For a long time it has bugged me that there is no easy way to add ANSI codes to a text file or the output of a command. I would have to add them in a tedious way with sed or awk and try to remember the obscure escape codes for the ANSI sequences. Well, I've written a surprisingly simple bash script that lets me pipe any text or output of any command through it and do things like:
anstyle line 4 bold
or
anstyle str elephant red g

The first one makes the fourth line of whatever is piped into it bold text. (Surprise, surprise.) The second one prints in red every occurrence of "elephant" in the piped text.

But you can do more complex things too, like reversing the foreground and background colors of all lines between and including two line numbers. You can change to italic all lines between and including two lines that contain a start string and a stop string. You can highlight the last line of the input file (regardless of how long the file is) by making its background some color, say, yellow. And much more.

And I can include several of those definitions in the single anstyle command. I'm very happy that this makes a lot of minor, but annoying things into trivial tasks.

#! /bin/bash

# anstyle
# ANSI styling of text via simple commands

# Miriam
# Saturday 2026-10-10 09:49:30 pm
#
# This grew out of my frustration that I couldn't do easy ANSI styling
# of a command's output without resorting to fairly obscure uses
# of awk or sed for what may be a quick, off-hand, one-time use.
#
# line
#	awk 'NR==1 {print "\033[1m" $0 "\033[0m";next}1'
#	awk 'NR==1 {print "\033[1m" $0 "\033[0m"} NR>1'
# range
#	awk 'NR==4, NR==6{print "\033[1m" $0 "\033[0m";next}1'
#	awk '/dev/,/tmp/{print "\033[1m" $0 "\033[0m";next}1'
#	awk 'NR==4, 0{print "\033[1m" $0 "\033[0m";next}1'
#	awk 'NR>=4{print "\033[1m" $0 "\033[0m";next}1'
# string highlight
#	awk '{gsub(/dev/, "\033[31mdev\033[0m"); print}'
#	In order to select the nth match awk needs a loop and counter
#
# line
#	sed '1s/^/\c[[1m/; 1s/$/\c[[0m/'
#	sed '1s/.*/\c[[1m&\c[[0m/'
# line range
#	sed '2,$s/.*/\c[[1m&\c[[0m/'
#	sed '/nvme/,/user/s/.*/\c[[31m&\c[[0m/'
# string highlight
#	sed 's/dev/\c[[31m&\c[[0m/g'		# all occurrences of "dev"
#	sed 's/dev/\c[[31m&\c[[0m/2'		# 2nd occurrence on every line
#	sed -z 's/dev/\c[[31m&\c[[0m/4'	# 4th occurrence in the file
# multiple commands
#	sed '1s/.*/\c[[1m&\c[[0m/;/nvme/,/user/s/.*/\c[[31m&\c[[0m/'
#
# NOTE: ASCII escape char is \d27 or \o033 or \x1b or \c[ 
#
# Commands
#	line   affects the nth line
#	line   affects lines containing pattern
#	line   affects given lines
#	str  
# Perhaps use commands like this:
#	anstyle line 1,3 bold line 5 redfg str text italic 2 file.txt
# makes file.txt lines 1 to 3 bold, line 5 red fg, 2nd pattern "text" italic 

declare -A ansi

ansi[reset]='\c[[0m'

ansi[bold]='\c[[1m'
ansi[unbold]='\c[[21m'
ansi[dim]='\c[[2m'
ansi[undim]='\c[[22m'
ansi[italic]='\c[[3m'
ansi[unitalic]='\c[[23m'
ansi[uline]='\c[[4m'
ansi[unuline]='\c[[24m'
ansi[blink]='\c[[5m'
ansi[unblink]='\c[[25m'
ansi[fblink]='\c[[6m'
ansi[unfblink]='\c[[26m'
ansi[reverse]='\c[[7m'
ansi[unreverse]='\c[[27m'
ansi[hide]='\c[[8m'
ansi[unhide]='\c[[28m'
ansi[strike]='\c[[9m'
ansi[unstrike]='\c[[29m'

# ===colors ===
# --- fg ---
ansi[black]='\c[[30m'
ansi[red]='\c[[31m'
ansi[green]='\c[[32m'
ansi[orange]='\c[[33m'
ansi[blue]='\c[[34m'
ansi[violet]='\c[[35m'
ansi[cyan]='\c[[36m'
ansi[lgray]='\c[[37m'

