Can anyone help with chip dates? (Patreon)

I’ve been trying to pin down the age of the BGM machine I’m working on. To me the design feels 1988-1992, but that’s just a hunch.

This task is not made any easer with this being a commercial device as the dates for these are harder to pin down based on fashion. The internet is of no help and I can’t get to the motor to see if that has a date sticker.

My last hope for finding a date was the chips as sometimes these have date codes on them, however on this occasion I’m not seeing anything that clearly confirms a date. If you’re a chip expert could you have a glance over the pictures I’ve posted here and see if you can decypher anything from the text printed on them.

There are seven chips - some were easier to get a good angle on than others (the last one I've uploaded two pictures of) …but these are the clearest pictures I could capture.

UPDATE - We’re going with 1988 as the most recent date.