Re: 14MHz 65816??

[nathan@visi.com (Nathan Mates)]

In article <4ut0ev$r24@News.Dal.Ca>,
Tony Cianfaglione <tony@ccn.cs.dal.ca> wrote:
>   I have been in contact with Western Digital regarding their 14 MHz 
>65816 chip which they tell me fits onto the accelerator cards such as the 
>TransWarp GS or Zip GS.  They were not sure if it would replace the stock 
>GS chip that plugs into the motherboard, which is what I want to do.  I 
>find the various accelerator cards too buggy to rely on.

   You cannot drop a faster 65816 into the motherboard and expect it
to run any faster-- the timing signals on the motherboard are locked
at the 2.8Mhz speed, and changing that would require a motherboard
redesign. Running a chip slower than its rated speed is fine-- it will
just run at the slower speed. (Well, up to a point... if you ran a
658116 at maybe 1/32 or 1/64 of its rated speed, it'd probably start
having a bad day)

   That is why you need the accelerator cards-- a place to run a
faster 65816, an oscillator for the faster 65816, and the logic needed
to interface a fast 65816 to the GS motherboard at 2.8Mhz. 

>   They keep crashing in the middle of vital projects and I'm forced to 
>disable the cards and run at the native speed.

   What speeds? Some people say that the bleeding edge speeds (>12Mhz
or so) can be flakey, but reducing the speed one notch on the ZipGS
control panel made it run fine. My Zip 9/32 is rock solid (the only
problem with it is that the cache access LED has never worked, but as
I keep the case on my GS, I don't care about that). Also, the default
ZIP CDev is buggy as hell, and should not be used. The FTA's ZIP
CDA is fine as long as you don't try and run it under ProDOS 8.

   Have you also considered that it's a software crash caused by the
loading of the inits/das to control them?  In my experience, just
adding removing, or changing the load order of things can cause memory
trashing caused by another program to suddenly step on 'critical'
areas of ram or more 'useless' areas. 

Nathan Mates

--
<*> Nathan Mates http://www.visi.com/~nathan/      <*>
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