# --- bg ---
ansi[blackbg]='\c[[40m'
ansi[redbg]='\c[[41m'
ansi[greenbg]='\c[[42m'
ansi[orangebg]='\c[[43m'
ansi[bluebg]='\c[[44m'
ansi[violetbg]='\c[[45m'
ansi[cyanbg]='\c[[46m'
ansi[lgraybg]='\c[[47m'

# --- light colors ---
# --- fg ---
ansi[dgray]='\c[[30m'
ansi[lred]='\c[[31m'
ansi[lgreen]='\c[[32m'
ansi[yellow]='\c[[33m'
ansi[lblue]='\c[[34m'
ansi[lviolet]='\c[[35m'
ansi[lcyan]='\c[[36m'
ansi[white]='\c[[37m'

# --- bg ---
ansi[dgraybg]='\c[[40m'
ansi[lredbg]='\c[[41m'
ansi[lgreenbg]='\c[[42m'
ansi[yellowbg]='\c[[43m'
ansi[lbluebg]='\c[[44m'
ansi[lvioletbg]='\c[[45m'
ansi[lcyanbg]='\c[[46m'
ansi[whitebg]='\c[[47m'

file=""
line=""
str=""
ansi=""

# Create a temp file and ensure it's cleaned up on exit
TMPFILE=$(mktemp)
trap 'rm -f "$TMPFILE"' EXIT


cat > "$TMPFILE"

# collect all options and arguments
while [[ "$#" -gt 0 ]]; do
    case "$1" in
        line)
			shift
            line=$1
            shift
			style=$1
			shift
			sed -i ${line}'s/.*/'${ansi[$style]}'&'${ansi[reset]}/ "$TMPFILE"
            ;;
        str)
			shift
            str=$1
            shift
			style=$1
            shift
			n=$1
			shift
			sed -i -z 's/'$str'/'${ansi[$style]}'&'${ansi[reset]}'/'$n "$TMPFILE"
            ;;
        *)
            # not used at the moment a file can only be piped in
            #file=$1
            #shift
            blah="$@"
            echo -e "\033[31mError! Unknown text at the end of commandline: ${blah}\033[0m"
            exit
            ;;
    esac
done

cat "$TMPFILE"

Huh. I've noticed that the kind of writing that AI does is getting a bad name, and people are using "flags" to detect it, such as occurrences of semicolons, m-dashes, long sentences, marketing terms, restating something multiple ways (especially saying what something is followed by what it isn't), point lists, and some other traits.

It worries me that according to some of these "rules" my writing might be mistaken for stuff written by AI. I use semicolons and m-dashes quite a lot (though I tend to use two hyphens "--" instead of a proper m-dash "—" out of habit from the days before I learned how to enter an m-dash from the keyboard*). Also, I tend to write fairly long sentences with multiple parts, though I don't think I use marketing terms. And point lists. I detest over-use of point lists, though on occasion I will use them if they clarify and simplify what I'm writing, making it easier to read. To be clear, I don't write using AI. I sometimes use it to help me research stuff, but my writing comes from the neural net between my ears.

Another problem is that if people start adhering to these anti-AI writing rules we could see simplification of our language and the loss of complex thought. It's all rather pointless though, because people have already found ways to teach AIs to write more "normally" using style guides.

A friend, who I greatly respect as a writer and thinker, recently wrote a fairly long article on a complex topic. He used AI to help him research it, which he acknowledged in the credits, but the organisation he submitted it to rejected it as having been written by AI. This is disappointing. It was written by a highly literate human with assistance from AI. An important and informative article was discarded because of knee-jerk, anti-AI sentiment.

Recently there has been a proliferation of tools that supposedly detect AI writing, but nothing can reliably classify AI text that uses a style guide or a human with poor writing skills.

I intensely dislike "AI slop". Lazy people use it to churn out enormous amounts of text and video that is often meaningless, or pointless, or misleading clickbait. This is quite different from people who legitimately use AI to assist them in research, or to help them with inadequate English skills.

Hopefully this phase will pass soon. [sigh]

-----
* On Linux you can assign a "Compose" key. I've set it to the right-windows key, which in Linux is called the right-super key. I can type the m-dash by pressing the Compose key, releasing it, then pressing the "minus" key three times. On Linux this capability is very flexible and lets you extend it with your own definitions in addition to the couple of thousand characters defined by default.

