The "ok" prompt is from "OpenBoot", a boot manager, written in FORTH:
https://docs.oracle.com/cd/E19253-01/816-1177-10/816-1177-10.pdf
Jim
From: "Dan Cross" <crossd@gmail.com>
To: "Warner Losh" <imp@bsdimp.com>
Cc: "Grant Taylor" <gtaylor@tnetconsulting.net>, "The Unix Heritage Society" <tuhs@tuhs.org>
Sent: Tuesday, January 2, 2024 2:50:52 PM
Subject: [TUHS] Re: Question about BSD disklabel history
On Tue, Jan 2, 2024 at 2:00 PM Warner Losh <imp@bsdimp.com> wrote:
> [snip]
> Yea, I have a memory of the Sun 3 (68k) machines having a different ROM than the Sun 4 (sparc) machines in the late 80s/early 90s with similar interfaces, but the Sun 3's being simpler. Maybe I just worked with older Sun 3's that didn't have a newer OpenFirmware.
Sun 3/50 and Sun 3/60 definitely had a different PROM arrangement than
SPARCstations. However, I have a vague memory that the Sun 3/80 used
OpenFirmware. The 3/80 (and similar Sun-3x machines introduced at the
same time) would have been among the last, if not the last,
MC68k-based Sun3 machine. I may be wrong, though; it's been a while.
Regardless, I vaguely remember the "ok" prompt on a 3/80.
- Dan C.