From 419ba412758692661188591e1d883c0f4489d8f3 Mon Sep 17 00:00:00 2001
From: sejo <tejocote+codeberg@posteo.net>
Date: Thu, 15 Jul 2021 21:14:02 -0500
Subject: [PATCH] forth page

---
 src/forth.gmo     | 52 +++++++++++++++++++++++++++++++++++++++++++++++
 src/low-level.gmo |  1 +
 src/tw.txt        |  1 +
 src/uxn.gmo       |  7 +++----
 4 files changed, 57 insertions(+), 4 deletions(-)
 create mode 100644 src/forth.gmo

diff --git a/src/forth.gmo b/src/forth.gmo
new file mode 100644
index 0000000..47c9e6e
--- /dev/null
+++ b/src/forth.gmo
@@ -0,0 +1,52 @@
+# forth
+
+stack-based and lightweight programming language.
+
+it uses the {postfix} notation.
+
+# reading
+
+this book has a great pace and nice illustrations
+
+=> https://www.forth.com/starting-forth starting forth book
+
+# some words
+
+## running words
+
+these are some words for doing arithmetic with paces (min/km) and velocities (km/hr)
+
+``` forth words
+: ms>s swap 60 * + ; ( min segs -- segs )
+: hms>s ms>s swap 3600 * + ; ( hr min segs -- segs )
+: msd>s1k >r ms>s 1000 swap r> */ ; ( min segs metros -- segs1km )
+: paso>vel ms>s s1k>vel ; ( min segs -- vel )
+: s1k>vel 3600 swap / ; ( segs1km -- vel )
+: vel>s1k 3600 swap /  ; ( vel -- segs1km )
+: .min 0 <# [CHAR] ' HOLD #S #> TYPE ; ( min -- )
+: .seg 0 <# [CHAR] " HOLD # # #> TYPE ; ( segs -- )
+: .ms 60 /mod .min .seg ; ( segs -- )
+: .vel . ." km/hr " ;
+: lista-velocidades cr 21 10 do i dup . vel>s1k .ms cr loop ;
+```
+
+for example, to convert a velocity to a pace, and print it:
+
+``` input: 18, output: 3'20"
+18 vel>s1k .ms 
+3'20" ok
+```
+
+to do the opposite operation:
+
+``` input: 3 20, output: 18 km/hr
+3 20 ms>s s1k>vel .vel
+18 km/hr ok
+``` 
+
+to get the pace of a given segment, using minutes, seconds and distance in meters:
+
+``` input: 1 03 300, output: 3'30"
+1 03 300 msd>s1k .ms
+3'30" ok
+```
diff --git a/src/low-level.gmo b/src/low-level.gmo
index a19b6db..fcaf88e 100644
--- a/src/low-level.gmo
+++ b/src/low-level.gmo
@@ -8,6 +8,7 @@ writing code closer to the machine(s)
 
 # software
 
+=> ./forth.gmi {forth}
 => ./uxnería.gmi {uxnería}
 => ./nibble_dice_tracker.gmi {nibble dice tracker}
 => ./darena.gmi {darena}
diff --git a/src/tw.txt b/src/tw.txt
index a288222..27c42aa 100644
--- a/src/tw.txt
+++ b/src/tw.txt
@@ -2,6 +2,7 @@
 # url = https://compudanzas.net/tw.txt
 # url = gemini://compudanzas.net/tw.txt
 #
+2021-07-15T12:00:00-05:00	reading starting {forth}. possible practice, puzle, game, eventually dance?
 2021-07-12T12:00:00-05:00	published the {uxnería} repo for {uxn} projects and sketches. excited about the {nibble dice tracker}!
 2021-07-05T21:00:00-05:00	for the fourth session of the workshop we shared our máquina universal bailable {mub} - it was great to revisit it!
 2021-06-30T21:00:00-05:00	in the third session of the workshop we learned and performed the {danzasistemas-tag} (first time ever!) and a turing machine in {d-turing} mode
diff --git a/src/uxn.gmo b/src/uxn.gmo
index 33c901d..a8c9026 100644
--- a/src/uxn.gmo
+++ b/src/uxn.gmo
@@ -1,6 +1,6 @@
 # uxn
 
-uxn is a little forth machine with 32 instructions.
+uxn is a little {forth} machine with 32 instructions.
 
 => https://wiki.xxiivv.com/site/uxn.html uxn
 
@@ -8,11 +8,10 @@ it uses the {postfix} notation.
 
 our projects and sketches are hosted in the {uxnería}
 
-# notes
 
-## common code structures
+# common code structures
 
-### loop with a counter
+## loop with a counter
 
 loop with a structure that allows you to easily use the iteration counter: