diff --git a/README.md b/README.md
index ecd5e43..c2614b2 100644
--- a/README.md
+++ b/README.md
@@ -15,8 +15,8 @@ Usage: ./obj2hex.pl [options...] arguments
        --bytes=N               bytes per block on output
        --nocrc                 inhibit output of CRC-16 in hex format
        --logfile=LOGFILE       logging message file
-       --objfile=OBJFILE       macro11 object .obj file
        --outfile=OUTFILE       output .hex/.txt/.bin file
+       OBJFILE...              macro11 object .obj file(s)
 Aborted due to command line errors.
 ```
 
@@ -28,8 +28,8 @@ NAME
 
 SYNOPSIS
     obj2hex.pl [--help] [--debug] [--verbose] [--boot] [--console] [--binary]
-    [--ascii] [--bytes=N] [--nocrc] [--logfile=LOGFILE] --objfile=OBJFILE
-    --outfile=BINFILE
+    [--ascii] [--bytes=N] [--nocrc] [--logfile=LOGFILE] --outfile=BINFILE
+    OBJFILE...
 
 DESCRIPTION
     Converts a Macro-11 object file to various output formats, including M9312
@@ -86,12 +86,12 @@ OPTIONS
     --logfile=FILENAME
         Generate debug output into this file.
 
-    --objfile=FILENAME
-        Input objject file in .obj format.
-
     --outfile=FILENAME
         Output binary file in format selected by user option.
 
+    OBJFILE...
+        Input object file(s) in .obj format.
+
 ERRORS
     The following diagnostic error messages can be produced on STDERR. The
     meaning should be fairly self explanatory.
@@ -124,9 +124,9 @@ EXAMPLES
 
       obj2hex.pl --help
 
-      obj2hex.pl --verbose --boot --in 23-751A9.obj --out 23-751A9.hex
+      obj2hex.pl --verbose --boot --out 23-751A9.hex 23-751A9.obj
 
-      obj2hex.pl --verbose --binary --in memtest.obj --out memtest.bin
+      obj2hex.pl --verbose --binary --out memtest.bin memtest.obj
 
 AUTHOR
     Don North - donorth <ak6dn _at_ mindspring _dot_ com>
@@ -140,4 +140,6 @@ HISTORY
       2016-01-20 v1.3 donorth - Initial support for linking multiple PSECTs.
       2016-01-22 v1.4 donorth - Added objfile/outfile/logfile switches vs stdio.
       2016-01-28 v1.5 donorth - Added RLD processing, especially complex.
+      2017-04-01 v2.0 donorth - Started to add capability to process multiple
+                                input object files ... still a work in progress.
 ```
diff --git a/obj2hex.pl b/obj2hex.pl
index 7ced521..b27a3fc 100644
--- a/obj2hex.pl
+++ b/obj2hex.pl
@@ -1,1059 +1,1075 @@
-#!/usr/bin/perl -w
-#!/usr/local/bin/perl -w
-
-# Copyright (c) 2005-2016 Don North
-# All rights reserved.
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions
-# are met:
-# 
-# o Redistributions of source code must retain the above copyright
-#   notice, this list of conditions and the following disclaimer.
-# 
-# o Redistributions in binary form must reproduce the above copyright
-#   notice, this list of conditions and the following disclaimer in the
-#   documentation and/or other materials provided with the distribution.
-# 
-# o Neither the name of the copyright holder nor the names of its
-#   contributors may be used to endorse or promote products derived from
-#   this software without specific prior written permission.
-# 
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-# HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
-# TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
-# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
-# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
-# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-require 5.008;
-
-=head1 NAME
-
-obj2hex.pl - Convert a Macro-11 program image to PROM/load format
-
-=head1 SYNOPSIS
-
-obj2hex.pl
-S<[--help]>
-S<[--debug]>
-S<[--verbose]>
-S<[--boot]>
-S<[--console]>
-S<[--binary]>
-S<[--ascii]>
-S<[--bytes=N]>
-S<[--nocrc]>
-S<[--logfile=LOGFILE]>
-S<--objfile=OBJFILE>
-S<--outfile=BINFILE>
-
-=head1 DESCRIPTION
-
-Converts a Macro-11 object file to various output formats,
-including M9312 boot and console PROM, straight binary records,
-ASCII format for M9312 console load commands, and loadable absolute
-binary program images (.BIN) files.
-
-Currently the program is limited to a single object input file that
-can be output in the selected format. Multiple .psect/.asect ops are
-supported, as well as all local (non-global) relocation directory
-entries. Multiple object files are (not yet) supported.
-
-=head1 OPTIONS
-
-The following options are available:
-
-=over
-
-=item B<--help>
-
-Output this manpage and exit the program.
-
-=item B<--debug>
-
-Enable debug mode; print input file records as parsed.
-
-=item B<--verbose>
-
-Verbose status; output status messages during processing.
-
-=item B<--boot>
-
-Generate a hex PROM file image suitable for programming into
-an M9312 boot prom (512x4 geometry, only low half used).
-
-=item B<--console>
-
-Generate a hex PROM file image suitable for programming into
-an M9312 console/diagnostic prom (1024x4 geometry).
-
-=item B<--binary>
-
-Generate binary format load records of the program image (paper
-tape format) for loading into SIMH or compatible simulators.
-These files can also be copied onto XXDP filesystems to generate
-runnable program images (used to write custom diaqnostics).
-
-=item B<--ascii>
-
-Generate a a sequence of 'L addr' / 'D data' commands for downloading
-a program via a terminal emulator thru the M9312 user command interface.
-Suitable only for really small test programs.
-
-Exactly ONE of B<--boot>, B<--console>, B<--binary>, or B<--ascii>
-must be specified.
-
-=item B<--bytes=N>
-
-For hex format output files, output N bytes per line (default 16).
-
-=item B<--nocrc>
-
-For hex format output files, don't automatically stuff the computed
-CRC-16 as the last word in the ROM.
-
-=item B<--logfile=FILENAME>
-
-Generate debug output into this file.
-
-=item B<--objfile=FILENAME>
-
-Input objject file in .obj format.
-
-=item B<--outfile=FILENAME>
-
-Output binary file in format selected by user option.
-
-=back
-
-=head1 ERRORS
-
-The following diagnostic error messages can be produced on STDERR.
-The meaning should be fairly self explanatory.
-
-C<Aborted due to command line errors> -- bad option or missing file(s)
-
-C<Can't open input file '$file'> -- bad filename or unreadable file
-
-C<Error: Improper object file format (1)> -- valid record must start with 0x01
-
-C<Error: Improper object file format (2)> -- second byte must be 0x00
-
-C<Error: Improper object file format (3)> -- third byte is low byte of record length
-
-C<Error: Improper object file format (4)> -- fourth byte is high byte of record length
-
-C<Error: Improper object file format (5)> -- bytes five thru end-1 are data bytes
-
-C<Error: Improper object file format (6)> -- last byte is checksum
-
-C<Error: Bad checksum exp=0x%02X rcv=0x%02X> -- compare rcv'ed checksum vs exp'ed checksum
-
-=head1 EXAMPLES
-
-Some examples of common usage:
-
-  obj2hex.pl --help
-
-  obj2hex.pl --verbose --boot --in 23-751A9.obj --out 23-751A9.hex
-
-  obj2hex.pl --verbose --binary --in memtest.obj --out memtest.bin
-
-=head1 AUTHOR
-
-Don North - donorth <ak6dn _at_ mindspring _dot_ com>
-
-=head1 HISTORY
-
-Modification history:
-
-  2005-05-05 v1.0 donorth - Initial version.
-  2016-01-15 v1.1 donorth - Added RLD(IR) processing, moved sub's to end.
-  2016-01-18 v1.2 donorth - Added GSD processing, improved debug output.
-  2016-01-20 v1.3 donorth - Initial support for linking multiple PSECTs.
-  2016-01-22 v1.4 donorth - Added objfile/outfile/logfile switches vs stdio.
-  2016-01-28 v1.5 donorth - Added RLD processing, especially complex.
-
-=cut
-
-# options
-use strict;
-	
-# external standard modules
-use Getopt::Long;
-use Pod::Text;
-use FindBin;
-use FileHandle;
-
-# external local modules search path
-BEGIN { unshift(@INC, $FindBin::Bin);
-        unshift(@INC, $ENV{PERL5LIB}) if defined($ENV{PERL5LIB}); # cygwin bugfix
-        unshift(@INC, '.'); }
-
-# external local modules
-
-# generic defaults
-my $VERSION = 'v1.5'; # version of code
-my $HELP = 0; # set to 1 for man page output
-my $DEBUG = 0; # set to 1 for debug messages
-my $VERBOSE = 0; # set to 1 for verbose messages
-
-# specific defaults
-my $crctype = 'CRC-16'; # type of crc calc to do
-my $memsize; # number of instruction bytes allowed
-my $memfill; # memory fill pattern
-my %excaddr; # words to be skipped in rom crc calc
-my $rombase; # base address of rom image
-my $romsize; # number of rom addresses
-my $romfill; # rom fill pattern
-my $romtype = 'NONE'; # default rom type
-my $bytesper = -1; # bytes per block in output file
-my $nocrc = 0; # output CRC16 as last word unless set
-my $objfile = undef; # input filename
-my $outfile = undef; # output filename
-my $logfile = undef; # log filename
-
-# process command line arguments
-my $NOERROR = GetOptions( "help"        => \$HELP,
-			  "debug"       => \$DEBUG,
-			  "verbose"     => \$VERBOSE,
-			  "boot"        => sub { $romtype = 'BOOT'; },
-			  "console"     => sub { $romtype = 'DIAG'; },
-			  "binary"      => sub { $romtype = 'BINA'; },
-			  "ascii"       => sub { $romtype = 'ASC9'; },
-			  "bytes=i"     => \$bytesper,
-			  "nocrc"       => \$nocrc,
-			  "objfile=s"   => \$objfile,
-			  "outfile=s"   => \$outfile,
-			  "logfile=s"   => \$logfile,
-			  );
-
-# init
-$VERBOSE = 1 if $DEBUG; # debug implies verbose messages
-
-# output the documentation
-if ($HELP) {
-    # output a man page if we can
-    if (ref(Pod::Text->can('new')) eq 'CODE') {
-	# try the new way if appears to exist
-	my $parser = Pod::Text->new(sentence=>0, width=>78);
-	printf STDOUT "\n"; $parser->parse_from_file($0);
-    } else {
-	# else must use the old way
-	printf STDOUT "\n"; Pod::Text::pod2text(-78, $0);
-    };
-    exit(1);
-}
-
-# check for correct arguments present, print usage if errors
-unless ($NOERROR
-	&& scalar(@ARGV) == 0
-	&& defined($objfile)
-	&& defined($outfile)
-	&& $romtype ne 'NONE'
-    ) {
-    printf STDERR "obj2hex.pl %s by Don North (perl %g)\n", $VERSION, $];
-    print STDERR "Usage: $0 [options...] arguments\n";
-    print STDERR <<"EOF";
-       --help                  output manpage and exit
-       --debug                 enable debug mode
-       --verbose               verbose status reporting
-       --boot                  M9312 boot prom
-       --console               M9312 console/diagnostic prom
-       --binary                binary program load image
-       --ascii                 ascii m9312 program load image
-       --bytes=N               bytes per block on output
-       --nocrc                 inhibit output of CRC-16 in hex format
-       --logfile=LOGFILE       logging message file
-       --objfile=OBJFILE       macro11 object .obj file
-       --outfile=OUTFILE       output .hex/.txt/.bin file
-EOF
-    # exit if errors...
