Do you have a working circuit you want to understand or are you trying to repair one ? do you  have schematics ?

<nbucska@pcperipherals.com>

Yes, I have a working circuit with schematics.  I have determined some of the circuitry based on the limited information available, but I still have questions on some connections.   Ultimately, I want to be able to replace these components in the future with available parts, if/when there is a failure.  These digital devices are similiar to, but are not an exact drop in for Motorola or TI devices back in the early 70's.   The pin outs are different and there are different and/or addtional connections.  I also looked at old copies of Electronics World, Popular Electronics, and other electronic magazines from the 70's to find if  these devices were utilized in other designs. I only found a couple of designs using Teledyne Semiconductor devices with limited usefulness, mostly TI and Mot. devices were utilized back then.

These devices must be RTL or DTL logic, so very simple.
I think you could replace them with 14/16 pin modules
based on surface mount parts.

It may be worth ro redesign the whole thing, today it must be much easier.

<nbucska@pcperipherals.com>

YES, replacing them with SMD modules would work well.

However, there are a couple of connections that I am trying to understand what they are for, and that is why I am trying to locate the pinouts or data sheets. These devices are located on 3 separate PC Boards, so redesigning them, although fun, is not what I have time for right now.  I would rather plug in an equivalent DIP module based on a surface mount device, if needed, in the existing board(s) for now.   Thanks nbucska for your thoughts on this problem.