Sharp from 1988, I can't remember the model number but it's the cool one with dual CD players on the top. https://patents.google.com/patent/USD310220S/en
One of the big Yamaha's from 1989, it's hard to tell if it's portable. It looks like analog VU meters but it's hard to tell. https://patents.google.com/patent/USD322067S/en
I was looking around for more information on Sanyei Electronics Corporation, the manufacturer of Trident Boomboxes and they're still around, it looks like they do all kinds of consumer appliances. I found this ad for the Trident 9439F from 1976, it looks like a substantial boombox but very similar to all of the mono boxes being cranked out at this time. https://www.sanyeicorp.com/eng/
Add Lafayette to the list of first boomboxes with the RK-150 at an amazing 89.95 USD, huge money back then but this did have off the air recording and an FM band, although there wasn't a ton on it then. This was a big enough item to get front page placement! Found over on www.worldradiohistory.com if you want to see the whole catalog.