An interpreter and editor in 1K sounds very challenging! Do you mean 1K of Squeak bytecode? Including vectors of literals and selectors?
The 1KB target was for Baby 8 (the associated processor) binary code. That processor had a few quirks (like only indirect addressing outside the "zero page") and the language design partly reflected that. Seeing other people fit Lisp into less than 512 bytes made me think I had sacrificed too much functionality for size.
The incomplete Squeak code was just a quick test to see if the language made sense at all before wasting time doing the assembly version.
The sieve example uses a single 8Kword array https://github.com/jeceljr/baby8/blob/main/examples/bla/siev...