I've added "$dump_log=>setpassCat.dumplog" to "my $cs =".   With a bit of luck, perusing the dump_log and input_log should help me work out remaining problems.
    cheers,
    Don
    striving for Perl Adept
    (it's pronounced "why-bick")

Update: It's still quite kludgy, but the following scriptlet *does* work.   8^D   The next order of business is to replace the or die's with if(){} for all the $cs -> sections, so Net::Telnet can deal directly with timeouts and such.   I expect to then find that the waitfor()</t>'s need further tweaking.

#!/usr/bin/perl -w

# setpassCat.pl
# February 26-27, 2001

use strict;
use Net::Telnet::Cisco;

my $target  = '';
my $oldpass = '';
my $olden   = '';
my $newpass = '';

umask oct 177;

my $cs = Net::Telnet::Cisco->new (
    host      =>"$target",
    errmode   =>'return',
    timeout   =>'30',
    input_log =>'setpassCat.inlog',
    )                                      or die "  Error connecting 
+to $target: $!";


$cs->login('',$oldpass)                    or die "  Error logging in 
+to $target: $!";
print $cs -> last_prompt, "\n";
$cs->enable($olden)                        or die "  Error getting pri
+vilaged mode at $target: $!";
print $cs -> last_prompt, "\n";

my @cmd_output = $cs->cmd('set pass');
print (@cmd_output)                        or die "Error giving \"set 
+pass\" command: $!";
print $cs -> last_cmd, "\n";

$cs ->waitfor('/Enter old password: /')    or die "Error getting \"Ent
+er old password\" prompt: $!";
print $cs -> last_prompt, "\n";
@cmd_output = $cs -> cmd($oldpass);
print (@cmd_output)                        or die "Error giving \"old 
+password\": $!";

$cs ->waitfor('/Enter new password: /')    or die "Error getting \"Ent
+er new password\" prompt: $!";
print $cs -> last_prompt, "\n";
@cmd_output = $cs -> cmd($newpass);
print (@cmd_output)                        or die "Error giving \"new 
+password\": $!";

$cs ->waitfor('/Retype new password: /')   or die "Error getting \"Ret
+ype new password\" prompt: $!";
print $cs -> last_prompt, "\n";
@cmd_output = $cs -> cmd($newpass);
print (@cmd_output)                        or die "Error giving \"Rety
+pe new password\": $!";

$cs ->waitfor('/Password changed./')       or die "Error getting \"Pas
+sword changed\" statement: $!";
print $cs -> last_prompt, "\n";
@cmd_output = $cs -> cmd('disa');
print (@cmd_output)                        or die "Error leaving privi
+laged mode: $!";
print $cs -> last_prompt, "\n";

$cs -> close;
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