Subject: Re: New chip in TWGS
From: supertimer@aol.com (Supertimer)
Newsgroups: comp.sys.apple2
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Date: 12 Sep 1999 17:41:03 GMT
References: <7rf34r$iee$1@holly.prod.itd.earthlink.net>
Organization: AOL http://www.aol.com
Message-ID: <19990912134103.01653.00000469@ng-fr1.aol.com>



"Trevor J. Mahan" <tjmahanNOSPAM@earthlink.net> wrote:

>Hello everyone:
>
>Well, I replaced the old TWGS 65C816 with the newer 65C816S8PL-14 and fired
>her up.  There is a noticeable speed difference, especially with loading
>System 6.0.  I need some help though with configuring it.  Rubywand or
>anyone with knowledge about these--How do I check what speed I'm truly
>running at?  Also, after setting control panel to fast and Transwarp speed,
>is there anything else to do with setting multipliers?  Is it like a PC MB,
>do I need to set any jumpers on the Card itself?  Any help would be very
>appreciated.  Thanks:)

There should be more than a noticeable speed difference.
The difference should be "WOW!"

You are correct that in addition to a CPU swap, you need
to do the equivalent of "changing multiplier settings" on a PC.
Take a look at the card and look at the upper corner of the
card.  There should be a shiny metal box.  This is the
oscillator.  Namely, a half-sized TTL oscillator.  This is the
CPU's clock and the oscillator runs at 4x the speed of the
CPU.

If you only change the CPU and left the oscillator at
28Mhz, you are in effect underclocking the fast CPU
at 7Mhz.

What you have to do is replace the current oscillator,
28Mhz (which means 7Mhz CPU speed) with a faster
one.  32Mhz oscillator means 8Mhz CPU.  36Mhz=4Mhz.

(Oops!  36Mhz oscillator = 9Mhz CPU speed.  Sorry
about the mistake.)

I suggest a 40Mhz and a 50Mhz one for testing 10Mhz
and 12.5Mhz CPU speeds and perhaps a few faster
ones to see how fast your TWGS can go.

As always, power down the TWGS before swapping
oscillators.

Half sized TTL oscillators can be found from various
electronics sources including http://www.digikey.com/
DigiKey.

No soldering necessary.  If you look closely, the oscillator
rests in a socket.  When you replace it, make sure to
keep the orientation correct.  Pin 1 on the oscillator is
marked on one corner with either a dot or a sharp corner.

One thing to note about these TTL oscillators is that there
are two kinds.  Full size TTL oscillators are rectangular.
Half size TTL oscillators are square.  TWGS uses half
size TTL oscillators.

The oscillators costs between 50 cents and a few dollars
each depending on the speed and where you get them.

http://www.digikey.com/ DigiKey is a good source and
with pretty fast service.  There may be other cheaper
sources too.

Actually, can someone post the sources, part numbers,
and prices for the oscillators?  A Radio Shack part
number and price would also be useful since some
TWGS upgraders might find a trip to the local Radio
Shack more convenient than mail order.

Good luck.