-    die "Aborted due to command line errors.\n";
-}
-
-# setup log file as a file, defaults to STDERR if not supplied
-my $LOG = defined($logfile) ? FileHandle->new("> ".$logfile) : FileHandle->new_from_fd(fileno(STDERR),"w");
-
-#----------------------------------------------------------------------------------------------------
-
-# subroutine prototypes
-
-sub trim ($);
-sub chksum (@);
-sub rad2asc (@);
-sub crc (%);
-sub read_rec ($);
-
-#----------------------------------------------------------------------------------------------------
-
-# fill in the parameters of the device
-
-if ($romtype eq 'BOOT') {
-
-    # M9312 512x4 boot prom
-    %excaddr = ( 024=>1, 025=>1 ); # bytes to be skipped in rom crc calc
-    $memsize = 128; # number of instruction bytes allowed
-    $memfill = 0x00; # memory fill pattern
-    $romsize = 512; # number of rom addresses (must be a power of two)
-    $romfill = 0x00; # rom fill pattern
-    $rombase = 0173000; # base address of rom
-
-} elsif ($romtype eq 'DIAG') {
-
-    # M9312 1024x4 diagnostic/console prom
-    %excaddr = ( ); # bytes to be skipped in rom crc calc
-    $memsize = 512; # number of instruction bytes allowed
-    $memfill = 0x00; # memory fill pattern
-    $romsize = 1024; # number of rom addresses (must be a power of two)
-    $romfill = 0x00; # rom fill pattern
-    $rombase = 0165000; # base address of rom
-
-} elsif ($romtype eq 'BINA' || $romtype eq 'ASC9') {
-
-    # program load image ... 56KB address space maximum
-    %excaddr = ( ); # bytes to be skipped in rom crc calc
-    $memsize = 7*8192; # number of instruction bytes allowed
-    $memfill = 0x00; # memory fill pattern
-    $romsize = 8*8192; # number of rom addresses (must be a power of two)
-    $romfill = 0x00; # image fill pattern
-    $rombase = 0; # base address of binary image
-
-} else {
-
-    # unknown ROM type code
-    die "ROM type '$romtype' is not supported!\n";
-
-}
-
-if ($VERBOSE) {
-    printf $LOG "ROM type is '%s'\n", $romtype;
-    printf $LOG "ROM space is %d. bytes\n", $memsize;
-    printf $LOG "ROM length is %d. addresses\n", $romsize;
-    printf $LOG "ROM base address is 0%06o\n", $rombase;
-}
-
-#----------------------------------------------------------------------------------------------------
-
-# read/process the input object file records
-
-# real pdp11 memory data words in boot prom
-my @mem = ((0) x $memsize);
-
-# min/max address limits in object file
-my ($adrmin,$adrmax) = ('','');
-
-# state variables in processing object records
-my $rommsk = ($romsize-1)>>1; # address bit mask
-my $adrmsk = 0xFFFF; # 16b addr mask
-my $datmsk = 0xFFFF; # 16b data mask
-my $memmsk = 0xFF; # 8b memory data mask
-    
-# open the input .obj file, die if error
-my $OBJ = FileHandle->new("< ".$objfile);
-die "Error: can't open input object file '$objfile'\n" unless defined $OBJ;
-
-# databases
-my %gblsym = ();
-my %psect = ();
-my @psect = ();
-my %program = ();
-my $psectname = '. ABS.';
-my $psectaddr = 0;
-my $psectnumb = -1;
-my $textaddr = 0;
-
-# program defaults
-$program{START}{VALUE} = 1;
-$program{START}{PSECT} = '. ABS.';
-
-# now parse all the records
-while (my @rec = &read_rec($OBJ)) {
-
-    # type is first byte of record
-    my $key = $rec[0];
-
-    if ($key == 001) { # GSD
-
-	# iterate over GSD subrecords
-	for (my $i = 2; $i < @rec; ) {
-	    # GSD records are fixed 8B length all in the same format
-	    my $nam = &rad2asc(($rec[$i+1]<<8)|($rec[$i+0]<<0), ($rec[$i+3]<<8)|($rec[$i+2]<<0));
-	    my $flg = $rec[$i+4];
-	    my $ent = $rec[$i+5];
-	    my $val = ($rec[$i+7]<<8)|($rec[$i+6]<<0);
-	    my @ent = ('MODULE','CSECT','INTSYM','XFRADR','GBLSYM','PSECT','IDENT','VSECT');
-	    if ($ent == 3) {
-		# XFRADR
-		$program{START}{PSECT} = $nam;
-		$program{START}{VALUE} = $val;
-	    } elsif ($ent == 4) {
-		# GBLSYM flags
-		$gblsym{$nam}{FLG}{$flg&(1<<0) ? "WEA" : "STR"}++;
-		$gblsym{$nam}{FLG}{$flg&(1<<3) ? "DEF" : "REF"}++;
-		$gblsym{$nam}{FLG}{$flg&(1<<5) ? "REL" : "ABS"}++;
-		$gblsym{$nam}{PSECT} = $psectname;
-		$gblsym{$nam}{VALUE} = $val;
-	    } elsif ($ent == 5) {
-		# PSECT flags
-		$psect[++$psectnumb] = $nam;
-		$psect{$nam}{NUMBER} = $psectnumb;
-		$psect{$nam}{FLG}{$flg&(1<<0) ? "GBL" : $flg&(1<<6) ? "GBL" : "LCL"}++;
-		$psect{$nam}{FLG}{$flg&(1<<2) ? "OVR" : "CAT"}++;
-		$psect{$nam}{FLG}{$flg&(1<<4) ? "R/O" : "R/W"}++;
-		$psect{$nam}{FLG}{$flg&(1<<5) ? "REL" : "ABS"}++;
-		$psect{$nam}{FLG}{$flg&(1<<7) ? "D"   : "I/D"}++;
-		if ($psect{$nam}{FLG}{CAT}) {
-		    $psect{$nam}{LENGTH} = $val;
-		    $psect{$nam}{START} = $psectaddr;
-		    $psectname = $nam;
-		    $psectaddr += $val;
-		} elsif ($psect{$nam}{FLG}{ABS}) {
-		    $psect{$nam}{LENGTH} = $val;
-		    $psect{$nam}{START} = 0;
-		    $psectname = $nam;
-		}
-	    }
-	    if ($DEBUG) {
-		printf $LOG "..GSD: type='%-6s'(%03o) name='%s' value=%06o", $ent[$ent], $ent, $nam, $val;
-		printf $LOG " flags=%s", join(",", sort(keys(%{$gblsym{$nam}{FLG}}))) if $ent == 4;
-		printf $LOG " flags=%s", join(",", sort(keys(%{$psect{$nam}{FLG}}))) if $ent == 5;
-		printf $LOG "\n";
-	    }
-	    $i += 8;
-	}
-
-    } elsif ($key == 002) { # ENDGSD
-
-	# just say we saw it
-	printf $LOG "..ENDGSD\n" if $DEBUG;
-
-	$program{END}{ADDRESS} = 0;
-	foreach my $nam (sort(keys(%psect))) {
-	    my $start = $psect{$nam}{START};
-	    my $length = $psect{$nam}{LENGTH};
-	    my $end = $length ? $start + $length - 1 : $start;
-	    $program{END}{ADDRESS} = $end if $end > $program{END}{ADDRESS};
-	    printf $LOG "..PSECT[%d](%s) START=%06o END=%06o LENGTH=%06o\n",
-	                $psect{$nam}{NUMBER}, $nam, $start, $end, $length if $length && $DEBUG;
-	}
-	$program{START}{ADDRESS} = $program{START}{VALUE} + $psect{$program{START}{PSECT}}{START};
-	printf $LOG "..PROG(ADDRESS) START=%06o END=%06o\n",
-	            $program{START}{ADDRESS}, $program{END}{ADDRESS} if $DEBUG;
-
-    } elsif ($key == 003) { # TXT
-
-	# process text record
-	my $off = ($rec[3]<<8)|($rec[2]<<0);
-	my $len = @rec-4;
-	my $base = $psect{$psectname}{START};
-	my $adr = ($base + $off) & $adrmsk;
-	foreach my $i (1..$len) { $mem[$adr+$i-1] = $rec[4+$i-1]; }
-	if ($DEBUG) {
-	    printf $LOG "..TXT OFFSET=%06o LENGTH=%o BASE=%06o PSECTNAME='%s'\n", $off, $len, $base, $psectname;
-	    for (my $i = 0; $i < $len; $i += 2) {
-		printf $LOG "      %06o: ", ($adr+$i)&~1 if $i%8 == 0;
-		printf $LOG " %03o...", $mem[$adr+$i++] if ($adr+$i)&1;
-		printf $LOG " %06o", ($mem[$adr+$i+1]<<8)|($mem[$adr+$i+0]<<0) if $i < $len-1;
-		printf $LOG " ...%03o", $mem[$adr+$i] if $i == $len-1;
-		printf $LOG "\n" if $i%8 >= 6 && $i < $len-2;
-	    }
-	    printf $LOG "\n";
-	}
-	$adrmin = $adr        if $adrmin eq '' || $adr        < $adrmin;
-	$adrmax = $adr+$len-1 if $adrmax eq '' || $adr+$len-1 > $adrmax;
-	$textaddr = $adr;
-
-    } elsif ($key == 004) { # RLD
-
-	# iterate over RLD subrecords
-	for (my $i = 2; $i < @rec; ) {
-	    # first byte is entry type and flags
-	    my $ent = $rec[$i+0] & 0x7F; # entry type
-	    my $flg = $rec[$i+0] & 0x80; # modification flag (0=word, 1=byte)
-	    # process an entry
-	    if ($ent == 001) {
-		# internal relocation ... OK
-		my $dis = $rec[$i+1];
-		my $con = ($rec[$i+3]<<8)|($rec[$i+2]<<0);
-		# process
-		my $adr = $adrmsk & ($textaddr + $dis - 4);
-		my $val = $datmsk & ($psect{$psectname}{START} + $con);
-		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
-		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
-		printf $LOG "..RLD(IR):   adr=%06o val=%06o ; dis=%06o con=%06o\n",
-		            $adr, $val, $dis, $con if $DEBUG;
-		$i += 4;
-	    } elsif ($ent == 002) {
-		# global relocation ... TBD <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
-		my $dis = $rec[$i+1];
-		my $nam = &rad2asc(($rec[$i+3]<<8)|($rec[$i+2]<<0), ($rec[$i+5]<<8)|($rec[$i+4]<<0));
-		# process
-		printf $LOG "..RLD(GR):   dis=%06o nam='%s'\n",
-		            $dis, $nam if $DEBUG;
-		$i += 6;
-	    } elsif ($ent == 003) {
-		# internal displaced ... OK
-		my $dis = $rec[$i+1];
-		my $con = ($rec[$i+3]<<8)|($rec[$i+2]<<0);
-		# process
-		my $adr = $adrmsk & ($textaddr + $dis - 4);
-		my $val = $datmsk & ($con - ($adr+2));
-		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
-		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
-		printf $LOG "..RLD(ID):   adr=%06o val=%06o ; dis=%06o con=%06o\n",
-		            $adr, $val, $dis, $con if $DEBUG;
-		$i += 4;
-	    } elsif ($ent == 004) {
-		# global displaced relocation ... TBD <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
-		my $dis = $rec[$i+1];
-		my $nam = &rad2asc(($rec[$i+3]<<8)|($rec[$i+2]<<0), ($rec[$i+5]<<8)|($rec[$i+4]<<0));
-		# process
-		printf $LOG "..RLD(GDR):  dis=%06o nam='%s'\n",
-		            $dis, $nam if $DEBUG;
-		$i += 6;
-	    } elsif ($ent == 005) {
-		# global additive relocation ... TBD <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
-		my $dis = $rec[$i+1];
