It sounds like you have a unit that is variously described using terms like "benchtop trainer", "universal breadboard", "tabletop electronics lab", et al. They were - and continue to be - staples of the electronics education industry. Over the years there must have been hundreds of companies that produced them in various formats. Some of the correspondence schools, as well as a few traditional colleges and high schools, had somebody's standard model "customized" in some way (maybe just a silk-screened logo on the panel), and a few even crafted their own versions in-house. In my opinion it's worthwhile to have one of these things on the bench.
If you can identify the original manufacturer, you may be able to locate a schematic and parts list. (For example, you can get the schematic for one variant, the "PAD-234A", at http://www.elexp.com/tst_234.htm ) While the basic architecture of these units was quite similar from one manufacturer to another, the implementation details varied quite a bit. In a school environment they took quite a bit of abuse - and, frankly, many of them didn't have adequate protection circuitry or suitably over-rated components to hold their own against students' mistakes. If all 3 power supplies as well as the function generator of your unit are working, you are fortunate!
I've looked at either hardware or schematics for at least half a dozen of these trainers, and all the "Function Generator" sections used the '8038, or some variant or descendant of that chip such as the '2206. It's mentioned in "25 Microchips That Shook The World" - but I know that it was available at least a decade earlier than the listed "1983" introduction date. At one time I think there were 3 or 4 different manufacturers of functionally similar chips but all of them have been discontinued. (Exar may still offer the VCO section of the '8038 as a stand-alone chip, but it doesn't have the waveshaping circuitry.) You may find the chips at some of the places that carry surplus/salvage components such as All Electronics, Jameco, Marlin Jones, etc.
Dale
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Old breadboard from a college program???
