Wat is the oldest chip in your parts bin?

In my case it is the same. My most probably oldest chip is UCY7406 containing 6 invertors.

This chip we used at high school for basic logic labs, but in personal project I never used it. The oldest chip which I bought and used for leaning in my beginings is ATmega16.

I have several old chips in my collection, which makes a lot of sense as I started my electronics hobby/career in the early 70's.  I have several high-power vacuum tubes (from commercial FM transmitters, some up to 5000 Watts).  In IC's I have several gold cased ICs, including simple logic gates and such from, my early years in the military electronics field and many early processors and other long ago obsolete components.  I have a bunch of old germanium and silicon chips from some early work I did in electronic music and synthesizers.  I will have to see if I can dig up a specimen to share pictures. 

I wish I had an LM109/LM309 more closely related to https://en.wikipedia.org/wiki/Bob_Widlar 

Random TLL inverter

Here's one of a similar vintage. The carbon-loaded anti-static foam is now crumbling.

Was that the UART peripheral in their set of chips?

This next one is a very curious beast. I think the 1771 was a disc controller, but why was there a painted-over window on the top? Even stranger, there's one underneath, too. Perhaps they were programming their own chips.

That is an amazing amount of effort especially writing your own dissambler.  The programmers of yesterday did seem to like jumping in and out of subroutines.  I formed that opinion, anyway, after seeing the dissasmbly of some Intellivision games.  And truth be told I couldn't extract enough meaning from the generated code to make any sense of it.  Best of luck if you ever resume this project again.

I have a lot of IC's from the early 1970's.

Many have gold coatings, so I hold on to them because they are probably quite valuable by now.

I will search my stash, we might get lucky.

Actually, I found that was one of the easier parts as Hitachi had a datasheet on the HD6303 so I had the opcode map and the number of operands each opcode expected. I knew where the processor looked for the interrupt vector table in memory so the value stored there at told me the address where the executable code started. From there it is just a case of looking up the opcode and then finding how many operands it expects and away you go. It was a bit tedious as the data sheet was scanned so no quick cut and paste into the program. Add in a few extra routines to calculate addressing offsets to make it more readable. In-line data can be an issue. Also keeping an eye on the interrupt vector table can identify start addresses of other code blocks.  

If you want effort, then that was months of looking at data captures from a scope trying to figure out patterns in the data. It turned out that the comms was asymmetrically encoded so the few ASCII characters in the config section were initially obfuscated. Then finally once I had identified the encoding method there was a 'Twin Peaks moment' 

https://www.youtube.com/watch?v=mbi7rq-TSk8&t=78s

as the hex sequence for the Program ID and data ID strings finally matched one of the data captures and confirmed I was really on the right track.

If the code was originally generated from an optimising compiler, then it often can often be hard to follow as the optimisation can save program cycles by doing certain procedures in rather non-intuitive ways. Also by having lots of near jumps you can reduce the overall code size to fit in the limited memory by reusing code blocks, however once again it makes it a lot harder to follow.

It would make life easier I think if I had a way of turning the listing into a graphical diagram with the blocks of code linked by the jumps such that you could slide things around so that the related sections were next to each other. Also a way of labelling and commenting what you had identified so far. I think that's what the call 'data graph' structures in programming lingo ?  I once saw this done manually with string and post-it notes !

If I was a bit further along the line, then I might have given the LabVIEW challenge a go using it to connect to the ECU (or rather the ECU protocol simulator that I have also written as part of this project). However  I'm not sure what is involved in getting LabVIEW to talk to the ECU protocol and parse the data.

Yes - the ACIA. I also have a bunch of chips in crumbling black anti static foam like what your chip is on.

I used to design with a lot of Signetics parts in the 70's.  I've got one of the early 555 parts.  Shown here with a 566 VCO and 5556 opamp.

I probably have some of the 56x series PLLs around somewhere.  The 566 is the VCO from one of those parts.

The earliest part that was easy to find was a 7400 series part from TI.

And, of course I used a lot of opamps.  Here are a couple of National Semi parts (never used spares) - an uncompensated 709 and a dual 747.

I'm sure I have lots of other old stuff somewhere.  Back in those days I used a lot of MECL from Motorola and analog parts from Fairchild and TI.