I find that I am most productive when working with a given logic family when I have a visual, concise reference. Thus I've digitally drawn the entire TI CD4000 logic portfolio on a set of 4x6 reference cards. Included are also a few obsolete but still useful chips available on the secondary market, like the 4008 adder for example.
The CD4000 logic family is alive and well, and most of it is still made by TI with the exception of the 4008 adder. All of the 14- and 16-pin functions are still sold in DIP. The 24-pin functions are offered in surface-mount packages only.
This logic family is well suited for unregulated supplies over a wide 5:1 range - from 3V to 15V. It is also fairly slow and has low EMI. It interoperates very well with low-noise analog circuitry.
The standard drive outputs can drive LEDs directly from 3V up to 5V supplies - no resistors needed. The standard drive outputs in practice survive shorts to supply rails up to 5V, and possibly even higher, although local die heating becomes problematic then.
I've done the drawings in Goodnotes, and have included both the source file as well as a PDF render in the files section.
This project is licensed under the Attribution Non-Commercial International 4.0 (CC-BY-NC 4.0) license.
It is my hope that the homebrew CPU community will find this reference useful, as well as anyone building "retro" circuits. Far from obsolete, the CD4000 logic family finds many uses today due to its versatility and docility.