-		my $nam = &rad2asc(($rec[$i+3]<<8)|($rec[$i+2]<<0), ($rec[$i+5]<<8)|($rec[$i+4]<<0));
-		my $con = ($rec[$i+7]<<8)|($rec[$i+6]<<0);
-		# process
-		printf $LOG "..RLD(GAR):  dis=%06o con=%06o nam='%s'\n",
-		            $dis, $con, $nam if $DEBUG;
-		$i += 8;
-	    } elsif ($ent == 006) {
-		# global additive displaced relocation ... TBD <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
-		my $dis = $rec[$i+1];
-		my $nam = &rad2asc(($rec[$i+3]<<8)|($rec[$i+2]<<0), ($rec[$i+5]<<8)|($rec[$i+4]<<0));
-		my $con = ($rec[$i+7]<<8)|($rec[$i+6]<<0);
-		# process
-		printf $LOG "..RLD(GADR): dis=%06o con=%06o nam='%s'\n",
-		            $dis, $con, $nam if $DEBUG;
-		$i += 8;
-	    } elsif ($ent == 007) {
-		# location counter definition ... OK
-		my $dis = $rec[$i+1];
-		my $nam = &rad2asc(($rec[$i+3]<<8)|($rec[$i+2]<<0), ($rec[$i+5]<<8)|($rec[$i+4]<<0));
-		my $con = ($rec[$i+7]<<8)|($rec[$i+6]<<0);
-		# process
-		$psectname = $nam;
-		$textaddr = $datmsk & ($con);
-		printf $LOG "..RLD(LCD):  adr=%06o            ; dis=%06o con=%06o nam='%s'\n",
-		            $textaddr, $dis, $con, $nam if $DEBUG;
-		$i += 8;
-	    } elsif ($ent == 010) {
-		# location counter modification ... OK
-		my $dis = $rec[$i+1];
-		my $con = ($rec[$i+3]<<8)|($rec[$i+2]<<0);
-		# process
-		$textaddr = $datmsk & ($con);
-		printf $LOG "..RLD(LCM):  adr=%06o            ; dis=%06o con=%06o\n",
-		            $textaddr, $dis, $con if $DEBUG;
-		$i += 4;
-	    } elsif ($ent == 011) {
-		# program limits ... OK, mostly
-		my $dis = $rec[$i+1];
-		# process
-		my $adr = $adrmsk & ($textaddr + $dis - 4);
-		my $val = $datmsk & ( 01000 ); # make this up, no easy way to compute it
-		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
-		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
-		printf $LOG "..RLD(LIM1): adr=%06o val=%06o ; dis=%06o\n",
-		            $adr, $val, $dis if $DEBUG;
-		$dis += 2;
-		$adr += 2;
-		$val = $datmsk & ($program{END}{ADDRESS});
-		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
-		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
-		printf $LOG "..RLD(LIM2): adr=%06o val=%06o ; dis=%06o\n",
-		            $adr, $val, $dis if $DEBUG;
-		$i += 2;
-	    } elsif ($ent == 012) {
-		# psect relocation ... OK
-		my $dis = $rec[$i+1];
-		my $nam = &rad2asc(($rec[$i+3]<<8)|($rec[$i+2]<<0), ($rec[$i+5]<<8)|($rec[$i+4]<<0));
-		# process
-		my $adr = $adrmsk & ($textaddr + $dis - 4);
-		my $val = $datmsk & ($psect{$nam}{START});
-		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
-		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
-		printf $LOG "..RLD(PR):   adr=%06o val=%06o ; dis=%06o nam='%s'\n",
-		            $adr, $val, $dis, $nam if $DEBUG;
-		$i += 6;
-	    } elsif ($ent == 014) {
-		# psect displaced relocation ... OK
-		my $dis = $rec[$i+1];
-		my $nam = &rad2asc(($rec[$i+3]<<8)|($rec[$i+2]<<0), ($rec[$i+5]<<8)|($rec[$i+4]<<0));
-		# process
-		my $adr = $adrmsk & ($textaddr + $dis - 4);
-		my $val = $datmsk & ($psect{$nam}{START} - ($adr+2));
-		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
-		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
-		printf $LOG "..RLD(PDR):  adr=%06o val=%06o ; dis=%06o nam='%s'\n",
-		            $adr, $val, $dis, $nam if $DEBUG;
-		$i += 6;
-	    } elsif ($ent == 015) {
-		# psect additive relocation ... OK
-		my $dis = $rec[$i+1];
-		my $nam = &rad2asc(($rec[$i+3]<<8)|($rec[$i+2]<<0), ($rec[$i+5]<<8)|($rec[$i+4]<<0));
-		my $con = ($rec[$i+7]<<8)|($rec[$i+6]<<0);
-		# process
-		my $adr = $adrmsk & ($textaddr + $dis - 4);
-		my $val = $datmsk & ($psect{$nam}{START} + $con);
-		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
-		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
-		printf $LOG "..RLD(PAR):  adr=%06o val=%06o ; dis=%06o con=%06o nam='%s'\n",
-		            $adr, $val, $dis, $con, $nam if $DEBUG;
-		$i += 8;
-	    } elsif ($ent == 016) {
-		# psect additive displaced relocation ... OK
-		my $dis = $rec[$i+1];
-		my $nam = &rad2asc(($rec[$i+3]<<8)|($rec[$i+2]<<0), ($rec[$i+5]<<8)|($rec[$i+4]<<0));
-		my $con = ($rec[$i+7]<<8)|($rec[$i+6]<<0);
-		# process
-		my $adr = $adrmsk & ($textaddr + $dis - 4);
-		my $val = $datmsk & ($psect{$nam}{START} + $con - ($adr+2));
-		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
-		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
-		printf $LOG "..RLD(PADR): adr=%06o val=%06o ; dis=%06o con=%06o nam='%s'\n",
-		            $adr, $val, $dis, $con, $nam if $DEBUG;
-		$i += 8;
-	    } elsif ($ent == 017) {
-		# complex relocation ... OK
-		my $dis = $rec[$i+1];
-		my $nam = '. ABS.';
-		my $con = 0;
-		# process
-		my $adr = $adrmsk & ($textaddr + $dis - 4);
-		my $loc = 0;
-		my $val = 0;
-		my $opc = "";
-		my @stk = ();
-		my $dun = 0;
-		for ($i += 2; !$dun; $i += 1) {
-		    if ($rec[$i] == 000) {
-			$opc = "NOP";
-		    } elsif ($rec[$i] == 001) {
-			my @arg = splice(@stk,-2,2);
-			push(@stk, $arg[0] + $arg[1]);
-			$opc = "ADD";
-		    } elsif ($rec[$i] == 002) {
-			my @arg = splice(@stk,-2,2);
-			push(@stk, $arg[0] - $arg[1]);
-			$opc = "SUB";
-		    } elsif ($rec[$i] == 003) {
-			my @arg = splice(@stk,-2,2);
-			push(@stk, $arg[0] * $arg[1]);
-			$opc = "MUL";
-		    } elsif ($rec[$i] == 004) {
-			my @arg = splice(@stk,-2,2);
-			push(@stk, $arg[1] == 0 ? 0 : int($arg[0] / $arg[1]));
-			$opc = "DIV";
-		    } elsif ($rec[$i] == 005) {
-			my @arg = splice(@stk,-2,2);
-			push(@stk, $arg[0] & $arg[1]);
-			$opc = "AND";
-		    } elsif ($rec[$i] == 006) {
-			my @arg = splice(@stk,-2,2);
-			push(@stk, $arg[0] | $arg[1]);
-			$opc = "IOR";
-		    } elsif ($rec[$i] == 007) {
-			my @arg = splice(@stk,-2,2);
-			push(@stk, $arg[0] ^ $arg[1]);
-			$opc = "XOR";
-		    } elsif ($rec[$i] == 010) {
-			my @arg = splice(@stk,-1,1);
-			push(@stk, -$arg[0]);
-			$opc = "NEG";
-		    } elsif ($rec[$i] == 011) {
-			my @arg = splice(@stk,-1,1);
-			push(@stk, ~$arg[0]);
-			$opc = "COM";
-		    } elsif ($rec[$i] == 012) {
-			my @arg = splice(@stk,-1,1);
-			$val = $arg[0];
-			$opc = "STO";
-			$dun = 1;
-		    } elsif ($rec[$i] == 013) {
-			############## may need tweaking ################
-			my @arg = splice(@stk,-1,1);
-			$val = $arg[0];
-			$opc = "STO+DIS";
-			$dun = 1;
-		    } elsif ($rec[$i] == 016) {
-			############## may need tweaking ################
-			$nam = &rad2asc(($rec[$i+2]<<8)|($rec[$i+1]<<0),
-					($rec[$i+4]<<8)|($rec[$i+3]<<0));
-			$con = $gblsym{$nam}{VALUE};
-			push(@stk, $con);
-			$opc = sprintf("GLB[%s]=(%o)", &trim($nam), $con);
-			$i += 4;
-		    } elsif ($rec[$i] == 017) {
-			$nam = $psect[$rec[$i+1]];
-			$con = ($rec[$i+3]<<8) | ($rec[$i+2]<<0);
-			$loc = $psect{$nam}{START} + $con;
-			push(@stk, $loc);
-			$opc = sprintf("FET[%s+%o]=(%o)", &trim($nam), $con, $loc);
-			$i += 3;
-		    } elsif ($rec[$i] == 020) {
-			$con = ($rec[$i+2]<<8) | ($rec[$i+1]<<0);
-			push(@stk, $con);
-			$opc = "CON";
-			$i += 2;
-		    }
-		    $stk[-1] = $datmsk & $stk[-1] if @stk;
-		    printf $LOG "....OPC=%-20s STK=(%s)\n", $opc, join(",",map(sprintf("%o",$_),@stk)) if $DEBUG;
-		}
-		printf $LOG "..RLD(CMPX): adr=%06o val=%06o ; dis=%06o\n", $adr, $val, $dis if $DEBUG;
-	    } else {
-		die sprintf("Error: Unknown RLD entry 0%o (%d)", $ent, $ent);
-	    }
-	}
-
-    } elsif ($key == 005) { # ISD
-
-	# ignore
-	printf $LOG "..ISD: ignored\n" if $DEBUG;
-
-    } elsif ($key == 006) { # ENDMOD
-
-	# just say we saw it
-	printf $LOG "..ENDMOD\n\n\n" if $DEBUG;
-
-    } elsif ($key == 007) { # LIBHDR
-
-	# ignore
-	printf $LOG "..LIBHDR: ignored\n" if $DEBUG;
-
-    } elsif ($key == 010) { # LIBEND
-
-	# ignore
-	printf $LOG "..LIBEND: ignored\n" if $DEBUG;
-
-    } else { # unknown
-
-	# invalid record type in the object file
-	die sprintf("Error: unknown record type 0%o (%d)", $key, $key);
-
-    }
-
-}
-
-# done with object file
-$OBJ->close;
-
-#----------------------------------------------------------------------------------------------------
-
-# compute CRC if required, copy memory image to output buffer
-
-my @buf = ($romfill) x $romsize; # physical PROM data bytes, filled background pattern
-
-# only compute CRC on M9312 ROMs
-if ($romtype eq 'BOOT' || $romtype eq 'DIAG') {
-
-    # compute CRC-16 of the prom contents (except exception words) and store at last location
-    my $crctab = &crc(-name=>$crctype, -new=>1);
-    my $crc = &crc(-name=>$crctype, -init=>1);
-    for (my $adr = 0; $adr < $memsize-2; $adr += 1) {
-	next if exists($excaddr{$adr}); # skip these addresses
-	$mem[$rombase+$adr] = $memfill unless defined($mem[$rombase+$adr]);
-	$crc = &crc(-name=>$crctype, -table=>$crctab, -crc=>$crc, -byte=>$mem[$rombase+$adr]);
-    }
-    $crc = &crc(-name=>$crctype, -crc=>$crc, -last=>1);
-    unless ($nocrc) {
-	# output computed CRC-16 as last word in the ROM file
-	$mem[$rombase+$memsize-2] = ($crc>>0)&0xFF;
-	$mem[$rombase+$memsize-1] = ($crc>>8)&0xFF;
-    }
-    printf $LOG "ROM %s is %06o (0x%04X)\n", $crctype, ($crc) x 2 if $VERBOSE;