I love science fiction. I've been reading SF since I was a very young kid in Primary School. I still read it almost every day. I enjoy SF movies and TV series, and I write SF stories. Even my artwork tends to have SF themes, as do the virtual worlds I've built too.

But we humans will never go to Mars, or the asteroids, or other star systems. We need to get used to that. Our machines will go, and they already are, but we can't. Humans are far too fragile. We can't survive the absent or low gravity, and the ferocious radiation for long.

On the Moon and Mars humans would have to spend their lives in underground tunnels. That's fine for me, I like the idea of living in small underground spaces, but I've never met anybody else who would like that.

But there is a worse problem: dust. On the Moon the dust is insanely abrasive and sticks to everything, and when it gets into your lungs it would be a quick path to lung cancer. It is almost impossible to get around that. On Mars the dust is even worse because it is also extremely toxic. How do you build underground dwellings without that dust getting into everything? You can't.

Yes, we will probably have research stations on the Moon occupied by small, rotating populations of scientists, but it will never really be a tourist destination for more than a tiny trickle of extremely wealthy people, who stay only a short enough time that they don't increase too much their risk of cancer from radiation damage.

Space is going to be explored by our machines, not us. We will be able to watch and vicariously enjoy and learn from those explorations, but never actually go there.

We need to concentrate our efforts on the one place in the universe that we know can support human life: Earth. Space industries can help us with that, but making Earth a better place should always be the goal.

For my own interest I've spent a large part of today looking into what AI models are available and how many of them are open source. To my very great surprise I found that of the 33 AI models I have listed in my AI folder where I record my interactions with AI, nearly two thirds of them (20) are open source models. This is wonderful! Even if the AI bubble does burst, nothing can prevent us from having access to AI tools.

One of the other things that surprised me was the variety of approaches being taken to AI, and how much creativity has been put into shoehorning enormous models into small computers. This is very encouraging. I love that some people are concentrating on text, others on images, others on 3D space, others on maths, others on coding.

We are approaching the time when this will all be available to us in a choice of single model that can fit on our phones without needing the internet.

Very exciting times ahead.

Last night I found a reference to first Century comedian and orator, Lucian of Samosata, as the writer of perhaps the first science fiction story, so I found his works on Project Gutenberg, including that story. Yay! I've now downloaded them for later reading.

Project Gutenberg is such a precious resource.

Sometimes AI is amazing... and other times, not so much. Here is a short, cautionary tale.

I recently installed an emulator for the TI-86 graphing programmable calculator. It's old and discontinued, but is very nice. I wish I'd had something like that when I was a kid. Kids today are so lucky. [sigh]

After running a cellular automaton program someone wrote for the TI-86, I wanted to understand how they'd written it, but the small screen shows just 21 characters across by 8 lines (128x64 pixels), so I had a look at the program file in a text editor on my desktop computer.

Not viewable.

Okay. I looked on the net for information about the format of TI-86 programs, but couldn't find any. I did find quite a few pages describing the file format of programs for the earlier TI-84 and TI-83, so figuring it would be similar I let the problem simmer for a while in my brain. (I often find this lets me come up with easy ways to solve problems.)

However, in this case, after about a day of turning the problem about in my mind, all I could see were ugly, brute-force approaches. I was sure there must be a more elegant approach, so I showed Claude AI the approach I'd been thinking of, and asked it how it would attack the problem.

It surprised me by telling me my approach would decode TI-83/84 programs, but not TI-86 ones, as they have an entirely different encoding scheme. I explained that I'd been unable to find a description of the TI-86 file format.

Claude AI asked me if I'd like it to write a program to decode it. Normally I prefer to do such things myself, but I was pushed for time, so I said yes.

It gave me a surprisingly long and complicated python program, which mostly worked, though there were some strange characters in the output. I figured I could clean it up myself.

I'm not keen on python. I used to write python programs years ago, but not much anymore, so I asked what approach it would use in writing an awk program to do the same thing.

It wrote one, which was much smaller than the python program, which is my usual experience with awk. This program had small problems too, but I figured I'd be able to fix that up pretty easily.

Well, I was trying to track down what some of these characters were by making a hexdump of the original file and I was astounded: the original TI-86 file is already in plain text!!!

It has a weird binary header that chokes any text editor, so I chopped off the header and the whole file could be read easily, except for a few odd characters. I replaced them and I had a simple, text listing of the cellular automaton program. Yay!

