CPC6128 and ATX PSU switch question

[kikendo]

Hello everyone and welcome myself to the CPCwiki 


I just proceeded to adapt an ATX power supply to an Amstrad 6128 that I just acquired, following the pinouts on this page: Powering a CPC 6128 from a Sinclar Spectrum +3 PSU - CPCWiki


I basically just adapted a big molex plug to the connectors of the CPC so I could easily connect the power supply.

Now the question is the switch. The Amstrad has a switch and I was wondering if the following procedure is right:


- Disconnect switch from motherboard
- Connect switch to PWRON and GND signals on ATX header
- Done


I don't really understand how the switch works on the computer but I am guessing leaving it connected to the motherboard will just be a problem and a potential hazard.

All I want is to have just ONE switch to operate the computer.


Any suggestions? Am I thinking things wrong?

[opticpow]

Hi Kikendo,

I would suggest that you leave the switch in the CPC alone, and get a new switch for the powersupply. Leaving the switch in the CPC will not hurt anything, and IMHO I'm more for leaving the CPC original.

If you do decide to remove the CPC switch, then you will need to join the wires (making sure to insulate the connection) that connect to the switch to effectively have the CPC on all the time.

Cheers,

Optic

[kikendo]

Hey there,

Maybe I didn't make myself clear: I am not removing the switch from the CPC: I am disconnecting it from the motherboard and connecting it to the PSU.

The question is: will this work? Does the motherboard connector need to be bridged then? How is this switch connected? How does it power up the machine? If I didn't get your second paragraph wrong, yes, I need to bridge the connector to get the motherboard to work when power is switched on from the power supply instead. Have you even seen the connector I am referring to? I ask because you have only one post in these forums.

I am assuming an Amstrad monitor gives constant current through the power headers, so the block is in the motherboard. If suddenly the switching on function was to be moved to the power supply, I would assume that this motherboard connector should be bridged for the machine to function, otherwise I would need two switches. The idea here is to use just one switch, the one the CPC already came with.

Cheers

[IanS]

The power switch on the 6128 only switches the 5V supply.
If you disconnect the switch from the motherboad, you will need to short the pins on the connector that you removed the switch from.

I would just leave the switch on the 6128 permanently switched on and use a separate switch on the psu to switch the cpc on and off.

[kikendo]

That exactly responds to what I want to know, thanks Ian.

So I'll disconnect the switch from the motherboard, bridge that connector and attach this to the PSU.

So the +12V is always on, even when you switch the computer off? That's kinda odd.

[IanS]

So the +12V is always on, even when you switch the computer off? That's kinda odd.

The +12V was only on when the monitor was on and only connects to the floppy drive. The switch effectively becomes a way to rest the cpc when the monitor is on.

[kikendo]

Interesting that the floppy drive won't be allowed to "rest" though when the monitor is no
Thanks for all the info!I can proceed with my mod now

I now gotta find a suitable 3.5" floppy drive!

[Bryce]

I'd just bridge the PWRON to GND on the PSU and use the switch on the CPC as normal. Surely you're not going to leave the PSU plugged in all the time when you are using the CPC??

Bryce.

[kikendo]

When I'm done doing what I'm doing, you'll understand. I know what I am doing

[Bryce]

I don't doubt that. I was just saying how I'd do it

Bryce.

[kikendo]

I appreciate any and all inputs.
Although not new at all to this retrocomputer stuff, I am quite new to the Amstrad.
I actually had one many years ago which I never used because I never went and did all these modifications. Now I'm serious