-
-    # process data words to actual PROM byte data
-    # put 4bit nibble in low 4b of each 8b data byte, zero the upper 4b
-    # only copy the above instruction portion over
-    for (my $idx = 0; $idx < $memsize<<1; $idx += 4) {
-	my $dat = ($mem[$rombase+($idx>>1)+1]<<8) | ($mem[$rombase+($idx>>1)+0]<<0);
-	$buf[$idx+0] = ($dat&0xE)|(($dat>>8)&0x1);       # bits   3   2   1   8
-	$buf[$idx+1] = ($dat>>4)&0xF;                    # bits   7   6   5   4
-	$buf[$idx+2] = ((($dat>>8)&0xE)|($dat&0x1))^0xC; # bits ~11 ~10   9   0
-	$buf[$idx+3] = (($dat>>12)&0xF)^0x1;             # bits  15  14  13 ~12
-    }
-
-} elsif ($romtype eq 'BINA' || $romtype eq 'ASC9') {
-
-    # only copy the above instruction portion over
-    for (my $adr = 0; $adr < $memsize; $adr += 1) {
-	$mem[$rombase+$adr] = $memfill unless defined($mem[$rombase+$adr]);
-	$buf[$adr] = $mem[$rombase+$adr];
-    }
-
-}
-
-if ($VERBOSE) {
-
-    # print checksum of entire device
-    my $chksum = 0; map($chksum += $_, @buf);
-    printf $LOG "ROM checksum is %06o (0x%04X)\n", $chksum, $chksum;
-
-}
-
-#----------------------------------------------------------------------------------------------------
-
-# output the linked/processed binary file image in the desired format
-
-my $OUT = FileHandle->new("> ".$outfile);
-die "Error: can't open output file '$outfile'\n" unless defined $OUT;
-
-if ($romtype eq 'BOOT' || $romtype eq 'DIAG') {
-    
-    # output the entire PROM buffer as an intel hex file
-
-    $bytesper = 16 if $bytesper <= 0;
-
-    for (my $idx = 0; $idx < $romsize; $idx += $bytesper) {
-	my $cnt = $idx+$bytesper <= $romsize ? $bytesper : $romsize-$idx; # N bytes or whatever is left
-	my @dat = @buf[$idx..($idx+$cnt-1)]; # get the data
-	my $dat = join('', map(sprintf("%02X",$_),@dat)); # map to ascii text
-	printf $OUT ":%02X%04X%02X%s%02X\n", $cnt, $idx, 0x00, $dat, &chksum($cnt, $idx>>0, $idx>>8, 0x00, @dat);
-    }
-
-    printf $OUT ":%02X%04X%02X%s%02X\n", 0x00, 0x0000, 0x01, '', &chksum(0x0, 0x0000>>0, 0x0000>>8, 0x01);
-
-} elsif ($romtype eq 'BINA') {
-
-    # Loader format consists of blocks, optionally preceded, separated, and
-    # followed by zeroes.  Each block consists of:
-    #
-    #   001		---
-    #   000		 |
-    #   lo(length)	 |
-    #   hi(length)	 |
-    #   lo(address)	 > 'length' bytes
-    #   hi(address)	 |
-    #   databyte1	 |
-    #   :		 |
-    #   databyteN	---
-    #   checksum
-    #
-    # If the byte length is exactly six, the block is the last on the tape, and
-    # there is no checksum.  If the origin is not 000001, then the origin is
-    # the PC at which to start the program.
-
-    $bytesper = 128 if $bytesper <= 0;
-
-    my $start = $program{START}{ADDRESS};
-
-    sub m ($) { $_[0] & 0xFF; }
-
-    # output the entire PROM buffer as a binary loader file
-    for (my $idx = $adrmin; $idx < $adrmax+1; $idx += $bytesper) {
-	my $cnt = $idx+$bytesper <= $adrmax+1 ? $bytesper : $adrmax+1-$idx; # N bytes or whatever is left
-	my @dat = @buf[$idx..($idx+$cnt-1)]; # get the data
-	my $len = $cnt+6;
-	my @rec = (0x01, 0x00, &m($len>>0), &m($len>>8), &m($idx>>0), &m($idx>>8), @dat);
-	print $OUT pack("C*", @rec, &chksum(@rec));
-    }
-    my @end = (0x01, 0x00, 0x06, 0x00, &m($start>>0), &m($start>>8));
-    print $OUT pack("C*", @end, &chksum(@end));
-
-} elsif ($romtype eq 'ASC9') {
-
-    # ascii interface to M9312 console emulator
-
-    sub n ($) { $_[0] & 0xFF; }
-
-    # start program load here
-    printf $OUT "L %o\r\n", $adrmin;
-
-    # output the PROM buffer as an ascii load file
-    for (my $idx = $adrmin; $idx < $adrmax+1; $idx += 2) {
-	printf $OUT "D %06o\r\n", (&n($buf[$idx+1])<<8) | &n($buf[$idx+0]);
-    }
-
-    # start program exec here
-    printf $OUT "L %o\r\nS\r\n", $adrmin;
-
-}
-
-# all done
-$OUT->close;
-
-#----------------------------------------------------------------------------------------------------
-
-# really done
-$LOG->close;
-exit;
-
-#----------------------------------------------------------------------------------------------------
-
-# trim leading/trailing spaces on a string
-
-sub trim ($) {
-
-    my ($str) = @_;
-
-    $str =~ s/\s+$//;
-    $str =~ s/^\s+//;
-    
-    return $str;
-}
-
-#----------------------------------------------------------------------------------------------------
-
-# compute checksum (twos complement of the sum of bytes)
-
-sub chksum (@) {
-
-    my $sum = 0;
-
-    map($sum += $_, @_);
-
-    return (-$sum) & 0xFF;
-}
-
-#----------------------------------------------------------------------------------------------------
-
-# RAD50 to ASCII decode
-
-sub rad2asc (@) {
-
-    my @str = split(//, ' ABCDEFGHIJKLMNOPQRSTUVWXYZ$.%0123456789'); # RAD50 character subset
-
-    my $ascii = "";
-    foreach my $rad50 (@_) {
-	$ascii .= $str[int($rad50/1600)%40] . $str[int($rad50/40)%40] . $str[$rad50%40];
-    }
-
-    return $ascii;
-}
-
-#----------------------------------------------------------------------------------------------------
-
-# crc computation routine
-
-sub crc (%) {
-
-    # pass all args by name
-    my %args = @_;
-
-    # all the crcs we know how to compute
-    my %crcdat = ( 'CRC-16' => [ 0xA001,     2, 0x0000,     0x0000     ],
-		   'CRC-32' => [ 0xEDB88320, 4, 0xFFFFFFFF, 0xFFFFFFFF ] );
-
-    # run next byte thru crc computation, return updated crc
-    return $args{-table}[($args{-crc}^$args{-byte}) & 0xFF]^($args{-crc}>>8) if exists($args{-byte});
-
-    # return initial crc value
-    return $crcdat{$args{-name}}->[2] if exists($args{-init});
-
-    # return final crc value xored with xorout
-    return $args{-crc} ^ $crcdat{$args{-name}}->[3] if exists($args{-last});
-
-    # compute the crc lookup table, return a pointer to it
-    if (exists($args{-new})) {
-	my $crctab = [];
-	my $poly = $crcdat{$args{-name}}->[0];
-	foreach my $byte (0..255) {
-	    my $data = $byte;
-	    foreach (1..8) { $data = ($data>>1) ^ ($data&1 ? $poly : 0); }
-	    $$crctab[$byte] = $data;
-	}
-	return $crctab;
-    }
-}
-
-#----------------------------------------------------------------------------------------------------
-
-# read a record from the object file
-
-sub read_rec ($) {
-
-    my ($fh) = @_;
-
-    my ($buf, $cnt, $len, $err) = (0,0,0,0);
-    my @pre = ();
-    my @dat = ();
-    my @suf = ();
-
-    # Object file format consists of blocks, optionally preceded, separated, and
-    # followed by zeroes.  Each block consists of:
-    #
-    #   001		---
-    #   000		 |
-    #   lo(length)	 |
-    #   hi(length)	 > 'length' bytes
-    #   databyte1	 |
-    #   :		 |
-    #   databyteN	---
-    #   checksum
-    #
-
-    # skip over strings of 0x00; exit OK if hit EOF
-    do { return () unless $cnt = read($fh, $buf, 1); } while (ord($buf) == 0);
-
-    # valid record starts with (1)
-    $err = 1 unless $cnt == 1 && ord($buf) == 1;
-    push(@pre, ord($buf));
-
-    # second byte must be (0)
-    $cnt = read($fh, $buf, 1);
-    $err = 2 unless $cnt == 1 && ord($buf) == 0;
-    push(@pre, ord($buf));
-
-    # third byte is low byte of record length
-    $cnt = read($fh, $buf, 1);
-    $err = 3 unless $cnt == 1;
-    $len = ord($buf);
-    push(@pre, ord($buf));
-
-    # fourth byte is high byte of record length
-    $cnt = read($fh, $buf, 1);
-    $err = 4 unless $cnt == 1;
-    $len += ord($buf)<<8;
-    push(@pre, ord($buf));
-
-    # bytes five thru end-1 are data bytes
-    $cnt = read($fh, $buf, $len-4);
-    $err = 5 unless $cnt == $len-4 && $len >= 4;
-    @dat = unpack("C*", $buf);
-
-    # last byte is checksum
-    $cnt = read($fh, $buf, 1);
-    $err = 6 unless $cnt == 1;
-    my $rcv = ord($buf);
-    push(@suf, ord($buf));
-
-    # output the record if debugging
-    if ($DEBUG) {
-	my $fmt = "%03o";
-	my $n = 16;
-	my $pre = sprintf("RECORD: [%s] ",join(" ",map(sprintf($fmt,$_),@pre)));
-	printf $LOG "\n\n%s", $pre;
-	my $k = length($pre);
-	my @tmp = @dat;
-	while (@tmp > $n) {
-	    printf $LOG "%s\n%*s", join(" ",map(sprintf($fmt,$_),splice(@tmp,0,$n))), $k, '';
-	}
-	printf $LOG "%s", join(" ",map(sprintf($fmt,$_),@tmp)) if @tmp;
-	printf $LOG " [%s]\n\n", join(" ",map(sprintf($fmt,$_),@suf));
-    }
-
-    # check we have a well formatted record
-    die sprintf("Error: invalid object file record format (%d)", $err) if $err;
-
-    # compare rcv'ed checksum vs exp'ed checksum
-    my $exp = &chksum(0x01, $len>>0, $len>>8, @dat);
-    die sprintf("Error: Bad checksum exp=0x%02X rcv=0x%02X", $exp, $rcv) unless $exp == $rcv;
-
-    # all is well, return the record
-    return @dat;
-}
-
-#----------------------------------------------------------------------------------------------------
-
-# the end
+#!/usr/bin/perl -w
+#!/usr/local/bin/perl -w
+
+# Copyright (c) 2005-2016 Don North
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 
+# o Redistributions of source code must retain the above copyright
+#   notice, this list of conditions and the following disclaimer.
