Consider: Webb Miller's 's' - It been on my 'todo' list to get it running on 6th edition, but I admit that is low on my priority list. But I have run it on a couple of other 8-bit systems

-- from the readme ---

# s
A tiny vi like screen editor

Original sources were published in this book:

Author: Webb Miller

Title: A software tools sampler

Publisher: Prentice-Hall, Inc. Upper Saddle River, NJ, USA ©1987

ISBN: 0-13-822305-X

Martin, a guy from one of my hangouts named <c.o.cpm>, located
the sources from this book. The repository starts from these
original sources. Martin also provided the initial CP/M patches
for compiling with HI-TECH C. Then the sources were overworked,
to get it compiled without warnings on old systems with K&R
C compiler, as well as modern systems with ANSI C compiler.

This version of s is known to compile on:

HI-TECH C for the Z80 under CP/M

clang under OSX

clang and gcc under Linux

Mark Williams K&R C compiler under COHERENT

On Mon, Mar 29, 2021 at 11:46 AM Andy Kosela <akosela@andykosela.com> wrote:

On Monday, March 29, 2021, Brantley Coile <brantley@coraid.com> wrote:
>
> From 1984, when I stopped using vi (vee eye), until the early 1990's, when
> I could use Sam, I used a slightly hacked version of ed. I added
> what the Labs called the "b" command. I had use some other character. Dennis
> Ritchie sent me a 8th Edition Unix manual, and I saw they had added almost
> the same thing and called the command by the second letter. Vi called
> it the last letter, "z."
>
> I've never found ed slows me down. Some things I would have used awk/sed
> for that I now use Sam's command window for, but that's a bad thing. I still
> use ed a lot along side Sam.
>

If ed(1) had cursor positioning and full screen capabilities along
with line oriented editing (similar to Atari 8-bit default editor) it
would be perfect. I still love it though and use it pretty often.

--Andy