Opus 5.5 can write IBM 1401 Autocoder very well (used on the Computer History Museum's pair of working 1401s). THAT is astounding to me.

Related, for the CHM's IBM 1620 project, we received 4 entire cabinets filled with punched cards from Indiana University -- a prof there took every useful IBM 1620 program, and immediately made a copy and put those cards into what ended up being 4 card cabinets -- those deep things, with decks on both sides of each drawer. About 10' x 5' tall x 6' deep. As part of the project, we had a card reader that was capable of reading 'column binary' -- that is, it could read the bits on the cards, not just the encodings. I wrote a program to read ALL of those card decks in column binary and then took those around 200 files and put them into a single .ZIP file.

That .ZIP file holding ALL of the known commercial / scientific computing SW for the IBM 1620 fit onto exactly .... ONE standard 1.44 MB Floppy Diskette.