RAW Z80 Assembler
-----------------

A simple Z80 assembler.  The original was written by Roland A Wadilove for
the Amstrad CPC computer and was published in an Amstrad computing
magazine in the late 1980s.  (When I find the full references, I'll put
them in.)

Using the assembler is fairly easy.  On running, you are prompted for a
source filename and a destination filename.  The assembler makes two
passes through the source file and outputs the object code to the
destination file.

The source code can be either a text file or a BASIC program.  The code
layout is the same as for using the BASIC in-line assembler.  Labels are
declared within the assembly code by prefixing with a '.', and outside the
assembler by using name=value.  The origin of the code is set using
P%=value outside the assembly.  The assembler will manage to assemble from
most BASIC source programs, most warnings generated by the non-assembly
code can be safely ignored.

Restrictions
------------
Not very fast...  Cannot define labels as strings.

Autorunning
-----------
A BASIC program can be made to run the assembler, so CHAINing the BASIC
program causes it to be assembled.  Use a structure at the start of the
program along the lines of the following:

IF?&FFF7=&6C:A$=$&600
IFPAGE>&8000:SYS"GetEnv"TO A$:A$=MID$(A$,1+INSTR(A$," ",1+INSTR(A$," ")))
asm$="^.AsmZ80_402"
name$="outfile"
IF?&FFF7<>&C3:OS."Key0 "+A$+"|M"+name$+"|M":OS."FX138,0,192":CH.asm$

Change the value of asm$ to be the filename of the assembler program and
name$ to be the output name to save the object code by.  Then, when the
program is CHAINed, it finds it's own filename, and if not running on a
Z80, passes it to the assembler program.  With a properly written source
program, if it is running on a Z80, it will continue and assemble using
the in-line assembler. See the example programs in the Samples directory.

History
-------
15/01/1992 v4.02 Minor tweeks: sets load&exec addresses after closing
		  file.  Allows more labels if sufficient memory.
05/03/1990 v4.01 Case insensitive - forces everything to upper case.  Will
		  assemble from Text file as well as BASIC.
01/03/1990 v4.00 Reads data from a file rather than within the program.
28/05/1989 v3.30 Reads data from program directly, allowing in-line
		  assembly style coding between [ and ]. Multi-statement
		  lines allowed.
20/05/1989 v3.00 Initial version translated from R.A.Wadilove's version
		  for the Amstrad.  Assembly statements appended to program
		  as DATA statements.