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11.4.3 Afterburner Switch
The Afterburner040 / 030 Switch
The Afterburner is more compatible than most people might think,
but it's still not 100%. Albeit we hardly need to use 040-incompatible
programs, we all have a favourite game or demo that we're missing. It
might even be an ST-program, like Super Sprint, that work with the 030
and not the 040... That's why it would be nice to have a possibility
to switch back to the 030-processor,especially since the 030 still is
there! Switches have been available for some time now, but when you
have to physically remove the AB-card, it's not very handy. After some
exploration, I finally came up with a way to avoid this, and that's
what this web-page is all about!
I would like to thank my good friend Jo Even
Yours truly
Disclaimer
I do not take any responsability for what you do with your
computer. If you choose to follow these instructions, you do it at
your own risk. I don't earn any money on this, and I don't intend to.
All I can say is that it worked fine with mine and it might not do
with yours! There might also be errors in this text!
Ingredients
* A two pole relay.
The resistors must be rated higher than the resistance in the
respective systems!
At this point, I guess it's no need to explain how to unscrew your
own computer, and besides there are so many different casings that it
would just be impossible to cover all possibilities.
Hopefully you've got yourself a relay that fits between the motherboard and the Afterburner-card, as some relays are a bit too big... I believe that the best place to put the relay is directly to the
left to the U62-chip. This is where you'll get the shortest cables
without too much fuzz.
Use some glue or tape to fix the relay in place. It's up to you to
find out if it best to do it before or after you have soldered all the
wires.
Relay Pinout
Figure 1 - Relay seen from below
Note that the pin configuration differs from relay to relay. You have to figure out for yourself how the pin configuration is on your relay, but the one shown here is a good example... Note! Scandinavian users might consider getting the ELFA-catalog.
It contains very detailed information about relays, and they also have
a good range of different relays. I recomend it!
Red Wire
After soldering the red wire to the correct pin on the relay, you
must solder the opposite end to one of the following places:
Right pin of inductor L177 (Bottom left of the motherboard)
Pin 20 on U62, U63, U67 or U68
Or any other +5V source
Black Wire
Solder one of the black wires to the relay as shown in fig. 1, and
solder the other end of the wire to the switch. Then take one of the
other black wires and solder it to the other pole of the switch. The
other end of the second wire must be soldered to ground. It's easiest
to use the outer grounding rail, but it should be easy to find other
places as the PCB is full of grounding points.
Purple Wire
This is the same purple wire as the one on the AB-cable. Remove it
from pin 4 on the U68 and solder it to the relay as shown on the
figure 1.
Important pins on the 030
Figure 2 - Lower left corner of the 030.
Orange Wire
Solder the orange wire to the relay (fig. 1) and to one of the
following places:
Pad 16 at the 030 (as shown in fig. 2) Pin 4 on U68 (Recommended)
Light Green Wire
Solder the green wire to the relay (fig. 1) and solder the other
end to pin 16 on the 030. (Fig. 2) Be careful! It's far from
impossible to repair a broken chip-leg, but it's very annoying! I know
because I've broken two allready;)
Dark Green Wire
Take one of the 10kOhm resistors and solder it to the outer
grounding rail. Solder one of the remaining black wires to the other
end of the resistor. Then you must solder both the black wire and the
dark green wire to the relay (fig. 1). Take the remaining end of the
dark green wire and solder it to pin 17 on the 030 (fig. 2).
Light Blue Wire
Solder the light blue wire to the relay and to one of the
following places:
Dark Blue Wire
Take the remaining black wire and solder it to the last resistor.
Solder the other end of the resistor to a nearby grounding point
(outer rail or wherever) Solder both the dark blue wire and the black
wire to the relay (fig. 1). The remaining end of the dark blue wire
should then be soldered to to pin 11 on the mach chip. Note that it
might be smart to use some kind of a plug and socket for this. It'll
make it easier if you have to remove the Afterburner later on...
Operation
It's advisable to switch off your computer before switching, but
if you do it without turning off, you might press reset a couple of
times.
That's all...
If you encounter problems or have questions, just E-mail me at the
following address:
Problems
If you have problems, try reseting the computer a couple of times.
You should try both modes too. Don't worry if things don't work the
first time! You can still go back to how it was before...
Check that:
* you have the jumper on pins 20 & 22 on J20...
* the track is properly cutted
* you have the correct relay pinout.
* the relay really works.
* none of the wires are misplaced or switched.
* you using a switch with only two poles. If not, check that the
relay gets grounded in one of the switch positions. If not, move one
of the black wires to another pole on the switch and do another test.
* your relay work in the same manner as mine. With a different
relay you might need to ground the black wire, and use a three pole
switch connected to the red wire so that the red wire is either
connected to +5V (Mode 1) or ground(Mode 2)... This is due to the
nature of the electro-mechanical relays I used.
* the resistors is rated high enough.
Typical problems are:
* Black screen
Problem that migth arise:
Copyright © Robert Schaffner (support@doitarchive.de) Letzte Aktualisierung am 23. Dezember 2003 |
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