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26 Added signed and unsigned multiply opcodes to the assembler.

An opcode was added for a 'negate' instruction. This is a derived instruction
that turns into two instructions. Neg RX becomes an XOR -1,Rx followed by an
Add 1,Rx command. (Move 1+Rx,Rx would've stalled the bus by one cycle.)

Instructions now keep track of the source linenumber (but not yet filename)
where they were issued. That way, upon an error in linking at the end, the
instruction can be referenced by the proper line number. (Filenames are still
not implemented, hence include files may reference the line number of the
include file with no proper indication of that ... yet).

The OBJFILE intrface now supports a clos() function. This allows the
assembler to close and delete the object file for those cases where the
preprocessor encounters an error.

The master test file, sw/test.S, was adjuted as follows: many of the tests
within it can be separated by #ifdef lines. Hence, if you only wish to test
whether or not CARRY works, undefine all of the other ifdefs but leave the
CARRY_TEST defined. (PUSH_TEST, a test of the PUSH(RX,SP) macro, still doesn't
work because the assembler still doesn't implement macros. This is still a
coming feature.)

The master test file now has tests for the break function, as well as for the
new trap CC bit and the new multiply signed and unsigned instructions in the

Many error conditions were added to the assembler preprocessor. Now, if an
EOF is encountered in anything but the INITIAL state (not within a macro),
an error will be created. Likewise, any unrecognized preprocessor directive
will create an error.

The lexical analyzer now supports character values, such as 'a' or '\n' using
a C-type syntax. (Tri-graphs are not supported.) It also supports such
extended syntax as '$GPG'. (Hmm ... wonder why I needed that?)

The lexical analyzer now recognizes and properly supports #line preprocessor
output statements. Theselines are then used to track what source line errors
occurr at.

Operand precedence has been adjusted, so the assembler should be able to
properly handle things like 5+3*8 and get the same number answer as 3*8+5.
(This has been implemented, although not thoroughly tested.)

Upon completion of any preprocessing file, the assembler now checks the status
of the preprocessor as returned by its exit code. Anything other than a zero
status will cause the assembler to delete the resulting object code file it is
building and exit with an error.

The assembler also supports the '-d' command line flag to turn on debugging in
the yacc processor (setting yydebug). It'll produce a lot of debugging output,
but it just might help to figure out what 'syntax error' is actually taking
dgisselq 2599d 00h /zipcpu/trunk/sw/
20 Added a quick README to the debugger directory. dgisselq 2605d 00h /zipcpu/trunk/sw/
19 Here's the outlines of a debugger. dgisselq 2605d 00h /zipcpu/trunk/sw/
17 The ZOPCODES function zipi_to_string (ZIP CPU instruction to string, part of
the machine code dump) was adjusted to have closer to a fixed width output.
It no longer uses tab characters, which can have an unreliable effect.
dgisselq 2605d 00h /zipcpu/trunk/sw/
16 The assembler now supports:
1. Multiple data elements on a line. These are lines like:
WORD 5,8,4,1
which place the words 5, 8, 4, and 1 directly into the object code to be
referenced as data. Prior to this release, these lines would assemble
properly but only place '5' as a data element into the object code.

2. The '-E' preprocessor only directive is now supported to produce output
from the preprocessor and see what is (or is not) happening there.

3. The preprocessor now validly places "#line" comments into the file, which
the assembler picks up and uses in it's error codes. These help identify
where errors took place.

4. Zasm now looks for the preprocessor (zpp) in the same directory zasm was
run from, using the same directory prefix as zasm, whenever zasm is given such
a directory prefix.

And ... perhaps other things I've forgotten about.
dgisselq 2606d 07h /zipcpu/trunk/sw/
14 Removing zasm.cpp--the old assembler that never worked well. dgisselq 2608d 13h /zipcpu/trunk/sw/
13 Finally! The beginnings of the new assembler. It's not really polished yet,
and it is quite clunky, but it works!! (Lots of bugs and features left to
fix/implement: #include, #define macro(), #line tracking through the
preprocessor, a means of finding include files (and the preprocessor!) and
more. But, as a beginning, the basics are functinoal.
dgisselq 2608d 13h /zipcpu/trunk/sw/
12 Bunch of changes while trying to get a hello world program:
1. Right shifts by 32 or more now result in zero, or all of the top bit in the
case of ASRs.
2. zdump now properly includes addresses with dumped lines.
3. zparser now properly handles immediate values via the .DAT instruction.
dgisselq 2623d 05h /zipcpu/trunk/sw/
9 This checkin is the result of a watchdog timer test, and everything it took
to get the watchdog timer working. The timer function was simplified,
although it now uses a touch more resources--being able to count down 31
bits instead of 30. The parser was modified, since it couldn't handle
storing to register plus offsets like it was supposed to be able to. The
testbench, zippy_tb, was modified to accept an assembled machine code file
such as I might place on a board to test it.

Lots of work to get it working.

Looking at the files below, it looks like I'll need a second check in to check
in the watchdog timer test itself.
dgisselq 2624d 03h /zipcpu/trunk/sw/
8 Fixed the rotate left instruction to work in the zasm parser, and to be
properly referenced in the simulator. The instruction set documentation was
also adjusted to reflect what the CPU actually does.
dgisselq 2624d 09h /zipcpu/trunk/sw/
2 An initial load. No promises of what works or not, but this is where the
project is at.
dgisselq 2625d 03h /zipcpu/trunk/sw/

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