https://github.com/8bit-mate/dec_radix_50.rb
Encodes strings to the DEC Radix-50 encoding.
https://github.com/8bit-mate/dec_radix_50.rb
dec digital-equipment-corporation pdp-11 pdp11 radix-50 retrocomputing string-encoding text-encoding vax
Last synced: 2 months ago
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Encodes strings to the DEC Radix-50 encoding.
- Host: GitHub
- URL: https://github.com/8bit-mate/dec_radix_50.rb
- Owner: 8bit-mate
- License: mit
- Created: 2024-01-02T15:49:52.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2024-01-31T20:58:39.000Z (over 1 year ago)
- Last Synced: 2024-01-31T21:44:57.980Z (over 1 year ago)
- Topics: dec, digital-equipment-corporation, pdp-11, pdp11, radix-50, retrocomputing, string-encoding, text-encoding, vax
- Language: Ruby
- Homepage:
- Size: 8.79 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE.txt
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README
# dec_radix_50.rb
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](https://en.wikipedia.org/wiki/DEC_RADIX_50).
## Installation
Add this line to your application"s Gemfile:
```ruby
gem "dec_radix_50"
```
And then execute:
$ bundle install
Or install it yourself as:
$ gem install dec_radix_50
## Usage
### Encoding
DECRadix50.encode(charset, string \[, replace_char\]) => Array\
### Arguments
+ **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:
```Ruby
# 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).
### Returns
+ Array of integers.
### Example:
```ruby
require "dec_radix_50"
DECRadix50.encode(DECRadix50::MK90_CHARSET, "ABCDEF")
# => [1683, 6606]
```
### Decoding
DECRadix50.decode(charset, encoded_values) => String
### Arguments
+ **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.
### Returns
+ String.
### Example:
```ruby
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 "
```
## Development
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](https://rubygems.org).
## Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/8bit-mate/dec_radix_50.rb.
## License
The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).