hex="A B C D E F"; for cp in cp850 cp437; do echo "code page: $cp;"; for l in $(seq 3 9) $hex; do echo -n "(#$l)  "; for col in $(seq 0 7); do echo -en "\x$l$col "; done;echo -n " "; for col in 8 9 $hex; do echo -en "\x$l$col "; done; echo; done | iconv -f $cp -t utf-8; echo; done

code page: cp850;
(#3)  0 1 2 3 4 5 6 7  8 9 : ; < = > ? 
(#4)  @ A B C D E F G  H I J K L M N O 
(#5)  P Q R S T U V W  X Y Z [ \ ] ^ _ 
(#6)  ` a b c d e f g  h i j k l m n o 
(#7)  p q r s t u v w  x y z { | } ~  
(#8)  Ç ü é â ä à å ç  ê ë è ï î ì Ä Å 
(#9)  É æ Æ ô ö ò û ù  ÿ Ö Ü ø £ Ø × ƒ 
(#A)  á í ó ú ñ Ñ ª º  ¿ ® ¬ ½ ¼ ¡ « » 
(#B)  ░ ▒ ▓ │ ┤ Á Â À  © ╣ ║ ╗ ╝ ¢ ¥ ┐ 
(#C)  └ ┴ ┬ ├ ─ ┼ ã Ã  ╚ ╔ ╩ ╦ ╠ ═ ╬ ¤ 
(#D)  ð Ð Ê Ë È ı Í Î  Ï ┘ ┌ █ ▄ ¦ Ì ▀ 
(#E)  Ó ß Ô Ò õ Õ µ þ  Þ Ú Û Ù ý Ý ¯ ´ 
(#F)  ­ ± ‗ ¾ ¶ § ÷ ¸  ° ¨ · ¹ ³ ² ■   

code page: cp437;
(#3)  0 1 2 3 4 5 6 7  8 9 : ; < = > ? 
(#4)  @ A B C D E F G  H I J K L M N O 
(#5)  P Q R S T U V W  X Y Z [ \ ] ^ _ 
(#6)  ` a b c d e f g  h i j k l m n o 
(#7)  p q r s t u v w  x y z { | } ~  
(#8)  Ç ü é â ä à å ç  ê ë è ï î ì Ä Å 
(#9)  É æ Æ ô ö ò û ù  ÿ Ö Ü ¢ £ ¥ ₧ ƒ 
(#A)  á í ó ú ñ Ñ ª º  ¿ ⌐ ¬ ½ ¼ ¡ « » 
(#B)  ░ ▒ ▓ │ ┤ ╡ ╢ ╖  ╕ ╣ ║ ╗ ╝ ╜ ╛ ┐ 
(#C)  └ ┴ ┬ ├ ─ ┼ ╞ ╟  ╚ ╔ ╩ ╦ ╠ ═ ╬ ╧ 
(#D)  ╨ ╤ ╥ ╙ ╘ ╒ ╓ ╫  ╪ ┘ ┌ █ ▄ ▌ ▐ ▀ 
(#E)  α ß Γ π Σ σ µ τ  Φ Θ Ω δ ∞ φ ε ∩ 
(#F)  ≡ ± ≥ ≤ ⌠ ⌡ ÷ ≈  ° ∙ · √ ⁿ ² ■   

# locale; export LANG=C; export LANG=de_AT.iso8895-15; LANG=pt_BR.UTF-8; // iconv --to ??: 
# ~~~ set the timezone across reboots  ~~~
> find /etc/ -type l | xargs ls -l | grep zone
lrwxrwxrwx 1 root root 33 Mär 14  2022 /etc/localtime -> /usr/share/zoneinfo/Europe/Vienna
> su;  # change to ›superuser/root‹; you will need a password; many linux boot-cds allow: »sudo su«
> ln -fs /usr/share/zoneinfo/Europe/Lisbon /etc/localtime
# ~~~ change the time zone temporarily ~~~
> tzselect; TZ='Europe/Vienna'; export TZ;
> date; date --utc;
Di 05 Aug 2025 04:03:38 CEST
Di 05 Aug 2025 02:03:38 UTC

