SET-UP D - Multinational Character Set, NRCS, International Keyboards, Personalities (enhancement)

Background

The SET-UP D screen is an enhancement that the VT132 adds to the original VT100 functionality.

The VT132 implements multinational character support (derived from the VT220), international keyboard support and personality support for a range of other terminals of the era (available from the FabGL library), these features are accessible and configurable through theSET-UP D screen.

SET-UP-D-MCS

Help

The integrated help screen is accessible by pressing the F1 key as with the other SET-UP screens, provides a summary of the features that are configurable on this screen.

SET-UP-D-HELP

DEC Multinational Character Set (MCS 8-bit) Support

The DEC Multinational Character Set (MCS) is the default character set on the VT132. It provides:

  • a standard 7-bit ASCII character set
  • an extended 8-bit ASCII character set including accented characters, currency symbols, and other character glyphs missing from 7-bit ASCII
  • (and is the ancestor of the ISO 8859-1 'Latin 1' codepage)
  • a full MCS 8-bit character set available to all applications that are 8-bit clean

DEC National Replacement Character Set (NRCS 7-bit) Support

The DEC National Replacement Character Set (NRCS) is an alternate character set on the VT132. It is mutually exclusive with the MCS. It provides:

  • a standard 7-bit US-ASCII character set, with
  • a maximum of 12 standard US-ASCII characters substituted with language/country specific characters for a nominated country
  • (currently implemented for UK (British), DE (German) and IT (Italian) on the VT132, with more countries to follow)
  • international character support for applications that are not 8-bit clean and that only support 7-bit ASCII

The UK is the simplest of these with only the pound symbol £ substituted for the US-ASCII # symbol at ASCII 35 (dec) or 0x24 (hex).

For other countries/languages, see the reference above to see which characters are substituted.

WARNING

Only one country can be active for NRCS at a time. Changing the country will appear to change the contents of files created while working with another country, because the same 7-bit ASCII code is used to represent different characters depending on the country currently selected.

International Keyboard Support

PC keyboard scancode to character set mappings are provided for the same country/languages that the VT132 currently support with NRCS (see next section).

Selecting character set and keyboard support

Pressing 7 on the keyboard toggles between the two available character set modes

  • DEC Multinational Character Set (MCS 8-bit), and
  • DEC National Replacement Character Set (NRCS 7-bit)

Pressing 6 on the keyboard selects the country/language for both NRCS mode and keyboard support, based on the current cursor position. Current choices are:

  • US
  • UK
  • DE (German)
  • IT (Italian)

Moving the cursor left or right with the <left> and <right> cursor control keys, <tab> or <cr> enables you to choose the language/country you want to select.

The current country/keyboard as a word eg. German on the last line of the screen.

WARNING

NRCS country/language selection and keyboard country/language selection are not independent. On the VT220 the country/language selection was made automatically by the keyboard that was attached to the terminal. At least with the VT132 you get to choose.

Personality Support

The FabGL library with which the VT132 is built provides a number of 'Personalities' for different terminals of the era.

It maps the escape sequences that control these terminals to the equivalent escape sequences for the VT100.

The special, non-ASCII keyboard keys (mainly cursor control keys) are mapped to the typical "WordStar" key mappings. Details tba.

The available personalities are:

  • ANSI/VT100 (the default VT100 operating mode)
  • WordStar/VT100 (same as above but with WordStar cursor navigation key mappings)
  • ADM-3A
  • ADM-31
  • Hazeltine 1500
  • Osborne 1
  • Kaypro
  • VT52 (already a feature of the VT100, this personality simply actives VT52 compatibility mode)

Selecting personality support

Pressing the <up> and <down> cursor control keys cycles to the Previous or Next personality in the list.

SET-UP D - advance to next setup screen

On the SET-UP D screen, pressing 5 will return to the SET-UP A screen.

Last Updated: 7/26/2020, 4:33:44 PM