+# 
+# o Redistributions in binary form must reproduce the above copyright
+#   notice, this list of conditions and the following disclaimer in the
+#   documentation and/or other materials provided with the distribution.
+# 
+# o Neither the name of the copyright holder nor the names of its
+#   contributors may be used to endorse or promote products derived from
+#   this software without specific prior written permission.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+# TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+require 5.008;
+
+=head1 NAME
+
+obj2hex.pl - Convert a Macro-11 program image to PROM/load format
+
+=head1 SYNOPSIS
+
+obj2hex.pl
+S<[--help]>
+S<[--debug]>
+S<[--verbose]>
+S<[--boot]>
+S<[--console]>
+S<[--binary]>
+S<[--ascii]>
+S<[--bytes=N]>
+S<[--nocrc]>
+S<[--logfile=LOGFILE]>
+S<--outfile=BINFILE>
+S<OBJFILE>
+
+=head1 DESCRIPTION
+
+Converts a Macro-11 object files to various output formats,
+including M9312 boot and console PROM, straight binary records,
+ASCII format for M9312 console load commands, and loadable absolute
+binary program images (.BIN) files.
+
+Multiple .psect/.asect ops are supported, as well as all local
+(non-global) relocation directory entries.
+
+Multiple input object files are (not yet fully) supported - this
+part is work in progress. In particular definition and resolution
+of global symbols are not supported.
+
+=head1 OPTIONS
+
+The following options are available:
+
+=over
+
+=item B<--help>
+
+Output this manpage and exit the program.
+
+=item B<--debug>
+
+Enable debug mode; print input file records as parsed.
+
+=item B<--verbose>
+
+Verbose status; output status messages during processing.
+
+=item B<--boot>
+
+Generate a hex PROM file image suitable for programming into
+an M9312 boot prom (512x4 geometry, only low half used).
+
+=item B<--console>
+
+Generate a hex PROM file image suitable for programming into
+an M9312 console/diagnostic prom (1024x4 geometry).
+
+=item B<--binary>
+
+Generate binary format load records of the program image (paper
+tape format) for loading into SIMH or compatible simulators.
+These files can also be copied onto XXDP filesystems to generate
+runnable program images (used to write custom diaqnostics).
+
+=item B<--ascii>
+
+Generate a a sequence of 'L addr' / 'D data' commands for downloading
+a program via a terminal emulator thru the M9312 user command interface.
+Suitable only for really small test programs.
+
+Exactly ONE of B<--boot>, B<--console>, B<--binary>, or B<--ascii>
+must be specified.
+
+=item B<--bytes=N>
+
+For hex format output files, output N bytes per line (default 16).
+
+=item B<--nocrc>
+
+For hex format output files, don't automatically stuff the computed
+CRC-16 as the last word in the ROM.
+
+=item B<--logfile=FILENAME>
+
+Generate debug output into this file.
+
+=item B<--outfile=FILENAME>
+
+Output binary file in format selected by user option.
+
+=item B<OBJFILE...>
+
+Input object file(s) in .obj format.
+
+=back
+
+=head1 ERRORS
+
+The following diagnostic error messages can be produced on STDERR.
+The meaning should be fairly self explanatory.
+
+C<Aborted due to command line errors> -- bad option or missing file(s)
+
+C<Can't open input file '$file'> -- bad filename or unreadable file
+
+C<Error: Improper object file format (1)> -- valid record must start with 0x01
+
+C<Error: Improper object file format (2)> -- second byte must be 0x00
+
+C<Error: Improper object file format (3)> -- third byte is low byte of record length
+
+C<Error: Improper object file format (4)> -- fourth byte is high byte of record length
+
+C<Error: Improper object file format (5)> -- bytes five thru end-1 are data bytes
+
+C<Error: Improper object file format (6)> -- last byte is checksum
+
+C<Error: Bad checksum exp=0x%02X rcv=0x%02X> -- compare rcv'ed checksum vs exp'ed checksum
+
+=head1 EXAMPLES
+
+Some examples of common usage:
+
+  obj2hex.pl --help
+
+  obj2hex.pl --verbose --boot --out 23-751A9.hex 23-751A9.obj
+
+  obj2hex.pl --verbose --binary --out memtest.bin memtest.obj
+
+=head1 AUTHOR
+
+Don North - donorth <ak6dn _at_ mindspring _dot_ com>
+
+=head1 HISTORY
+
+Modification history:
+
+  2005-05-05 v1.0 donorth - Initial version.
+  2016-01-15 v1.1 donorth - Added RLD(IR) processing, moved sub's to end.
+  2016-01-18 v1.2 donorth - Added GSD processing, improved debug output.
+  2016-01-20 v1.3 donorth - Initial support for linking multiple PSECTs.
+  2016-01-22 v1.4 donorth - Added objfile/outfile/logfile switches vs stdio.
+  2016-01-28 v1.5 donorth - Added RLD processing, especially complex.
+  2017-04-01 v2.0 donorth - Started to add capability to process multiple
+                            input object files ... still a work in progress.
+
+=cut
+
+# options
+use strict;
+	
+# external standard modules
+use Getopt::Long;
+use Pod::Text;
+use FindBin;
+use FileHandle;
+
+# external local modules search path
+BEGIN { unshift(@INC, $FindBin::Bin);
+        unshift(@INC, $ENV{PERL5LIB}) if defined($ENV{PERL5LIB}); # cygwin bugfix
+        unshift(@INC, '.'); }
+
+# external local modules
+
+# generic defaults
+my $VERSION = 'v2.0'; # version of code
+my $HELP = 0; # set to 1 for man page output
+my $DEBUG = 0; # set to 1 for debug messages
+my $VERBOSE = 0; # set to 1 for verbose messages
+
+# specific defaults
+my $crctype = 'CRC-16'; # type of crc calc to do
+my $memsize; # number of instruction bytes allowed
+my $memfill; # memory fill pattern
+my %excaddr; # words to be skipped in rom crc calc
+my $rombase; # base address of rom image
+my $romsize; # number of rom addresses
+my $romfill; # rom fill pattern
+my $romtype = 'NONE'; # default rom type
+my $bytesper = -1; # bytes per block in output file
+my $nocrc = 0; # output CRC16 as last word unless set
+my $outfile = undef; # output filename
+my $logfile = undef; # log filename
+
+# process command line arguments
+my $NOERROR = GetOptions( "help"        => \$HELP,
+			  "debug"       => \$DEBUG,
+			  "verbose"     => \$VERBOSE,
+			  "boot"        => sub { $romtype = 'BOOT'; },
+			  "console"     => sub { $romtype = 'DIAG'; },
+			  "binary"      => sub { $romtype = 'BINA'; },
+			  "ascii"       => sub { $romtype = 'ASC9'; },
+			  "bytes=i"     => \$bytesper,
+			  "nocrc"       => \$nocrc,
+			  "outfile=s"   => \$outfile,
+			  "logfile=s"   => \$logfile,
+			  );
+
+# init
+$VERBOSE = 1 if $DEBUG; # debug implies verbose messages
+
+# output the documentation
+if ($HELP) {
+    # output a man page if we can
+    if (ref(Pod::Text->can('new')) eq 'CODE') {
+	# try the new way if appears to exist
+	my $parser = Pod::Text->new(sentence=>0, width=>78);
+	printf STDOUT "\n"; $parser->parse_from_file($0);
+    } else {
+	# else must use the old way
+	printf STDOUT "\n"; Pod::Text::pod2text(-78, $0);
+    };
+    exit(1);
+}
+
+# check for correct arguments present, print usage if errors
+unless ($NOERROR
+	&& scalar(@ARGV) >= 1
+	&& defined($outfile)
+	&& $romtype ne 'NONE'
+    ) {
+    printf STDERR "obj2hex.pl %s by Don North (perl %g)\n", $VERSION, $];
+    print STDERR "Usage: $0 [options...] arguments\n";
+    print STDERR <<"EOF";
+       --help                  output manpage and exit
+       --debug                 enable debug mode
+       --verbose               verbose status reporting
+       --boot                  M9312 boot prom
+       --console               M9312 console/diagnostic prom
+       --binary                binary program load image
+       --ascii                 ascii m9312 program load image
+       --bytes=N               bytes per block on output
+       --nocrc                 inhibit output of CRC-16 in hex format
+       --logfile=LOGFILE       logging message file
+       --outfile=OUTFILE       output .hex/.txt/.bin file
+       OBJFILE...              macro11 object .obj file(s)
+EOF
+    # exit if errors...
