It all makes sense to me v(._. )v

https://vintageapple.org/inside_o/pdf/Inside_Macintosh_Volum...

“Calls to the Toolbox and Operating System via the trap dispatch table are implemented by means of the MC68000's "1010 emulator" trap. To issue such a call in assembly language, you use one of the trap macros defined in the macro files. When you assemble your program, the macro generates a trap word in the machine-language code. A trap word always begins with the hexadecimal digit $A (binary 1010); the rest of the word identifies the routine you're calling, along with some additional information pertaining to the call.”

It is written very strangely. It's not exactly like they reached the decision to use F-line traps for co-processors, I'm pretty sure F-line traps were designated by Motorola for co-processors, and A-line traps were free for use for OS and Toolbox trap instructions.

The "software crashed expecting a co-processor" part doesn't make any sense either, you were always supposed to check if a co-processor was available. There was no big rug pull or anything, both the first models and some later models simply did not have co-processors. Developers were provided this information.

And the last two sentences seem completely unrelated to the prior ones, so I'm not really sure what they're trying to string together.

It mostly makes sense to me. "Advanced CPUs" should have been "advanced models" (The Mac LC) missing coprocessors.

And it probably was true that crashes in Microsoft products got patched in the system, while most other app developers did not get that courtesy.