# ~~~ usage of your serial RS232 port COM1 / usage of your printer at the parallel cable LPT1 ~~~
DOS:   type myfile.txt >COM1
Linux:   cat myfile.txt >/dev/ttyS0
Linux/Wine, I don´t know about DosBox/Linux (uses virtual 86 mode): 
> ls -l ~/.wine/dosdevices/
c: -> ../drive_c
com1 -> /dev/ttyS0
lpt1 -> /dev/lp0
# serial RS232 cables were typically used to connect a 64K modem that connected to the internet or another computer via the landline phone line
# serial RS232 cables were also used directly between two computers, called null modem cables, like a crossover ethernet cable RJ45
stty -F /dev/ttyUSB0 speed 1200 raw; stty -F /dev/ttyUSB0 -cmspar cs8 parenb oddp cstopb inpck parmrk; stty -F /dev/ttyUSB0 --all | grep -Eo ".par[^ ]*|.oddp|.evenp|.cs[78]|.cstopb|.inpck|.parmrk";
stty -F /dev/ttyUSB0 speed 9600 cooked; stty -F /dev/ttyUSB0
> cat /dev/ttyS0 >myfile.txt  # at the other end of the cross-over RS232 cable connecting two computers
Linux:  lrzsz
DOS: txzm (https://www.bttr-software.de/freesoft/comm1.htm)
Linux: picocom / minicom / cutecom, Linux ADSL internet: pppd - point to point tunneling protocol
DOS: procomm       # sending AT commands at dos, AT commands can dial a phone number, there are two signalling modes/ways to convert a phone number into sound as sent over a landline phone connection
Linux: telnet
DOS: telemate (http://www.starbase21.net/telemate.html), Windows: ¿putty?

#  utf-8 uses multi-byte characters for all non-ascii chars (ascii: first 128/7bit) // cp850 & cp437 use one byte per character
# #255/chr(255) can effectively be used as special, invisible space character and as a »no-line-breaking-space«
> echo -n $'==\xFF==' | iconv -f cp850;      // --> == ==
> { echo -en "\xFF = " | iconv -f cp850; h2t "-&nbsp;-"; } | txtfmt 
> { echo -n $'\xFF = ' | iconv -f cp850; h2t "-&nbsp;-"; } | txtfmt  --oct
#194;#160; = - -#10;       # new line: character number 10, chr(10), which is a 12 in the octal number system, also written as "\n"
\302\240 = - -\012
> grep thinsp ~/elstel/uploads/wngklu/htsyms.txt; | txtfmt --oct
thinspace: '\342\200\211', no-break-space: ' ', shy:
> echo -n $'\342\200\211' | txtfmt --oct;   # This is a program written by me, you dont have that at Linux, use »od -An -txC -toC -c«.
\342\200\211<EOF>
# .html: <span style="white-space:nowrap">This is a long text guaranteed to always stay on the same line.</span>

h2t() { echo "$@" | w3m -O utf-8 -T text/html -dump; }
# The lines #3..#7 belong to the ascii code, which is only 7bit or 128 characters, upper half are extensions
> echo -en "\xD5 = " | iconv -f cp850; h2t "&inodot;";
ı = ı
ei() { echo -n "&inodot;&#$i; "; }; es() { echo -n " / "; }; h2t "$(for i in 769 768 771 770 780 807; do ei $i; done; es; for i in 772 775 778; do ei $i; done; es; for i in 7624 7625 7620 7621 7622 7623; do ei $i; done; echo " / i&#807;"; )"
ı́ ı̀ ı̃ ı̂ ı̌ ı̧ / ı̄ ı̇ ı̊ / ı᷈ ı᷉ ı᷄ ı᷅ ı᷆ ı᷇ / i̧