... or how to power retro hardware with modern PSU
... So, I've decided to take my work back underground ... to stop it falling into the wrong hands ...
A friend of mine, V-12/Tropyx, asked me to hack a PSU for his ZX Spectrum +2 - Black. That's the one with Amstrad mainboard.
After a short research, I already knew that in addition to +5 V and +12 V, black +2 requires -12 V line for normal operation. I was like hmmmmm ... hmmmmmmm ... and all of sudden I came up with an idea to use cased PSU from a small PC that I've disassembled a while back.
At least it sounded brilliant but was a bit harder to achieve ... KK not horribly hard after all ;)
PC PSUs has a lot of various voltage lines and -12 V is there as well, along with +12V/+5V.
The power socket in this speccy is a simple DIN-6 and I already had these plugs ordered for a different project (external SD2IEC). Soooo to work !
Sorting out an expansion port
First, I had to disassemble this unit to sort out an expansion port. Without it cleaned I wouldn't be able to test my setup since only hardware to load stuff on a speccy that I have is Divide2k14 by Lotharek.
Standard procedure was involved (I don't have all photos though) which is cleaning , applying solder and removing solder surplus with a soldering wick then reapplying a thinner layer of solder.
PSU after unscrewing top cover looks like this.
I've removed all unnecesary cabling and secured remaining cables inside.
I also needed a power on/off switch just for convienience.
PC PSUs are turned on by a motherboard. There is a special signal cable (usually green lead) for this task.
The solution is super simple. Green lead has to be grounded to keep PSU turned on and that can be done through a switch. Which is what I actually did right after cutting out a hole in a case for it.
NO SMOKE ! YAAAY :D