It took me just one line to do it:

tail -c +75 prog.86P | sed 's/\xd6/\n/g; s/\x1c/→/g; s/\x1a/−/g' >prog.txt

tail -c +75
cuts off the header of the file retaining everything from the 75th character onwards.

prog.86P
is the program to be decoded. The actual one I was wanting to see is named "CelAutom.86P".

|
pipes the output of the tail command into the next command, sed.

sed 's/\xd6/\n/g; s/\x1c/→/g; s/\x1a/−/g'
looks complicated, but it really isn't. It is really 3 small sed commands joined together using ";". The first part:

s/\xd6/\n/g
substitutes the hex value D6 (which is decimal 214) with the newline character (represented by \n). The g command tells sed to do this every time it encounters D6 on the line.

s/\x1c/→/g
substitutes the hex character 1C (decimal 28) with the arrow character "→". It probably doesn't need to be global, since there's unlikely to be more than one on a line, but I made it global just to be sure.

s/\x1a/−/g
substitutes hex character 1A with the negate character "−". This was a weird one. The TI-86 uses a different character to distinguish between minus (example: 3-2=1) and negate (example: the negative number −6). Do it globally.

So, there you have it. AI found me information on the net that I'd been unable to locate, but surprisingly didn't notice that the files I wanted to decode were pretty-much already in plain text. To be fair, I wasn't able to find the data online that it did, and I also failed to realise the program was plain text, until I used "hexdump -C" to look at it.

So AI is great, but at times also kinda stupid... like us.

Oh, and the cellular automaton image? You can see, below, an example for rule 30 (my favorite). It is a chaotic universe that self-generates from a single point.

(If the image is small, click on it to enlarge.)


The original image is at Zen Pencils
http://zenpencils.com/comic/118-roger-ebert-on-kindness/
by Gavin Aung Than, from Roger Ebert's original text.

The original essay by Roger Ebert that inspired the cartoon is at
http://www.salon.com/2011/09/15/roger_ebert/

I duplicate it here:

I do not fear death

I know it is coming, and I do not fear it, because I believe there is nothing on the other side of death to fear. I hope to be spared as much pain as possible on the approach path. I was perfectly content before I was born, and I think of death as the same state. I am grateful for the gifts of intelligence, love, wonder and laughter. You can’t say it wasn’t interesting. My lifetime’s memories are what I have brought home from the trip. I will require them for eternity no more than that little souvenir of the Eiffel Tower I brought home from Paris.

I don’t expect to die anytime soon. But it could happen this moment, while I am writing. I was talking the other day with Jim Toback, a friend of 35 years, and the conversation turned to our deaths, as it always does. “Ask someone how they feel about death,” he said, “and they’ll tell you everyone’s gonna die. Ask them, In the next 30 seconds? No, no, no, that’s not gonna happen. How about this afternoon? No. What you’re really asking them to admit is, Oh my God, I don’t really exist. I might be gone at any given second.”

Me too, but I hope not. I have plans. Still, illness led me resolutely toward the contemplation of death. That led me to the subject of evolution, that most consoling of all the sciences, and I became engulfed on my blog in unforeseen discussions about God, the afterlife, religion, theory of evolution, intelligent design, reincarnation, the nature of reality, what came before the big bang, what waits after the end, the nature of intelligence, the reality of the self, death, death, death.

Many readers have informed me that it is a tragic and dreary business to go into death without faith. I don’t feel that way. “Faith” is neutral. All depends on what is believed in. I have no desire to live forever. The concept frightens me. I am 69, have had cancer, will die sooner than most of those reading this. That is in the nature of things. In my plans for life after death, I say, again with Whitman:

I bequeath myself to the dirt to grow from the grass I love,
If you want me again look for me under your boot-soles.

And with Will, the brother in Saul Bellow’s “Herzog,” I say, “Look for me in the weather reports.”

Raised as a Roman Catholic, I internalized the social values of that faith and still hold most of them, even though its theology no longer persuades me. I have no quarrel with what anyone else subscribes to; everyone deals with these things in his own way, and I have no truths to impart. All I require of a religion is that it be tolerant of those who do not agree with it. I know a priest whose eyes twinkle when he says, “You go about God’s work in your way, and I’ll go about it in His.”

