This is one for the upstream component, but you probably know how to pass it on.

My FORTH for Agon uses RST.LIL in 16-bit mode (ADL=0) and this is rejected by the eZ80 interpreter. The hardware just works. There may be other programs that refuse to run just because the wrong instruction suffix (in fact a prefix byte in the binary machine code) is used on RST.

The current logic to convert the keycode in case the SHIFT key is pressed does not work for most symbols. There is probably a better way to obtain the ASCII code from a key in SDL that does not depend on the keyboard layout.

I'm less than happy with the way the entire canvas is re-rendered each frame from the text data. As soon as we add line drawing and whatnot, we cannot store the parameters of all lines drawn and re-render them each time. Think of the triangles.bas demo that keeps drawing triangles indefinitely, where each triangle overwrites parts of previous ones.

So I would like to draw all characters, lines etc. onto one 'surface' (which may or may not be the window's own canvas) and then possibly blit this into the window's canvas each frame. This way we may be able to draw sprites on top of this when we get to that (or the cursor possibly). When scrolling we move part of the 'surface' using an appropriate blit function. Characters can be drawn by plotting each pixel (first clear the rectangle to the background colour). The real Agon hardware draws each character as a bitmap into the frame buffer. When you update a character in the font using VDU 23, future instances will be redrawn with the updated pattern, but previously drawn characters will stay as-is.

I'm less than happy with the way the entire canvas is re-rendered each frame from the text data. As soon as we add line drawing and whatnot, we cannot store the parameters of all lines drawn and re-render them each time. Think of the triangles.bas demo that keeps drawing triangles indefinitely, where each triangle overwrites parts of previous ones.

So I would like to draw all characters, lines etc. onto one 'surface' (which may or may not be the window's own canvas) and then possibly blit this into the window's canvas each frame. This way we may be able to draw sprites on top of this when we get to that (or the cursor possibly). When scrolling we move part of the 'surface' using an appropriate blit function. Characters can be drawn by plotting each pixel (first clear the rectangle to the background colour). The real Agon hardware draws each character as a bitmap into the frame buffer. When you update a character in the font using VDU 23, future instances will be redrawn with the updated pattern, but previously drawn characters will stay as-is.

Thank you for creating this emulator! I'm loving it!

It can be quite confusing to get the correct version of BBC Basic from other repos...

Pleas add the version working with the current state of the emulator as you did for MOS.bin

Still not complete: CIRCLE (ugly polygon outline), TRIANGLE (only outline not filled). MOVETO, plot dot, line work OK. Also implemented character bitmap redefine with VDU 23,, grafix origin with VDU 29

Hi,

great work with the Agon emulator, it looks great for now and I was able to build it without problems on my MacBook Pro M1. I noticed that after a few minutes of usage my Mac gets super hot and I have to stop the emulator. Any idea what could cause this problem ? (BTW, same problem with the emulator built in debug and release mode)

Thanks, Jean