development tools • Re: BeebEm Custom Keyboard Mapping

This is the problem I'm trying to solve, typing tilde, '~'
So, Caret '^' and Tilde are on the same key.
And on a regular keyboard Caret is Shift-6 and on mine Tilde is Shift-#
I've mapped PC-Shift to BBC-Shift (it was unmapped for some reason??)
And then I think you're supposed to click BBC-^ and then check shift, followed by check shift and PC-#?
But when I go back to the Beeb and press PC-Shift-6 in types an up arrow?!?!
And if I press PC-Shift-# I get the divide symbol!!

You almost certainly are using MODE 7; which uses a slightly different character set, generated by the SAA5250 Teletext character generator IC, from the legends on the keyboard, but also requires only one byte to store the character code at each screen position. MODEs 0 to 6 use Acorn's own graphics hardware to generate the display; but in these modes, the colour of every individual pixel is stored separately, which swallows up more memory.

In MODE 7, an opening square bracket [ displays as a left arrow, a backslash \ displays as 1/2, a closing square bracket displays as a right arrow, an exclusive-or sign ^ (which the BBC actually takes to mean **; the exclusive-or operator is EOR) displays as an up arrow; an opening posh bracket { displays 1/4, a vertical bar | displays as a double vertical bar, a closing posh bracket } displays as 3/4 and a tilde ~ displays as a calculator division sign ÷ .

Type MODE 6 for a display mode that will match the key legends (but be aware this will use up 8KB for the screen, as opposed to 1KB in MODE 7).

As far as the computer is concerned, the characters have the same meaning irrespective how they be displayed.

Statistics: Posted by julie_m — Sat Mar 02, 2024 10:25 am

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