  For that reason, you had to leave the first $1400 bytes
or so of that memory free in the init module if you ever wanted to use the
system debugger (as I did)

>You won't get much more than 16 Mhz reliably with 80ns SIMMs.  I put 60ns
>SIMMs in mine and had it work quite well at 20 Mhz, but then I have a 25 Mhz
>rated 68340.  All the production units have 16 Mhz CPUs.  You're pushing the
>CPU, not the SIMMs.

Well, that suckes _BIG TIME_!  And as I have the very first production board,
it probably has a bug or two.  As a matter of fact, the CPU looks kind of
like a human and an iron have been in there! <grin>  Now to economics,
what is the proce difference for the 25Mhz and 16Mhz ratings?

Right now, I'm not really sure if you get a 300$ proformance increase.  Info
is building however and it is indeed nice to see the thing beat a 486DX50!
(We had a drag raced "locked loop to 1 million"  time reports zero, linux
reports .02!! Ha! Stick that in your pipe (@15.87 MHz)

>
>/\/\ark
>

PS: Send that 4meg upgrade stuff on down the pike... I want to run the
canyon flicker! (2+ meg)

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