What I expect to happen is that my body will fail, my mind will cease to function and that will be that. My genes will not live on, because I have had no children. I am comforted by Richard Dawkins’ theory of memes. Those are mental units: thoughts, ideas, gestures, notions, songs, beliefs, rhymes, ideals, teachings, sayings, phrases, clichés that move from mind to mind as genes move from body to body. After a lifetime of writing, teaching, broadcasting and telling too many jokes, I will leave behind more memes than many. They will all also eventually die, but so it goes.

O’Rourke’s had a photograph of Brendan Behan on the wall, and under it this quotation, which I memorized:

I respect kindness in human beings first of all, and kindness to animals. I don’t respect the law; I have a total irreverence for anything connected with society except that which makes the roads safer, the beer stronger, the food cheaper and the old men and old women warmer in the winter and happier in the summer.

That does a pretty good job of summing it up. “Kindness” covers all of my political beliefs. No need to spell them out. I believe that if, at the end, according to our abilities, we have done something to make others a little happier, and something to make ourselves a little happier, that is about the best we can do. To make others less happy is a crime. To make ourselves unhappy is where all crime starts. We must try to contribute joy to the world. That is true no matter what our problems, our health, our circumstances. We must try. I didn’t always know this and am happy I lived long enough to find it out.

One of these days I will encounter what Henry James called on his deathbed “the distinguished thing.” I will not be conscious of the moment of passing. In this life I have already been declared dead. It wasn’t so bad. After the first ruptured artery, the doctors thought I was finished. My wife, Chaz, said she sensed that I was still alive and was communicating to her that I wasn’t finished yet. She said our hearts were beating in unison, although my heartbeat couldn’t be discovered. She told the doctors I was alive, they did what doctors do, and here I am, alive.

Do I believe her? Absolutely. I believe her literally — not symbolically, figuratively or spiritually. I believe she was actually aware of my call and that she sensed my heartbeat. I believe she did it in the real, physical world I have described, the one that I share with my wristwatch. I see no reason why such communication could not take place. I’m not talking about telepathy, psychic phenomenon or a miracle. The only miracle is that she was there when it happened, as she was for many long days and nights. I’m talking about her standing there and knowing something. Haven’t many of us experienced that? Come on, haven’t you? What goes on happens at a level not accessible to scientists, theologians, mystics, physicists, philosophers or psychiatrists. It’s a human kind of a thing.

Someday I will no longer call out, and there will be no heartbeat. I will be dead. What happens then? From my point of view, nothing. Absolutely nothing. All the same, as I wrote to Monica Eng, whom I have known since she was six, “You’d better cry at my memorial service.” I correspond with a dear friend, the wise and gentle Australian director Paul Cox. Our subject sometimes turns to death. In 2010 he came very close to dying before receiving a liver transplant. In 1988 he made a documentary named “Vincent: The Life and Death of Vincent van Gogh.” Paul wrote me that in his Arles days, van Gogh called himself “a simple worshiper of the external Buddha.” Paul told me that in those days, Vincent wrote:

Looking at the stars always makes me dream, as simply as I dream over the black dots representing towns and villages on a map.

Why, I ask myself, shouldn’t the shining dots of the sky be as accessible as the black dots on the map of France?

Just as we take a train to get to Tarascon or Rouen, we take death to reach a star. We cannot get to a star while we are alive any more than we can take the train when we are dead. So to me it seems possible that cholera, tuberculosis and cancer are the celestial means of locomotion. Just as steamboats, buses and railways are the terrestrial means.

To die quietly of old age would be to go there on foot.

That is a lovely thing to read, and a relief to find I will probably take the celestial locomotive. Or, as his little dog, Milou, says whenever Tintin proposes a journey, “Not by foot, I hope!”

Roger Ebert (18 June 1942--4 Apr 2013)

I've uploaded another short story -- a satire titled "Broke".
https://miriam-english.org/stories/short-stories/broke/broke.html
I hope it makes you smile.

I was just thinking some more about the difference between BASIC and awk, and how different our computing world would have been if our early personal computers had used awk instead of BASIC.

BASIC was first run in 1964 at Dartmouth College in UK, where it was created. (USA, not UK. My mistake. Sorry -- my crummy memory.)

UNIX was first created in 1971. It was just 16Kb in size.

In 1975 the Altair -- the world's first personal computer was released; it ran an absolutely minimal BASIC, just 4Kb in size. They later released a more capable version of BASIC, 8Kb in size.

