Hi mark_s,

The data, as read by Readcode are organized in bytes, not in words and declared by DB instructions .
For example, this is a line from the data tables :
DB 67, 67, 82, 67, 66, 67, 65, 67, 66, 81, 65, 66, 64, 63, 62, 61

So the increment must be 1 , not 2.

Sorry, but the example you give is a simple polling program, not synchronized by any interrupt.
This example does not address the issue I raised : How to handle the fact that ReadCode (or any Basic instruction) is restarted again and again by high rate interrupts instead of terminating ?

MikeBZH