Encodes strings to the DEC Radix-50 encoding.

RADIX 50 is an uppercase-only character encoding created by Digital Equipment Corporation (DEC) for use on their PDP, and VAX computers. RADIX 50's 40-character repertoire (050 in octal) can encode three characters into one 16-bit word (PDP-11, VAX). It was also adapted for use on the Soviet PDP-11 clones, notably the Elektronika MK90 portable computer.

The actual encoding differs between the systems.

Learn more on the Wikipedia.

Add this line to your application"s Gemfile:

gem "dec_radix_50"

And then execute:

$ bundle install

Or install it yourself as:

$ gem install dec_radix_50

DECRadix50.encode(charset, string [, replace_char]) => Array<Integer>

• charset: character set, should be 40 characters long for the DEC RADIX-50. The charset string length defines the base.

  The gem comes with two predefined characters sets:

  # Elektronika MK90 filenames charset:
  MK90_CHARSET = " ABCDEFGHIJKLMNOPQRSTUVWXYZ$./0123456789"
  
  # RT-11 filenames charset:
  RT11_CHARSET = " ABCDEFGHIJKLMNOPQRSTUVWXYZ$%*0123456789"

• string: string to encode.

• replace_char: replaces unsupported characters in the input string. Should be included in the charset. Default value is " " (a space).

• Array of integers.

require "dec_radix_50"

DECRadix50.encode(DECRadix50::MK90_CHARSET, "ABCDEF")
# => [1683, 6606]

DECRadix50.decode(charset, encoded_values) => String

• charset: character set, should be 40 characters long for the DEC RADIX-50. The charset string length defines the base.

• encoded_values: array of integers that represent an encoded string.

• String.

require "dec_radix_50"

DECRadix50.decode(DECRadix50::MK90_CHARSET, [2092, 1015, 34_320, 3259, 8001, 29_000, 3412, 24_567, 815, 859, 0])
=> "ALL YOUR BASE ARE BELONG TO US   "

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/8bit-mate/dec_radix_50.rb.

The gem is available as open source under the terms of the MIT License.