The first TRS-80 was released in 1977, the same year awk was released inside AT&T Bell Laboratories. It wasn't until another year or two that awk was released world-wide as a part of Unix, and in 1988 the Free Software Foundation released gawk, which is today the most used version of awk.

The TRS-80 initially had a 4Kb BASIC, but later was upgraded to a more complete 12Kb BASIC.

The first Tandy Color Computer (CoCo) had an 8Kb BASIC. That was later upgraded to a 16Kb extended BASIC.

These are all still very small figures when compared to modern computer languages, which tend to be megabytes or even gigabytes in size.

So how big is gawk -- the most used version of version of awk?

It is about 3Mb on my 64-bit computer.

But that's a bit of an unfair comparison. Those earlier computers were 8-bit computers, not 64-bit. Also, the machine code was hand-written, whereas awk is written in C and compiled, which never creates code that's as efficient as a human can. (Though modern AIs might one day improve on that.)

So, how big might awk be if rewritten for an 8-bit computer? Well it just so happens that the Tandy CoCo was able to switch out its BASIC ROMs and run OS-9, which is a Unix-like operating system, and it has an implementation of awk (actually gawk) which is 36Kb in size -- a lot smaller, but it's still compiled from C. It makes me wonder how small it would be if hand-coded in assembler. Of course we will probably never know.

Would it be possible to make awk the operational language for a small, 8-bit computer? I don't know. It is difficult to imagine.

What a pity Unix/Linux/OS-9/flex... or some similar variant never took over the early 8-bit computer market. We might be so much further ahead of where we are now.

I do have to admit though, that the early Microsoft BASICs were masterful. They fitted tremendous functionality into extremely small spaces.

Recently I stayed up all night fiddling with a very cool little program that was explained in the Computer Recreations column of September 1986 issue of Scientific American.

My program was written in my current favorite computer language, awk, and used my graphics server which lets any computer language do graphics, even awk, which has no graphics commands.

#! /bin/awk -f

# hopalong
#
# by Miriam
# Friday 2026-04-24 01:36:14 am
# adapted from my CoCo program
# which was adapted from
# Scientific American, Computer Recreations (Sept '86)

# awk doesn't have abs() or sign() functions, but they're easy to add
function abs(num) {return num < 0 ? -num : num;}
function sign(num) {return num==0 ? 0 : num<0 ? -1 : +1;}

BEGIN{
    # Read canvas size
    "echo \"size\" | candraw" | getline
    wide = $1
    high = $2

    # clear the canvas
    print "clear"

    xv=yv=0
    loops=200000000
    a=-1000 ; b=0.1 ; c=-10
    reduction=0.05 ; soffset=-500

    for (n=1 ; n<loops ; n++) {
        x=(xv/reduction)+soffset
        y=(yv/reduction)+soffset
        if (x>0 && x<wide && y>0 && y<high) print "pset " x, y
        xx=yv-sign(xv)*(abs(b*xv-c))^0.5
        yy=a-xv
        xv=xx
        yv=yy
    }
}

The program is meant to be invoked as:
hopalong.awk | candraw
It pipes the print statements out to my graphics server through candraw, which acts as a bridge between the awk program and the server.

Here is the "hopalong.bas" program that I wrote in BASIC way back in 1986 for my Tandy Color Computer (CoCo):

1 ' adapted from Computer Recreations
2 ' Scientific American Sept. '86
10 XV=0:YV=0
20 LOOPS=600000
30 A=-1000:B=.1:C=-10
32 PMODE4,1:COLOR0,1:PCLS
34 SCREEN1,1
35 LINE(0,0)-(255,191),PSET,B
36 REDUCTION=.2:SOFFSET=128
40 FORL=1TO LOOPS
42 X=(XV/RED)+SOFFSET
44 Y=(YV/RED)+SOFFSET
46 IF X>255 OR X<0 OR Y>191 OR Y<0 THEN 60
50 PSET(X,Y)
60 XX=YV-SGN(XV)*(ABS(B*XV-C))^.5
70 YY=A-XV
80 XV=XX
90 YV=YY
100 NEXT
110 GOTO110

The awk program is so much clearer and easier to read. It amazes me that I learned anything in that dense BASIC language, but it is actually surprisingly capable. I still occasionally use a CoCo emulator and a TRS-80 emulator on my computer. Sometimes it is just easier.

It is funny to think that awk is so much more modern... it was initially released in 1977 -- the same year as the first Tandy TRS-80.