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Note there were two versions of Logo for the Apple II. The other was developed by Logo Computer Systems Inc. (I was one of the staff). Our version was writte
by jrd259 8y ago
Note there were two versions of Logo for the Apple II. The other was developed by Logo Computer Systems Inc. (I was one of the staff). Our version was written first in Lisp (on Lisp Machines) then manually compiled to assembler. The Lisp development environment included a full 6502 emulator, allowing the developers to execute Logo either at the Lisp level (fast) or to drop down into the instruction level (slow). The emulator also emulated the Apple II's graphics.
- effish 8y agoSerious overkill huh? I do have the sources for both those, but only printed not electronic media.
- larsbrinkhoff 8y agoWould it be possible to scan those in?
- jackpirate 8y agoWhat does "manually compiled to assembler" even mean? How is that different from "rewriting it in assembler"?
- effish 8y agoThere is a gray area there. But we are talking about translating an existing model program and algorithms, not looking at the program as a black box and recreating its behavior. As the person who translated the Pascal Logo model to TI9900 assembler it was definitely the case that at the beginning of the project I translated every line of Pascal to a few instructions of assembler. By the end I was just looking at the gist of what a routine would do (its “contract” as they say) and writing it in assembler as you would new code. It’s much like translating a literary work. There’s a famous quotation (which I’m not comfortable relating in full) about translations being either faithful or beautiful but not both. Essentially maybe I became a fluent native speaker of 9900 assembler.