Zero2 Control Program

To Back-up
----------
Before use it is advisable to make a back-up copy of the cartridge.
	Reset the QL
	Press F2
	Put the master cartridge in mdv2_
	Put a blank cartridge in mdv1_
	Enter LRUN mdv2_clone

This will format the cartridge in mdv1_ and copy over all the files from 
the master cartridge.

To Use
------
	Reset the QL
	Put the cartridge in mdv1_
	Press F2

The boot program  will  load  automatically and will then load and run 
the main program Robot. Robot will then look in files Zmem and Zmem_names 
to see if any routines were saved from the last session, and if so  it will 
load them into its memory. It then  prompts  for a speed-factor and gives 
an option to set the pen position to 'up'. If this option is not taken the 
it presumes the pen is already in the 'up' position.

The speed-factor and pen position initialisation can be done at any time 
by entering zinit which alsi initialises the serial channel, or just the 
pen position can be altered by entering peninit.

Entering help will display a series of 'Help' screens listing all the 
commands available to  the  user that the program understands. However 
since the user is operating directly in SuperBasic (see  next section) 
any legal SuperBasic command will be executed, even 'list'.

At the end of a sesssion enter quit and this will update and close the 
files Zmem and Zmem-names. Failure to use quit will almost certainly 
leave Zmem and Zmem-names in a poor state as the QL file buffers are only 
flushed when the files are closed. Should it happen the program will 
probably error in the next session when any long-term memory routine is 
called (by mexec). 
Entering LRUN mdv1_Initmem will restore Zmem and Zmem-names to their empty 
state.

Cartridge FIles

  Boot		loading program for Robot			Basic
  Robot		robot control program				Basic
  Zmem		holds all long-term memory routines		Data
  Zmem-names 	holds routine names and lenghts			Data
  Initmem	initialises Zmem and Zmem-names to empty	Basic
  Clone		cartridge bac-up program			Basic

Program Operation
-----------------
Most of the program consists of SuperBasic procedures which are invoked 
directly by the user at the keyboard and since the early QLs (pre JS) 
had no error trapping facilities available from SuperBasic the program 
uses two ways to protect itself.

a) 
For thos procedures which are learnable robot commands and are also User 
invoked with a parameter eg. 'FD n' etc. failure to append any parameter 
will lead to a program error. This can be overcome by then entering oops 
which prompts for the missing data and executes a SuperBasic RETRY.

b) 
Other procedures are invoked by name only and they then request any data 
they need.