DCTL originally meant "Direct Coupled Transistor Logic", as described by @Tim on his great pages about the CDC6600 technology.
I have tried to increase the speed/power ratio with the help of a finely tuned base capacitor (C) and a Baker clamp diode (D) which seems to provide a propagation time of 2ns per inverter and/or a much better low-power performance. So this gives a new meaning to DCTL : Diode Capacitor Transistor Logic.
It's pretty easy to use yet quite unusual because each gate is only an inverter that provides an open-collector output, so it's all "OR-tied" logic, there is no dedicated inputs for each signal.
I have presented/introduced the individual gate in the description page of the project:
![](https://cdn.hackaday.io/images/7506491637154444017.png)
I have worked a bit more to make the PCB more compact:
![](https://cdn.hackaday.io/images/358441637154497447.png)
There is only one via now, and all the passives are on the bottom layer, which could be pick&placed by machines. Here I only use 0603 parts but they could be changed to 0402 or anything you want.
Here are the top and bottom layouts:
![](https://cdn.hackaday.io/images/1150451637154586712.png)
Now, the Ground/0V rail is on the top layer and directly connected to the PMBT2369's emitter.
There is some room at the right of the clamp diode.
![](https://cdn.hackaday.io/images/1340961637154687062.png)
The bottom layer has the passives (2 cap, 2 res) and the Vcc supply rail.
I added windows on the rails to make them easier to solder to sources/supplies.
Overall I have tried to reduce the "height" of the gate, compared to the first version. This makes the strips more densely packed and more cost-effective.
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