Um, no. Wang and Honeywell made mainframes as well as terminals. They also made the usual full line of disks, tapes, etc that were usually OEM products (like CDC disk drives, emulex tapes, etc).
The reason why Wang went under was the Dr. An Wang passed away and the next generation of corporate leadership had the technical IQ of a roach.
Honeywell just never really smart at how they marketed their products. They could never seem to get the major application developers to step up to putting out products on Honeywell mainframes and on Honeywell OS’s. When Oracle came along, you could see what was going to determine the future of a major mainframe/super-mini platform: Oracle. Oracle enabled some vendors to compete against IBM and DB2... and when a vendor didn’t have a port of Oracle on their platform... it was pretty much forward and down for them.
I participated (briefly) in the effort to port Oracle to Wang VS systems. It was like pounding a square peg into a round hole. But they got it done. Still, it was too late to save Wang from internal corporate malfeasance.
Honeywell made some nice gear. I didn’t get to play with it much, but I thought CP-6 was a hell of an OS. It got caught up in the four or five-way tug-of-war inside Honeywell for resources as they thought they were going to migrate everything over to Multics.
That's what I wrote if I'm not mistaken, lol.