+    die "Aborted due to command line errors.\n";
+}
+
+# setup log file as a file, defaults to STDERR if not supplied
+my $LOG = defined($logfile) ? FileHandle->new("> ".$logfile) : FileHandle->new_from_fd(fileno(STDERR),"w");
+
+#----------------------------------------------------------------------------------------------------
+
+# subroutine prototypes
+
+sub trim ($);
+sub chksum (@);
+sub rad2asc (@);
+sub crc (%);
+sub read_rec ($);
+sub parse_rec ($);
+
+#----------------------------------------------------------------------------------------------------
+
+# fill in the parameters of the device
+
+if ($romtype eq 'BOOT') {
+
+    # M9312 512x4 boot prom
+    %excaddr = ( 024=>1, 025=>1 ); # bytes to be skipped in rom crc calc
+    $memsize = 128; # number of instruction bytes allowed
+    $memfill = 0x00; # memory fill pattern
+    $romsize = 512; # number of rom addresses (must be a power of two)
+    $romfill = 0x00; # rom fill pattern
+    $rombase = 0173000; # base address of rom
+
+} elsif ($romtype eq 'DIAG') {
+
+    # M9312 1024x4 diagnostic/console prom
+    %excaddr = ( ); # bytes to be skipped in rom crc calc
+    $memsize = 512; # number of instruction bytes allowed
+    $memfill = 0x00; # memory fill pattern
+    $romsize = 1024; # number of rom addresses (must be a power of two)
+    $romfill = 0x00; # rom fill pattern
+    $rombase = 0165000; # base address of rom
+
+} elsif ($romtype eq 'BINA' || $romtype eq 'ASC9') {
+
+    # program load image ... 56KB address space maximum
+    %excaddr = ( ); # bytes to be skipped in rom crc calc
+    $memsize = 7*8192; # number of instruction bytes allowed
+    $memfill = 0x00; # memory fill pattern
+    $romsize = 8*8192; # number of rom addresses (must be a power of two)
+    $romfill = 0x00; # image fill pattern
+    $rombase = 0; # base address of binary image
+
+} else {
+
+    # unknown ROM type code
+    die "ROM type '$romtype' is not supported!\n";
+
+}
+
+if ($VERBOSE) {
+    printf $LOG "ROM type is '%s'\n", $romtype;
+    printf $LOG "ROM space is %d. bytes\n", $memsize;
+    printf $LOG "ROM length is %d. addresses\n", $romsize;
+    printf $LOG "ROM base address is 0%06o\n", $rombase;
+}
+
+#----------------------------------------------------------------------------------------------------
+
+# read/process the input object file records
+
+# real pdp11 memory data words in boot prom
+my @mem = ((0) x $memsize);
+
+# min/max address limits in object file
+my ($adrmin,$adrmax) = ('','');
+
+# state variables in processing object records
+my $rommsk = ($romsize-1)>>1; # address bit mask
+my $adrmsk = 0xFFFF; # 16b addr mask
+my $datmsk = 0xFFFF; # 16b data mask
+my $memmsk = 0xFF; # 8b memory data mask
+    
+# databases
+my %gblsym = ();
+my %psect = ();
+my @psect = ();
+my %program = ();
+my $psectname = '. ABS.';
+my $psectaddr = 0;
+my $psectnumb = -1;
+my $textaddr = 0;
+
+# program defaults
+$program{START}{VALUE} = 1;
+$program{START}{PSECT} = '. ABS.';
+
+# process all object files
+while (my $objfile = shift(@ARGV)) {
+
+    # open the input .obj file, die if error
+    my $OBJ = FileHandle->new("< ".$objfile);
+    die "Error: can't open input object file '$objfile'\n" unless defined $OBJ;
+
+    # now parse all the records
+    while (my @rec = &read_rec($OBJ)) { &parse_rec(\@rec); }
+
+    # done with object file
+    $OBJ->close;
+}
+
+#----------------------------------------------------------------------------------------------------
+
+# compute CRC if required, copy memory image to output buffer
+
+my @buf = ($romfill) x $romsize; # physical PROM data bytes, filled background pattern
+
+# only compute CRC on M9312 ROMs
+if ($romtype eq 'BOOT' || $romtype eq 'DIAG') {
+
+    # compute CRC-16 of the prom contents (except exception words) and store at last location
+    my $crctab = &crc(-name=>$crctype, -new=>1);
+    my $crc = &crc(-name=>$crctype, -init=>1);
+    for (my $adr = 0; $adr < $memsize-2; $adr += 1) {
+	next if exists($excaddr{$adr}); # skip these addresses
+	$mem[$rombase+$adr] = $memfill unless defined($mem[$rombase+$adr]);
+	$crc = &crc(-name=>$crctype, -table=>$crctab, -crc=>$crc, -byte=>$mem[$rombase+$adr]);
+    }
+    $crc = &crc(-name=>$crctype, -crc=>$crc, -last=>1);
+    unless ($nocrc) {
+	# output computed CRC-16 as last word in the ROM file
+	$mem[$rombase+$memsize-2] = ($crc>>0)&0xFF;
+	$mem[$rombase+$memsize-1] = ($crc>>8)&0xFF;
+    }
+    printf $LOG "ROM %s is %06o (0x%04X)\n", $crctype, ($crc) x 2 if $VERBOSE;
+
+    # process data words to actual PROM byte data
+    # put 4bit nibble in low 4b of each 8b data byte, zero the upper 4b
+    # only copy the above instruction portion over
+    for (my $idx = 0; $idx < $memsize<<1; $idx += 4) {
+	my $dat = ($mem[$rombase+($idx>>1)+1]<<8) | ($mem[$rombase+($idx>>1)+0]<<0);
+	$buf[$idx+0] = ($dat&0xE)|(($dat>>8)&0x1);       # bits   3   2   1   8
+	$buf[$idx+1] = ($dat>>4)&0xF;                    # bits   7   6   5   4
+	$buf[$idx+2] = ((($dat>>8)&0xE)|($dat&0x1))^0xC; # bits ~11 ~10   9   0
+	$buf[$idx+3] = (($dat>>12)&0xF)^0x1;             # bits  15  14  13 ~12
+    }
+
+} elsif ($romtype eq 'BINA' || $romtype eq 'ASC9') {
+
+    # only copy the above instruction portion over
+    for (my $adr = 0; $adr < $memsize; $adr += 1) {
+	$mem[$rombase+$adr] = $memfill unless defined($mem[$rombase+$adr]);
+	$buf[$adr] = $mem[$rombase+$adr];
+    }
+
+}
+
+if ($VERBOSE) {
+
+    # print checksum of entire device
+    my $chksum = 0; map($chksum += $_, @buf);
+    printf $LOG "ROM checksum is %06o (0x%04X)\n", $chksum, $chksum;
+
+}
+
+#----------------------------------------------------------------------------------------------------
+
+# output the linked/processed binary file image in the desired format
+
+my $OUT = FileHandle->new("> ".$outfile);
+die "Error: can't open output file '$outfile'\n" unless defined $OUT;
+
+if ($romtype eq 'BOOT' || $romtype eq 'DIAG') {
+    
+    # output the entire PROM buffer as an intel hex file
+
+    $bytesper = 16 if $bytesper <= 0;
+
+    for (my $idx = 0; $idx < $romsize; $idx += $bytesper) {
+	my $cnt = $idx+$bytesper <= $romsize ? $bytesper : $romsize-$idx; # N bytes or whatever is left
+	my @dat = @buf[$idx..($idx+$cnt-1)]; # get the data
+	my $dat = join('', map(sprintf("%02X",$_),@dat)); # map to ascii text
+	printf $OUT ":%02X%04X%02X%s%02X\n", $cnt, $idx, 0x00, $dat, &chksum($cnt, $idx>>0, $idx>>8, 0x00, @dat);
+    }
+
+    printf $OUT ":%02X%04X%02X%s%02X\n", 0x00, 0x0000, 0x01, '', &chksum(0x0, 0x0000>>0, 0x0000>>8, 0x01);
+
+} elsif ($romtype eq 'BINA') {
+
+    # Loader format consists of blocks, optionally preceded, separated, and
+    # followed by zeroes.  Each block consists of:
+    #
+    #   001		---
+    #   000		 |
+    #   lo(length)	 |
+    #   hi(length)	 |
+    #   lo(address)	 > 'length' bytes
+    #   hi(address)	 |
+    #   databyte1	 |
+    #   :		 |
+    #   databyteN	---
+    #   checksum
+    #
+    # If the byte length is exactly six, the block is the last on the tape, and
+    # there is no checksum.  If the origin is not 000001, then the origin is
+    # the PC at which to start the program.
+
+    $bytesper = 128 if $bytesper <= 0;
+
+    my $start = $program{START}{ADDRESS};
+
+    sub m ($) { $_[0] & 0xFF; }
+
+    # output the entire PROM buffer as a binary loader file
+    for (my $idx = $adrmin; $idx < $adrmax+1; $idx += $bytesper) {
+	my $cnt = $idx+$bytesper <= $adrmax+1 ? $bytesper : $adrmax+1-$idx; # N bytes or whatever is left
+	my @dat = @buf[$idx..($idx+$cnt-1)]; # get the data
+	my $len = $cnt+6;
+	my @rec = (0x01, 0x00, &m($len>>0), &m($len>>8), &m($idx>>0), &m($idx>>8), @dat);
+	print $OUT pack("C*", @rec, &chksum(@rec));
+    }
+    my @end = (0x01, 0x00, 0x06, 0x00, &m($start>>0), &m($start>>8));
+    print $OUT pack("C*", @end, &chksum(@end));
+
+} elsif ($romtype eq 'ASC9') {
+
+    # ascii interface to M9312 console emulator
+
+    sub n ($) { $_[0] & 0xFF; }
+
+    # start program load here
+    printf $OUT "L %o\r\n", $adrmin;
+
+    # output the PROM buffer as an ascii load file
+    for (my $idx = $adrmin; $idx < $adrmax+1; $idx += 2) {
+	printf $OUT "D %06o\r\n", (&n($buf[$idx+1])<<8) | &n($buf[$idx+0]);
+    }
+
+    # start program exec here
+    printf $OUT "L %o\r\nS\r\n", $adrmin;
+
+}
+
+# all done
+$OUT->close;
+
+#----------------------------------------------------------------------------------------------------
+
+# really done
+$LOG->close;
+exit;
+
+#----------------------------------------------------------------------------------------------------
+#----------------------------------------------------------------------------------------------------
+
+# trim leading/trailing spaces on a string
+
+sub trim ($) {
+
+    my ($str) = @_;
+
+    $str =~ s/\s+$//;
+    $str =~ s/^\s+//;
+    
+    return $str;
+}
+
+#----------------------------------------------------------------------------------------------------
+
+# compute checksum (twos complement of the sum of bytes)
+
+sub chksum (@) {
+
+    my $sum = 0;
+
+    map($sum += $_, @_);
+
+    return (-$sum) & 0xFF;
