Horizontal shift is now complete.

This is the last of the quick and easy parts of the code.

From now on the distance between uploads could be high as HW will be needed.
This has to be ludicrously simple so as to be built by a 10 year old.

The next upload will be the frequency counter needed for two parts of this
project. However this is a while away yet so now to desribe the X shift control.
(I WILL post a fully working Python version of a frequency counter I wrote ages
ago that uses /dev/dsp.)

Horizontal shift, from the cammand line window type:-

HSHIFT<CR>

Using the keys r, R, l, L, and Q or q change the position of the scan like this:-

r shifts scan to the right by one scan size, (64 bytes).
R shifts scan to the right by one byte at a time.
l shifts scan to the left by one scan size, (64 bytes).
L shifts scan to the left by one byte at a time.
Q or q exits this mode.

The keys respond like INKEY$ in BASIC...
No user values are changed except switching from real grab to rescan mode.
The TB speed will always be the fastest available although it could be made
variable if so desired. I decided against it as this is useful for searching
for odd wavefronts. The status line will let you know where in the file the
start of the current scan is...

Enjoy...

P.S. In the process of building a simple, starter, Y amplifier input ATM...
Also the script is about 38KB in size now...