Donald Knuth used a pre-release version of Photoshop (at Adobe headquarters after the employees had gone home for the day) to process the images for his book 3:16. He was using multiple Macs to parallelize his process, and there were frequent crashes. This was back in the days of Macs with 512K of RAM which makes your 128MB Mac seem positively capacious by comparison.
He stated that would have been in the summer of 1989-- so Macs actually could have had anywhere from 1-128MB.
128MB would be unlikely, but the SE/30 was released in January of the same year.