+}
+
+#----------------------------------------------------------------------------------------------------
+
+# RAD50 to ASCII decode
+
+sub rad2asc (@) {
+
+    my @str = split(//, ' ABCDEFGHIJKLMNOPQRSTUVWXYZ$.%0123456789'); # RAD50 character subset
+
+    my $ascii = "";
+    foreach my $rad50 (@_) {
+	$ascii .= $str[int($rad50/1600)%40] . $str[int($rad50/40)%40] . $str[$rad50%40];
+    }
+
+    return $ascii;
+}
+
+#----------------------------------------------------------------------------------------------------
+
+# crc computation routine
+
+sub crc (%) {
+
+    # pass all args by name
+    my %args = @_;
+
+    # all the crcs we know how to compute
+    my %crcdat = ( 'CRC-16' => [ 0xA001,     2, 0x0000,     0x0000     ],
+		   'CRC-32' => [ 0xEDB88320, 4, 0xFFFFFFFF, 0xFFFFFFFF ] );
+
+    # run next byte thru crc computation, return updated crc
+    return $args{-table}[($args{-crc}^$args{-byte}) & 0xFF]^($args{-crc}>>8) if exists($args{-byte});
+
+    # return initial crc value
+    return $crcdat{$args{-name}}->[2] if exists($args{-init});
+
+    # return final crc value xored with xorout
+    return $args{-crc} ^ $crcdat{$args{-name}}->[3] if exists($args{-last});
+
+    # compute the crc lookup table, return a pointer to it
+    if (exists($args{-new})) {
+	my $crctab = [];
+	my $poly = $crcdat{$args{-name}}->[0];
+	foreach my $byte (0..255) {
+	    my $data = $byte;
+	    foreach (1..8) { $data = ($data>>1) ^ ($data&1 ? $poly : 0); }
+	    $$crctab[$byte] = $data;
+	}
+	return $crctab;
+    }
+}
+
+#----------------------------------------------------------------------------------------------------
+
+# read a record from the object file
+
+sub read_rec ($) {
+
+    my ($fh) = @_;
+
+    my ($buf, $cnt, $len, $err) = (0,0,0,0);
+    my @pre = ();
+    my @dat = ();
+    my @suf = ();
+
+    # Object file format consists of blocks, optionally preceded, separated, and
+    # followed by zeroes.  Each block consists of:
+    #
+    #   001		---
+    #   000		 |
+    #   lo(length)	 |
+    #   hi(length)	 > 'length' bytes
+    #   databyte1	 |
+    #   :		 |
+    #   databyteN	---
+    #   checksum
+    #
+
+    # skip over strings of 0x00; exit OK if hit EOF
+    do { return () unless $cnt = read($fh, $buf, 1); } while (ord($buf) == 0);
+
+    # valid record starts with (1)
+    $err = 1 unless $cnt == 1 && ord($buf) == 1;
+    push(@pre, ord($buf));
+
+    # second byte must be (0)
+    $cnt = read($fh, $buf, 1);
+    $err = 2 unless $cnt == 1 && ord($buf) == 0;
+    push(@pre, ord($buf));
+
+    # third byte is low byte of record length
+    $cnt = read($fh, $buf, 1);
+    $err = 3 unless $cnt == 1;
+    $len = ord($buf);
+    push(@pre, ord($buf));
+
+    # fourth byte is high byte of record length
+    $cnt = read($fh, $buf, 1);
+    $err = 4 unless $cnt == 1;
+    $len += ord($buf)<<8;
+    push(@pre, ord($buf));
+
+    # bytes five thru end-1 are data bytes
+    $cnt = read($fh, $buf, $len-4);
+    $err = 5 unless $cnt == $len-4 && $len >= 4;
+    @dat = unpack("C*", $buf);
+
+    # last byte is checksum
+    $cnt = read($fh, $buf, 1);
+    $err = 6 unless $cnt == 1;
+    my $rcv = ord($buf);
+    push(@suf, ord($buf));
+
+    # output the record if debugging
+    if ($DEBUG) {
+	my $fmt = "%03o";
+	my $n = 16;
+	my $pre = sprintf("RECORD: [%s] ",join(" ",map(sprintf($fmt,$_),@pre)));
+	printf $LOG "\n\n%s", $pre;
+	my $k = length($pre);
+	my @tmp = @dat;
+	while (@tmp > $n) {
+	    printf $LOG "%s\n%*s", join(" ",map(sprintf($fmt,$_),splice(@tmp,0,$n))), $k, '';
+	}
+	printf $LOG "%s", join(" ",map(sprintf($fmt,$_),@tmp)) if @tmp;
+	printf $LOG " [%s]\n\n", join(" ",map(sprintf($fmt,$_),@suf));
+    }
+
+    # check we have a well formatted record
+    die sprintf("Error: invalid object file record format (%d)", $err) if $err;
+
+    # compare rcv'ed checksum vs exp'ed checksum
+    my $exp = &chksum(0x01, $len>>0, $len>>8, @dat);
+    die sprintf("Error: Bad checksum exp=0x%02X rcv=0x%02X", $exp, $rcv) unless $exp == $rcv;
+
+    # all is well, return the record
+    return @dat;
+}
+
+#----------------------------------------------------------------------------------------------------
+
+# parse an input object file record, update data structures
+
+sub parse_rec ($) {
+
+    my ($rec) = (@_);
+
+    # type is first byte of record
+    my $key = $rec->[0];
+
+    if ($key == 001) { # GSD
+
+	# iterate over GSD subrecords
+	for (my $i = 2; $i < scalar(@$rec); ) {
+	    # GSD records are fixed 8B length all in the same format
+	    my $nam = &rad2asc(($rec->[$i+1]<<8)|($rec->[$i+0]<<0), ($rec->[$i+3]<<8)|($rec->[$i+2]<<0));
+	    my $flg = $rec->[$i+4];
+	    my $ent = $rec->[$i+5];
+	    my $val = ($rec->[$i+7]<<8)|($rec->[$i+6]<<0);
+	    my @ent = ('MODULE','CSECT','INTSYM','XFRADR','GBLSYM','PSECT','IDENT','VSECT');
+	    if ($ent == 3) {
+		# XFRADR
+		$program{START}{PSECT} = $nam;
+		$program{START}{VALUE} = $val;
+	    } elsif ($ent == 4) {
+		# GBLSYM flags
+		$gblsym{$nam}{FLG}{$flg&(1<<0) ? "WEA" : "STR"}++;
+		$gblsym{$nam}{FLG}{$flg&(1<<3) ? "DEF" : "REF"}++;
+		$gblsym{$nam}{FLG}{$flg&(1<<5) ? "REL" : "ABS"}++;
+		$gblsym{$nam}{PSECT} = $psectname;
+		$gblsym{$nam}{VALUE} = $val;
+	    } elsif ($ent == 5) {
+		# PSECT flags
+		$psect[++$psectnumb] = $nam;
+		$psect{$nam}{NUMBER} = $psectnumb;
+		$psect{$nam}{FLG}{$flg&(1<<0) ? "GBL" : $flg&(1<<6) ? "GBL" : "LCL"}++;
+		$psect{$nam}{FLG}{$flg&(1<<2) ? "OVR" : "CAT"}++;
+		$psect{$nam}{FLG}{$flg&(1<<4) ? "R/O" : "R/W"}++;
+		$psect{$nam}{FLG}{$flg&(1<<5) ? "REL" : "ABS"}++;
+		$psect{$nam}{FLG}{$flg&(1<<7) ? "D"   : "I/D"}++;
+		if ($psect{$nam}{FLG}{CAT}) {
+		    $psect{$nam}{LENGTH} = $val;
+		    $psect{$nam}{START} = $psectaddr;
+		    $psectname = $nam;
+		    $psectaddr += $val;
+		} elsif ($psect{$nam}{FLG}{ABS}) {
+		    $psect{$nam}{LENGTH} = $val;
+		    $psect{$nam}{START} = 0;
+		    $psectname = $nam;
+		}
+	    }
+	    if ($DEBUG) {
+		printf $LOG "..GSD: type='%-6s'(%03o) name='%s' value=%06o", $ent[$ent], $ent, $nam, $val;
+		printf $LOG " flags=%s", join(",", sort(keys(%{$gblsym{$nam}{FLG}}))) if $ent == 4;
+		printf $LOG " flags=%s", join(",", sort(keys(%{$psect{$nam}{FLG}}))) if $ent == 5;
+		printf $LOG "\n";
+	    }
+	    $i += 8;
+	}
+
+    } elsif ($key == 002) { # ENDGSD
+
+	# just say we saw it
+	printf $LOG "..ENDGSD\n" if $DEBUG;
+
+	$program{END}{ADDRESS} = 0;
+	foreach my $nam (sort(keys(%psect))) {
+	    my $start = $psect{$nam}{START};
+	    my $length = $psect{$nam}{LENGTH};
+	    my $end = $length ? $start + $length - 1 : $start;
+	    $program{END}{ADDRESS} = $end if $end > $program{END}{ADDRESS};
+	    printf $LOG "..PSECT[%d](%s) START=%06o END=%06o LENGTH=%06o\n",
+	                $psect{$nam}{NUMBER}, $nam, $start, $end, $length if $length && $DEBUG;
+	}
+	$program{START}{ADDRESS} = $program{START}{VALUE} + $psect{$program{START}{PSECT}}{START};
+	printf $LOG "..PROG(ADDRESS) START=%06o END=%06o\n",
+	            $program{START}{ADDRESS}, $program{END}{ADDRESS} if $DEBUG;
+
+    } elsif ($key == 003) { # TXT
+
+	# process text record
+	my $off = ($rec->[3]<<8)|($rec->[2]<<0);
+	my $len = scalar(@$rec)-4;
+	my $base = $psect{$psectname}{START};
+	my $adr = ($base + $off) & $adrmsk;
+	foreach my $i (1..$len) { $mem[$adr+$i-1] = $rec->[4+$i-1]; }
+	if ($DEBUG) {
+	    printf $LOG "..TXT OFFSET=%06o LENGTH=%o BASE=%06o PSECTNAME='%s'\n", $off, $len, $base, $psectname;
+	    for (my $i = 0; $i < $len; $i += 2) {
+		printf $LOG "      %06o: ", ($adr+$i)&~1 if $i%8 == 0;
+		printf $LOG " %03o...", $mem[$adr+$i++] if ($adr+$i)&1;
+		printf $LOG " %06o", ($mem[$adr+$i+1]<<8)|($mem[$adr+$i+0]<<0) if $i < $len-1;
+		printf $LOG " ...%03o", $mem[$adr+$i] if $i == $len-1;
+		printf $LOG "\n" if $i%8 >= 6 && $i < $len-2;
+	    }
+	    printf $LOG "\n";
+	}
+	$adrmin = $adr        if $adrmin eq '' || $adr        < $adrmin;
+	$adrmax = $adr+$len-1 if $adrmax eq '' || $adr+$len-1 > $adrmax;
+	$textaddr = $adr;
+
+    } elsif ($key == 004) { # RLD
+
+	# iterate over RLD subrecords
+	for (my $i = 2; $i < scalar(@$rec); ) {
+	    # first byte is entry type and flags
+	    my $ent = $rec->[$i+0] & 0x7F; # entry type
+	    my $flg = $rec->[$i+0] & 0x80; # modification flag (0=word, 1=byte)
+	    # process an entry
+	    if ($ent == 001) {
+		# internal relocation ... OK
+		my $dis = $rec->[$i+1];
+		my $con = ($rec->[$i+3]<<8)|($rec->[$i+2]<<0);
+		# process
+		my $adr = $adrmsk & ($textaddr + $dis - 4);
+		my $val = $datmsk & ($psect{$psectname}{START} + $con);
+		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
+		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
+		printf $LOG "..RLD(IR):   adr=%06o val=%06o ; dis=%06o con=%06o\n",
+		            $adr, $val, $dis, $con if $DEBUG;
+		$i += 4;
+	    } elsif ($ent == 002) {
+		# global relocation ... TBD <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
+		my $dis = $rec->[$i+1];
+		my $nam = &rad2asc(($rec->[$i+3]<<8)|($rec->[$i+2]<<0), ($rec->[$i+5]<<8)|($rec->[$i+4]<<0));
+		# process
+		printf $LOG "..RLD(GR):   dis=%06o nam='%s'\n",
+		            $dis, $nam if $DEBUG;
