Re: Alltech Electronics-- Accelerator Upgrade

[Rubywand <rubywand@swbell.net>]

Advanced Integration Designs Aust. writes ...
> 
> i finally got a hold of someone at alltech electronics, 3 weeks after ordering the
> items..they already billed my card..anyway, the package was sitting there
> and they told me mail goes out every couple of weeks and
> it wont go out until the 21st of february!..do you believe that crap? ....
> ill have to call in the morning and *beg* them to send it fedex .. ....

     Ask for Tony Diaz. He may be able to speed things up.


> 
> i ordered a 14mhz accelerator, is it as simple as just sitting that chip in
> or do i need to do some soldering?? ....
>

     If you ordered the 14MHz 65C816, what else you must do will depend
upon which accelerator board you plan to upgrade and your target speed.
Unless you decide to try using faster RAM or your osc module is soldered
to the board, there will probably be no need to do any soldering on the
board.

     There is general agreement that, up to around 12MHz-12.5MHz, you
have a good chance of upgrading a TWGS or Zip-GS by just swapping in the
new 65C816 and a higher speed oscillator module. The osc module needs to
be x4 the target speed (e.g. 48MHz for 12MHz) and needs to fit your
board's osc module socket. (If your osc module is soldered on, be sure
to order a socket for installing the new module.) 

     Beyond 12.5MHz, you may have to swap in faster RAM, increase board
voltage, etc.. Reports about what may or may not be required vary
because accelerator boards, versions of 65C816 employed, and GS setups
vary. For instance, the 20MHz 65C816's mentioned in a recent posting may
require no voltage increase to run at 15MHz or higher on some boards. On
the other hand, using a 20MHz chip, swapping in faster RAM, etc. may not
help at all if the real limit on speed is increased current load leading
to increased noise on the +5V and +12V power busses.   

     One popular approach is to order two or three osc modules (say
48MHz, 56MHz, and 60MHz) and experiment with operation at different
speeds. If, for example, you find that your board works fine at 14MHz
but starts to have problems at 15MHz, you can decide whether to stick
with 14MHz or experiment with mods to get reliable 15MHz operation. OR,
you may find that your board works fine at 15MHz with no further mods.



Rubywand