alx asked:
A500 PSUs have a higher output than the original A1200 ones, and are prefered for... an expanded A1200!
Are you sure of this? I've got an A500 - could I use the PSU to give the 1200 extra juice?
Short answer- YES! On the base of many A1200 PSUs can be seen the words: "A600" or "A300". The
A300 was the ORIGINAL A600 designation.
Meaning: An A1200 is sold with a PSU no more powerful than an A600's!
Long answer- A modified XT(or AT) PSU is an even BETTER proposition!
DiagramUse
J1 &
J2 to obtain the +5V, +12V, -12V, GND & GND.
"On the bottom of the Amiga 500 power supply, as well as in the user's
manual, the following diagram of the Amiga 500's connector appears:
+--\___/--+
| 3 4 |
| 5 |
| 2 1 |
+---------+
where:
pin 1: +5VDC
pin 2: Shield Ground
pin 3: +12VDC
pin 4: Signal Ground
pin 5: -12VDC
With the power supply disconnected from the Amiga, turn the power supply on
and verify these voltages, BEING CAREFUL NOT TO SHORT OUT ANY PINS! All
voltage readings should be performed with the voltmeter's ground cable
connected to the connector's Signal Ground. Record each pin's Voltage.
Once satisfied with the Pin versus Voltage supplied, turn off the power
supply and unplug it from the wall.
Cut The Amiga 500 side of the power cord leaving approximately 10 inches
sticking out of the original power supply. Carefully strip back 1 inch of
cable insulation from each side and then strip each wire, leaving about
1/4 inch of the wire showing.
Crimp then solder onto each wire on the power supply side, a female
connector. Do the same on the side normally attached to the Amiga 500
except use MALE connectors. Each side should have a total of 5 wires with
connectors.
Now insert the female connectors into the Molex-style female connector.
Do the same for the male connectors, BUT MAKE SURE THAT THE WIRE COLORS ON
EACH SIDE OF THE CONNECTOR ARE THE SAME WHEN THE MOLEX-type CONNECTORS
ARE PLUGGED INTO EACH OTHER.
Once completed, verify that there are no shorts between the various wires.
Plug the two MOLEX-style connectors together, plug in the Amiga 500's power
supply and re-verify the voltages. They should be the same as previously
measured.
Once satisfied, your Amiga 500 will operate with the original power supply.
(This allows the A500 PSU to be put back into use as a backup)
Now on to the PC-XT power supply. Referring to the picture, PC-XTpwr.pic,
1) Cut the 3, +5VDC power wires on connector J1 and then wire all
three to a single female connector. Label this +5V.
2) Cut the +12VDC power wire on connector J2 and then crimp and
solder it to a female connector. Label this +12V.
3) Cut the -12VDC power wire on connector J2 and then crimp and
solder it to a female connector. Label this -12V.
4) Cut the 4, GND power wires two on J1 and two on J2 and then
wire all four to a single female connector.
5) Connect on end of the multistranded hookup wire to a female
connector and crimp the ring connector on the other end.
Using the Ohmmeter and the previous diagram, determine which pin in the
Amiga 500 power cable MOLEX-type connector carries the +5 volts. Connect
the PC-XT wire labelled +5V to the same slot in the remaining plastic
connector. Repeat this procedure for +12V, -12V and Ground.
The multistranded hoodup wire should be inserted into the slot where
connection will be made with the pin labelled SHIELD GROUND. Remove
one of the screws in the PC-XT power supply, attach the ring connector, and
the put the screw back.
****************************************************************
** WARNING!!!!! **
** **
** IT IS IMPERATIVE THAT THE SHIELD CONNECTOR BE SCREWED **
** SECURLY TO THE PC-XT POWER SUPPLY. FAILURE TO DO SO MAY **
** DAMAGE THE AMIGA 500. **
****************************************************************
Plug the Amiga 500 power cable into the PC-XT power supply, BUT DON'T
ATTACH IT TO THE 500 YET. ALL POWER CONNECTIONS MUST BE VERIFIED!
Plug the PC-XT power supply into a wall outlet, power it on and using the
voltage meter verify that all of the power connections are the same as
previously checked.
Once satisfied, turn off the power supply, unplug the power supply from the
wall, install the power supply in a suitable case and connect to the
Amiga 500. If you wish, you may plug the monitor into the switched AC
connector on the power supply.
IF YOU WERE CAREFUL AND VERIFIED ALL CONNECTIONS, TURNING ON THE PC-XT
power supply should result in the complete powering of your system.
IF YOU FAILED TO CHECK THE VOLTAGES, IT IS LIKELY THAT YOU MADE A MISTAKE
AND TURNING ON THE POWER SUPPLY AT THIS TIME WILL RESULT IN THE COMPLETE
LOSS OF YOUR SYSTEM.
(
AT PSUs colour-coding is different .... varify pins with an Ohmmeter)"