+		$i += 6;
+	    } elsif ($ent == 003) {
+		# internal displaced ... OK
+		my $dis = $rec->[$i+1];
+		my $con = ($rec->[$i+3]<<8)|($rec->[$i+2]<<0);
+		# process
+		my $adr = $adrmsk & ($textaddr + $dis - 4);
+		my $val = $datmsk & ($con - ($adr+2));
+		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
+		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
+		printf $LOG "..RLD(ID):   adr=%06o val=%06o ; dis=%06o con=%06o\n",
+		            $adr, $val, $dis, $con if $DEBUG;
+		$i += 4;
+	    } elsif ($ent == 004) {
+		# global displaced relocation ... TBD <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
+		my $dis = $rec->[$i+1];
+		my $nam = &rad2asc(($rec->[$i+3]<<8)|($rec->[$i+2]<<0), ($rec->[$i+5]<<8)|($rec->[$i+4]<<0));
+		# process
+		printf $LOG "..RLD(GDR):  dis=%06o nam='%s'\n",
+		            $dis, $nam if $DEBUG;
+		$i += 6;
+	    } elsif ($ent == 005) {
+		# global additive relocation ... TBD <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
+		my $dis = $rec->[$i+1];
+		my $nam = &rad2asc(($rec->[$i+3]<<8)|($rec->[$i+2]<<0), ($rec->[$i+5]<<8)|($rec->[$i+4]<<0));
+		my $con = ($rec->[$i+7]<<8)|($rec->[$i+6]<<0);
+		# process
+		printf $LOG "..RLD(GAR):  dis=%06o con=%06o nam='%s'\n",
+		            $dis, $con, $nam if $DEBUG;
+		$i += 8;
+	    } elsif ($ent == 006) {
+		# global additive displaced relocation ... TBD <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
+		my $dis = $rec->[$i+1];
+		my $nam = &rad2asc(($rec->[$i+3]<<8)|($rec->[$i+2]<<0), ($rec->[$i+5]<<8)|($rec->[$i+4]<<0));
+		my $con = ($rec->[$i+7]<<8)|($rec->[$i+6]<<0);
+		# process
+		printf $LOG "..RLD(GADR): dis=%06o con=%06o nam='%s'\n",
+		            $dis, $con, $nam if $DEBUG;
+		$i += 8;
+	    } elsif ($ent == 007) {
+		# location counter definition ... OK
+		my $dis = $rec->[$i+1];
+		my $nam = &rad2asc(($rec->[$i+3]<<8)|($rec->[$i+2]<<0), ($rec->[$i+5]<<8)|($rec->[$i+4]<<0));
+		my $con = ($rec->[$i+7]<<8)|($rec->[$i+6]<<0);
+		# process
+		$psectname = $nam;
+		$textaddr = $datmsk & ($con);
+		printf $LOG "..RLD(LCD):  adr=%06o            ; dis=%06o con=%06o nam='%s'\n",
+		            $textaddr, $dis, $con, $nam if $DEBUG;
+		$i += 8;
+	    } elsif ($ent == 010) {
+		# location counter modification ... OK
+		my $dis = $rec->[$i+1];
+		my $con = ($rec->[$i+3]<<8)|($rec->[$i+2]<<0);
+		# process
+		$textaddr = $datmsk & ($con);
+		printf $LOG "..RLD(LCM):  adr=%06o            ; dis=%06o con=%06o\n",
+		            $textaddr, $dis, $con if $DEBUG;
+		$i += 4;
+	    } elsif ($ent == 011) {
+		# program limits ... OK, mostly
+		my $dis = $rec->[$i+1];
+		# process
+		my $adr = $adrmsk & ($textaddr + $dis - 4);
+		my $val = $datmsk & ( 01000 ); # make this up, no easy way to compute it
+		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
+		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
+		printf $LOG "..RLD(LIM1): adr=%06o val=%06o ; dis=%06o\n",
+		            $adr, $val, $dis if $DEBUG;
+		$dis += 2;
+		$adr += 2;
+		$val = $datmsk & ($program{END}{ADDRESS});
+		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
+		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
+		printf $LOG "..RLD(LIM2): adr=%06o val=%06o ; dis=%06o\n",
+		            $adr, $val, $dis if $DEBUG;
+		$i += 2;
+	    } elsif ($ent == 012) {
+		# psect relocation ... OK
+		my $dis = $rec->[$i+1];
+		my $nam = &rad2asc(($rec->[$i+3]<<8)|($rec->[$i+2]<<0), ($rec->[$i+5]<<8)|($rec->[$i+4]<<0));
+		# process
+		my $adr = $adrmsk & ($textaddr + $dis - 4);
+		my $val = $datmsk & ($psect{$nam}{START});
+		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
+		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
+		printf $LOG "..RLD(PR):   adr=%06o val=%06o ; dis=%06o nam='%s'\n",
+		            $adr, $val, $dis, $nam if $DEBUG;
+		$i += 6;
+	    } elsif ($ent == 014) {
+		# psect displaced relocation ... OK
+		my $dis = $rec->[$i+1];
+		my $nam = &rad2asc(($rec->[$i+3]<<8)|($rec->[$i+2]<<0), ($rec->[$i+5]<<8)|($rec->[$i+4]<<0));
+		# process
+		my $adr = $adrmsk & ($textaddr + $dis - 4);
+		my $val = $datmsk & ($psect{$nam}{START} - ($adr+2));
+		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
+		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
+		printf $LOG "..RLD(PDR):  adr=%06o val=%06o ; dis=%06o nam='%s'\n",
+		            $adr, $val, $dis, $nam if $DEBUG;
+		$i += 6;
+	    } elsif ($ent == 015) {
+		# psect additive relocation ... OK
+		my $dis = $rec->[$i+1];
+		my $nam = &rad2asc(($rec->[$i+3]<<8)|($rec->[$i+2]<<0), ($rec->[$i+5]<<8)|($rec->[$i+4]<<0));
+		my $con = ($rec->[$i+7]<<8)|($rec->[$i+6]<<0);
+		# process
+		my $adr = $adrmsk & ($textaddr + $dis - 4);
+		my $val = $datmsk & ($psect{$nam}{START} + $con);
+		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
+		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
+		printf $LOG "..RLD(PAR):  adr=%06o val=%06o ; dis=%06o con=%06o nam='%s'\n",
+		            $adr, $val, $dis, $con, $nam if $DEBUG;
+		$i += 8;
+	    } elsif ($ent == 016) {
+		# psect additive displaced relocation ... OK
+		my $dis = $rec->[$i+1];
+		my $nam = &rad2asc(($rec->[$i+3]<<8)|($rec->[$i+2]<<0), ($rec->[$i+5]<<8)|($rec->[$i+4]<<0));
+		my $con = ($rec->[$i+7]<<8)|($rec->[$i+6]<<0);
+		# process
+		my $adr = $adrmsk & ($textaddr + $dis - 4);
+		my $val = $datmsk & ($psect{$nam}{START} + $con - ($adr+2));
+		$mem[($adr+0)&$adrmsk] = $memmsk & ($val>>0);
+		$mem[($adr+1)&$adrmsk] = $memmsk & ($val>>8);
+		printf $LOG "..RLD(PADR): adr=%06o val=%06o ; dis=%06o con=%06o nam='%s'\n",
+		            $adr, $val, $dis, $con, $nam if $DEBUG;
+		$i += 8;
+	    } elsif ($ent == 017) {
+		# complex relocation ... OK
+		my $dis = $rec->[$i+1];
+		my $nam = '. ABS.';
+		my $con = 0;
+		# process
+		my $adr = $adrmsk & ($textaddr + $dis - 4);
+		my $loc = 0;
+		my $val = 0;
+		my $opc = "";
+		my @stk = ();
+		my $dun = 0;
+		for ($i += 2; !$dun; $i += 1) {
+		    if ($rec->[$i] == 000) {
+			$opc = "NOP";
+		    } elsif ($rec->[$i] == 001) {
+			my @arg = splice(@stk,-2,2);
+			push(@stk, $arg[0] + $arg[1]);
+			$opc = "ADD";
+		    } elsif ($rec->[$i] == 002) {
+			my @arg = splice(@stk,-2,2);
+			push(@stk, $arg[0] - $arg[1]);
+			$opc = "SUB";
+		    } elsif ($rec->[$i] == 003) {
+			my @arg = splice(@stk,-2,2);
+			push(@stk, $arg[0] * $arg[1]);
+			$opc = "MUL";
+		    } elsif ($rec->[$i] == 004) {
+			my @arg = splice(@stk,-2,2);
+			push(@stk, $arg[1] == 0 ? 0 : int($arg[0] / $arg[1]));
+			$opc = "DIV";
+		    } elsif ($rec->[$i] == 005) {
+			my @arg = splice(@stk,-2,2);
+			push(@stk, $arg[0] & $arg[1]);
+			$opc = "AND";
+		    } elsif ($rec->[$i] == 006) {
+			my @arg = splice(@stk,-2,2);
+			push(@stk, $arg[0] | $arg[1]);
+			$opc = "IOR";
+		    } elsif ($rec->[$i] == 007) {
+			my @arg = splice(@stk,-2,2);
+			push(@stk, $arg[0] ^ $arg[1]);
+			$opc = "XOR";
+		    } elsif ($rec->[$i] == 010) {
+			my @arg = splice(@stk,-1,1);
+			push(@stk, -$arg[0]);
+			$opc = "NEG";
+		    } elsif ($rec->[$i] == 011) {
+			my @arg = splice(@stk,-1,1);
+			push(@stk, ~$arg[0]);
+			$opc = "COM";
+		    } elsif ($rec->[$i] == 012) {
+			my @arg = splice(@stk,-1,1);
+			$val = $arg[0];
+			$opc = "STO";
+			$dun = 1;
+		    } elsif ($rec->[$i] == 013) {
+			############## may need tweaking ################
+			my @arg = splice(@stk,-1,1);
+			$val = $arg[0];
+			$opc = "STO+DIS";
+			$dun = 1;
+		    } elsif ($rec->[$i] == 016) {
+			############## may need tweaking ################
+			$nam = &rad2asc(($rec->[$i+2]<<8)|($rec->[$i+1]<<0),
+					($rec->[$i+4]<<8)|($rec->[$i+3]<<0));
+			$con = $gblsym{$nam}{VALUE};
+			push(@stk, $con);
+			$opc = sprintf("GLB[%s]=(%o)", &trim($nam), $con);
+			$i += 4;
+		    } elsif ($rec->[$i] == 017) {
+			$nam = $psect[$rec->[$i+1]];
+			$con = ($rec->[$i+3]<<8) | ($rec->[$i+2]<<0);
+			$loc = $psect{$nam}{START} + $con;
+			push(@stk, $loc);
+			$opc = sprintf("FET[%s+%o]=(%o)", &trim($nam), $con, $loc);
+			$i += 3;
+		    } elsif ($rec->[$i] == 020) {
+			$con = ($rec->[$i+2]<<8) | ($rec->[$i+1]<<0);
+			push(@stk, $con);
+			$opc = "CON";
+			$i += 2;
+		    }
+		    $stk[-1] = $datmsk & $stk[-1] if @stk;
+		    printf $LOG "....OPC=%-20s STK=(%s)\n", $opc, join(",",map(sprintf("%o",$_),@stk)) if $DEBUG;
+		}
+		printf $LOG "..RLD(CMPX): adr=%06o val=%06o ; dis=%06o\n", $adr, $val, $dis if $DEBUG;
+	    } else {
+		die sprintf("Error: Unknown RLD entry 0%o (%d)", $ent, $ent);
+	    }
+	}
+
+    } elsif ($key == 005) { # ISD
+
+	# ignore
+	printf $LOG "..ISD: ignored\n" if $DEBUG;
+
+    } elsif ($key == 006) { # ENDMOD
+
+	# just say we saw it
+	printf $LOG "..ENDMOD\n\n\n" if $DEBUG;
+
+    } elsif ($key == 007) { # LIBHDR
+
+	# ignore
+	printf $LOG "..LIBHDR: ignored\n" if $DEBUG;
+
+    } elsif ($key == 010) { # LIBEND
+
+	# ignore
+	printf $LOG "..LIBEND: ignored\n" if $DEBUG;
+
+    } else { # unknown
+
+	# invalid record type in the object file
+	die sprintf("Error: unknown record type 0%o (%d)", $key, $key);
+
+    }
+
+    return;
+}
+
+#----------------------------------------------------------------------------------------------------
+
+# the end