A few things to note; the subroutine starts at 0C60; if you have
a Bits & PC’s graphics board, put E0 at 0C62. You can also load
register C with the character of your choice and call 0C6D. Fun,
isn’t it? (It seems to impress non-computer owners, too). Keen
users of disassemblers will find some very interesting instructions
mixed in with the well-known ones.
I must have been typing E 0C50NL for over a year now, and nobody
told me that the E command will’ pick up three addresses, if they
are there, If you type E 0C50 0C60 0C70 the program at 0C50
will be executed as normal, but all three “addresses are in the
scratchpad RAM, available for use by the program. The 0C60 would
be at ARG 2 (0C0E/F) and 0C70 at ARG 3 (0C10/1). This would be
useful if you had a program you wanted to run repeatedly, with
varying parameters, and couldn’t be bothered to put a proper keyboard
input routine in, or hadn’t enough memory to do so.
A NEW MAGAZINE WORTH TEN POUNDS!
The first edition of the Liverpool Software Gazette has arrived at
Zilog Villas; it is produced by Microdigital, and is well worth
investigation. For a start, they have included a listing of their
own Nascom programming language, M5. This is normally sold for
ten pounds, so you save nine pounds fifty on the first issue!
There is also an article about running Sargon on a Nascom, which I
expect will come in handy when I get around to translating all those
funny TDL mnemonics. There was also a short article on the text
oriented language, Pilot, which has given me an idea for what to
write next to perplex poor Marvin. Obviously, a Nascom Pilot
interpreter.... Yet another setback for the heap of half finished
programs in my possession. (An example of this is the program
suggested by Richard Beal, to test/convert programs intended for
other machines; to tell the truth though, all I had done was draw
a circle and write “start” in it....)
AN IDEA FOR A PROGRAM
The code that follows is used to draw a maze on the screen, the
computer then has to try to solve the maze. The target is represented
by a @ and the creature that has to solve the maze by a
symbol I can’t type – 07H. You know the one I mean…Key U,D,L
or R to draw the maze, E to erase parts you don’t want, F to mark
the finish, and then S to start. The next instruction will be at
0CB0, only you have to write it.
0CB0 Your turn.....