Some hints for kit-builder:


Nothing special here!

Before soldering the two 2x20 IDC connectors, you may pull off one makred pin on each.
Then you can later add a key-peg to the flat cable connectors, against mismatches.

The CPLDS can be programmed by you, see previous pages.

About LEDs in general

LED colors and brightness make a big difference in the "lock&feel".

Its not so easy to achive "retro light" with modern LEDs:
In the old days LEDs were very red and quite dim.
White lamps were made of light bulbs, often run under-powered, so they also had a warm white.

Todays LED in contrary outperform each other in "super-brightness".
I found even different batches of the same LED-type to get enhanced in brightness... apparently its common sense: "the brigther the better".

Especially the warm-white LEDs used here are this efficient, they need series resistors of 10K at 3.3V supply voltage, else they burn out your eyes.

Thats the reason I use sockets for all LEDs, to adapt to changes in LED brightness.


The LED-plug is straight-forward.

It consists of two parts. The upper label-panel should hold "click" onto the 1.8 mm LEDs without further fasteners.

qprobe2023 building ledplug overview

LED orientation is:

qprobe2023 building ledplug leds

While soldering, push the label-panel onto the LED repeatedly, to guard against major mismatches.

The two long-distance socket blocks is soldered last. Align it with another QBUS card to make sure "LED-plug" hovers over its neighbors.

qprobe2023 building ledplug socket

DriveBay Panel

The DriveBay-Panel is a complex sandwich construction.

qprobe2023 building drivebaypanel sandwich


The distance between base PCB and "label-panel" is dictated by the switches. The LEDs have to adapt.

Here soldering order is important.

  1. Solder the IDC connector and the resistor (sockets) to the back side first.

qprobe2023 building drivebaypanel 1

2. Mount the four distance bolts to the upper label-panel, with black screws.

3. Solder the LEDs.

They need to be soldered with "long legs", to the height of the upper label-panel. There is a 3D-printed alignment tool, which helps to solder upright and in right distance:

qprobe2023 building drivebaypanel ledhelper 1


qprobe2023 building drivebaypanel ledhelper 2

If you are right-hander, work the rows from left to right, and from "most away" toward you. Solder only one leg at first, and repeatly plug the upper label-panel onto your work for checkout.

To align the LEDs, mount the top panel over the LEDs after each row (or even after each half-row).
Solder the 2nd LED of each LED, then re-heat the 1st leg, to let tensions go.

4. Place the 7 switches. Make sure the one "momentary" switch is correctly orientated.

5. Finally mount the upper label-panel, then solder the switches .

6. IF the resistor packs are socketed, populate the sockets last.
Resistor packs are 2x4, but one is 2x5. You can populate a 2x4 there and plug a discrete 10K to the remaining socket holes.

Also solder the single 100K for 12V LED last from the backside.

7. Test: plug the panel to the QProbe,
add termination resistors on QProbe,
set the DIP switch on QProbe to "all OFF",
power the QProbe outside the QBUS card cage with 5V,
set the MODE switches to 0010,
and touch each QBUS signal pin with a GND probe.
The corresponding LED should shine, ADR and DATA are coupled pairs here.