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BeeBS
The BBS designed for the BBC Micro
Updates
Teletext AND ANSI?!
6 February 2024 Updates
Now that there is an easy way to access BeeBS in a Mode 7 supported web
client, I felt I should really make the most of the opportunity and add
the ability for OBBS to send full Mode 7 menus. I was initially using
BGET to read each byte of the menu frame, however this resulted in a
single frame taking 5 seconds to load. After asking for a little help
over at the Stardot forums I was presented with two main options to speed
things up.
The fastest option was to use DIM to reserve a block of memory (...say the
size of a teletext frame) and then LOAD the teletext frame (or in this
case menu file to that location), using VDU to display each byte. This
resulted in a frame being sent in less than 2 seconds at 9600 baud.
Unfortunately OBBS is still setup to use Mode 7 on a BBC Micro (Model B)
and so doesnb t have the head room to reserve 1kb.
The second option was to use a buffer (which can be as low as 10 bytes)
for speed improvements. I experimented with various buffer sizes and found
that 256bytes to 512bytes was almost as fast as using LOAD. This is the
choice I opted for.
I realized that it would be a good time whilst Ib m making these changed
to add ANSI support to OBBS. Adding ANSI support was relatively
simple...getting OBBS to save the users preference for ANSI in-between
sessions however, was not! Data within the user file is accessed via BGET
and PTR so the settings need to be saved within the current data
structure. Luckily OBBS stores some user preferences in a user flag which
is 8 bits long (1 byte) of which only the 3 bits are used.
0000 0001 - Supports Lower Case
0000 0010 - Requires Linefeeds
0000 0100 - Supports Colour (Mode 7)
All I needed to do was to store the ANSI support in bit 4:
0000 1000 - Supports ANSI
This byte is stored in the variable ff%, from the value of ff% BeeBS can
set the menu folder to the appropriate location (Mode 7 menus are stored
in the V directory and ANSI in 8).
As it stands selecting ANSI overrides all other options (colour, linefeeds
and uppercase only) however this shouldnb t be a problem as Ib m not aware
of any ANSI terminals that donb t support lowercase! The last bit of magic
was to use the value of ff% to determine if control codes need to be
filtered, and hey presto...
Loading an ANSI page takes around 4 seconds so I have opted for 60 column
pages instead of 80.
A rather inelegant solution but is a working fix for now. BBS of the time
would ask the user at the outset what type of terminal they are using (or
ask for a key press, from which the host could deduce the terminal type).
Created on my Acorn BBC Master 128
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