NABU BBS Terminal  v1.02.17
===========================

ANSI BBS telnet terminal for the NABU Personal Computer.
Connect to ANSI BBS systems via the RetroNET Internet Adapter.


TWO BUILDS -- PICK THE RIGHT ONE
---------------------------------

  NABUTERM.nabu
    40 columns, per-character ANSI colour.
    Any NABU PC (stock TMS9918A).

  NABUTERM80.nabu
    80 columns, single global colour.
    F18A or compatible FPGA upgrade required.

Both builds have the same features. Use NABUTERM80.nabu if you have an
F18A or similar upgrade -- ANSI art designed for 80 columns is much easier to read.
Use NABUTERM.nabu on stock hardware.

The 40-column build uses the TMS9918A's Graphics II mode to render
per-character ANSI colour on stock hardware. BBS content designed for 80
columns is displayed in a scrollable 80-column virtual buffer -- use the
arrow keys to pan.


LOADING
-------

Copy the appropriate .nabu file to your IA file store. Load it from the
NABU boot menu the same way as any other NABU application.


MAIN MENU
---------

The preset menu appears on startup and after every disconnect.

  [1-5]  Connect to that preset. If the slot is empty you will be
         prompted to enter a hostname and port first.

  [E]    Edit a preset slot -- enter hostname then port number.
         Press Enter on a blank port line to keep the existing port.
         Press ESC at the hostname prompt to cancel without saving.

  [D]    Delete a preset slot.

  [Q]    Quit -- returns the NABU to the boot loader.

Presets are saved to NBTERM.CFG on the IA file store and survive power
cycles. Default port is 23 (standard telnet). Five slots available.


IN SESSION
----------

A brief key-reference line is printed when the connection opens.
Press SYM at any time for the full key reference overlay.

  Controls -- both builds:

    CTRL-]       Disconnect and return to the main menu.
    CTRL-E       Toggle local echo override. Use this when a BBS sends
                 no echo and your typing is invisible.
    SYM          Show key reference overlay. Any key dismisses it.

  Controls -- 40-column build only:

    Left/Right arrows    Scroll the viewport left or right by one column.
    Page Left/Right      Scroll the viewport left or right by 8 columns.

  Controls -- 80-column build only:

    CTRL-T       Cycle text colour through a preset list.

  Key mapping:

    Backspace and Enter are mapped correctly for telnet NVT.
    The full CP437 character set is loaded at startup -- box drawing,
    block graphics, and extended characters all render correctly.


ZMODEM FILE RECEIVE
-------------------

Transfers start automatically when the BBS initiates one -- nothing to
do on your end. Progress is shown on screen:

    ZModem Receive
      FILENAME.EXT (42 KB)
        Received: 12345 bytes
      ...
      Complete: 43008 bytes

Received files are written to the IA file store under the filename the
sender provides. If a transfer stalls or you need to abort, press CTRL-]
to disconnect.

Tested against AmiExpress (Amiga BBS) and Mystic BBS on real NABU
hardware.


KNOWN LIMITATIONS
-----------------

  - ZModem send is not implemented. Receive only -- the NABU cannot
    initiate an upload.

  - 80-column build: no per-character background colour. F18A (and
    similar) TEXT80 mode uses a single global colour register. All text
    renders on black regardless of ANSI colour codes. The 40-column
    build does not have this limitation.

  - 80-column build requires F18A or similar upgrade. NABUTERM80.nabu
    will not run on stock TMS9918A.