Search found 1312 matches

by Pr0f
Fri Mar 01, 2024 4:27 pm
Forum: Hardware
Topic: Thor 8 with no keyboard
Replies: 7
Views: 1206

Re: Thor 8 with no keyboard

I watched those as well, wonder who got them?
by Pr0f
Mon Feb 26, 2024 9:50 am
Forum: Hardware
Topic: Switching Regulator?
Replies: 37
Views: 3894

Re: Switching Regulator?

tofro wrote: Mon Feb 26, 2024 8:44 am Well, I think the answer to the OP's question is as simple as pragmatic: If it works, use it, if it doesn't, don't :)
Love that :-)
by Pr0f
Mon Feb 26, 2024 8:19 am
Forum: Hardware
Topic: Switching Regulator?
Replies: 37
Views: 3894

Re: Switching Regulator?

The only issue I could see is that some of the older switching regulator circuits operate in the lower frequencies and might produce radiated interference that could affect the microdrives, but more modern designs use very high KHz or even MHz range and so this is less likely going to be an issue. A...
by Pr0f
Thu Feb 22, 2024 11:56 am
Forum: Hardware
Topic: Floppy enclosure 3d print
Replies: 7
Views: 977

Re: Floppy enclosure 3d print

That's nice :-)
by Pr0f
Sat Feb 17, 2024 11:13 am
Forum: General QL Chat
Topic: My rare old QL version AH
Replies: 22
Views: 2428

Re: My rare old QL version AH

No photo's I'm afraid - but if you look at the issue 5 board - there is a wire link or zero ohm resistor that connects pin 40 to VCC - it's marked on the PCB as a diode - and that's the first clue - this is the VCC for battery - which should be a wired or'd pair of diodes - one that from VCC to pin ...
by Pr0f
Fri Feb 16, 2024 7:32 am
Forum: General QL Chat
Topic: My rare old QL version AH
Replies: 22
Views: 2428

Re: My rare old QL version AH

The battery area was under the heatsink and near the modulator - but I've never seen a board fitted with it. I did make this mod myself on and old QL, but it involves some tweaking with the reset signal during power up - if I did it again I'd use one of the power management chips that locks out the ...
by Pr0f
Thu Feb 15, 2024 3:22 pm
Forum: Hardware
Topic: QL PSU Voltages
Replies: 20
Views: 793

Re: QL PSU Voltages

That should be more than enough I would have thought
by Pr0f
Thu Feb 15, 2024 1:58 pm
Forum: Hardware
Topic: QL PSU Voltages
Replies: 20
Views: 793

Re: QL PSU Voltages

One thing I would say - Charlies vRetro uses some sort of stepped square wave format for the AC voltage - it works fine with the power circuity in the QL for generating +/- 12V using the small L series TO92 regulators (look like transistors), and I don't think this AC voltage is used any where else ...
by Pr0f
Thu Feb 15, 2024 1:54 pm
Forum: Hardware
Topic: QL PSU Voltages
Replies: 20
Views: 793

Re: QL PSU Voltages

I know that if I have too much plugged in (curse those backplanes :-) ) the vRetro will gracefully abort trying to power the QL up. but it will happily run one expansion card in the QL no problem. I can't remember what spec my little power supply is, but I think it's 12V at 2.5A - which provides mor...
by Pr0f
Thu Feb 15, 2024 1:20 pm
Forum: Hardware
Topic: QL PSU Voltages
Replies: 20
Views: 793

Re: QL PSU Voltages

What's the symptoms with the vRetro psu?