Miscellaneous Notes

Limitations of Qaop/JS

Qaop/JS is terrific and allows you to make and save changes to code easily. One problem I've encountered, though, is that to insert the not equals symbol (<>) in BASIC, you need to enter what is referred to as Symbol Shift w. Symbol shift is actually the ctrl key on a PC keyboard and ctrl-w has the unfortunate effect of closing the (Chrome) browser window! Before discovering Fuse, I just coded around this, somewhat clumsily.

A note on re-numbering BASIC programs

When first entering code using Sinclair BASIC, line numbers start at 10 and are incremented by 10 each time. If you want to insert a new line between consecutive lines 90 and 100 say, you can just create new lines in the range 91 to 99. However, after doing this several times to the same section of code, you can run out of free line numbers and have to move (i.e. copy and delete) adjacent lines first. It's not a very elegant method and you have to keep an eye out for line numbers use in GOTO and GOSUB statements . IIRC in the 1980s, I had the OCP Master Toolkit, which provided an automatic renumbering feature among many others and I've started using it again. It's is bit of a faff, but well worth it as the resulting code looks much neater.

I renumber the lines using the following method:

• in Fuse, save BASIC program to tzx tape file

• save tzx file to disk file

• run Master Toolkit in new Fuse session

• load BASIC tzx file

• enter MT code and renumber BASIC pgm (using r key)

• exit MT

• save BASIC program to new tzx tape

• save tzx file to new disk file

• open tzx file in new Fuse session

• load any machine code

• save z80 image file

Apparently, there were two versions of the OCP MT - one for 16k machines and one for 48k ones. I need the latter, but am not sure that I'm not using the former! However, with two related exceptions, it seems to work fine. Those exceptions are my Orbits program and the Orbits-derived Lagrange Points program, which seem to result in a meltdown by the MT! I'm not really sure what to do when the line numbers are zero, as reported below (renumbering Orbits). Unfortunately, the MT either freezes after a while, or won't let me stop scrolling, so there is nothing to be done but to close it.