HDTenEightyP/NetNews huggingface dataset:
From: Alexander M. Rosenberg <alexr@apple.com>
Subject: Re: MacIntercomm (finally a real comm program)
X-Useragent: Nuntius v1.1.1d12
Date: Mon, 12 Oct 1992 18:36:10 GMT
X-Xxdate: Mon, 12 Oct 92 19:36:02 GMT
X-Xxmessage-Id: <A6FF13A21A040C7C@mtdew.apple.com>
Organization: Hackers Anonymous

In article <1992Oct9.064613.22521@daffy.cs.wisc.edu> Glenn Howes,
howes@cat15.cs.wisc.edu writes:
>How does it manage to use CTB file transfer tools? You would think that a
>file transfer tool might call a routine that moves memory every now and
>again. This would not be a problem in the normal course of events, but
>at interupt time a definite no-no.

It can't. File Transfer tools currently can only be called in a synchronous
fashion from an application-level event loop.

We're looking at making it possible to call a File Transfer tool in an
asynchronous fashion. If you have any suggestions, let me know.
---------------------------------------------------------------------------
-  Alexander M. Rosenberg  - INTERNET: alexr@apple.com      - Yoyodyne    -
-  330 Waverley St., Apt B - UUCP:ucbvax!apple!alexr        - Propulsion  -
-  Palo Alto, CA 94301     -                                - Systems     -
-  (415) 329-8463          - Nobody is my employer so       - :-)         -
-  (408) 974-3110          - nobody cares what I say.       -             -
From: mike_steiner@qm.claris.com (Mike Steiner)
Newsgroups: comp.sys.mac.comm
Subject: Re: Two modems at the same time ?
Date: 13 Oct 92 22:43:26 GMT
Followup-To: comp.sys.mac.comm

In article <D2150035.g0m2da@outpost.SF-Bay.org>, peirce@outpost.SF-Bay.org
(Michael Peirce) wrote:
> 
> 
> In article <1be73iINNkn9@usenet.INS.CWRU.Edu> (comp.sys.mac.comm), ar660@cleveland.Freenet.Edu (Pasi Korhonen) writes:
> > 
> > Anybody ever tried using two modem on the same machine, in different ports,
> > different phone lines, different term progs ?  Or same prg, and switch ports ?
> > How's it gonna work ? Potential troubles ? One possible use could be having
> > a faxmodem receiving faxes from another line and have a data modem session on
> > the other. Comments ?
> 
> What's the problem?  I've done this many times.  I usually have uAccess
> running using the modem port.  Often I want to check my AppleLink or America
> Online while uAccess is talking on the modem line, so I dial out using my
> TelePort modem (not using either serial port).  Works great.  And I still
> have printer port to use for AppleTalk.
> 
> The only problem I can see you having is a shortage of serial ports
> since there are only two standard ones (and AppleTalk takes one if
> you are using that - or a serial printer).  The TelePort modem is
> one solution since it uses the ADB. Another is a third party serial card.
> As long as your program use the Comm Toolbox (so you can access the
> port) your all set (the TelePort also supports a fake-out-the-printer-port
> mode so that you can pretend it's using the printer port even when
> AppleTalk is already using it - good for non-CTB program like APPLELINK :-(

What I found that doesn't work well at all is calling from one modem to the
other modem on the same computer.  I tried that when testing my BBS a few
years ago.

+---------------------------------------------------------------------+
|Now that I have a reader that can do .sigs, I can't think of a witty |
|one to put here, so I won't.  All normal disclaimers apply.          |
+---------------------------------------------------------------------+
Newsgroups: comp.sys.mac.comm
From: Tim <lt10@cornell.edu>
Subject: FaxSTF (Pro?)
X-Xxdate: Sat, 17 Oct 92 00: 50:30 GMT
Nntp-Posting-User: lt10@cornell.edu
Organization: Cornell University
X-Useragent: Nuntius v1.1.1d7
Date: Sat, 17 Oct 1992 04:23:18 GMT


Newsgroups: comp.sys.mac.comm
From: sgruby@jarthur.claremont.edu (Scott Allen Gruby)
Subject: MacTCP Problems
Followup-To: comp.sys.mac.comm
Organization: Harvey Mudd College, Claremont, CA 91711
Date: Sat, 10 Oct 1992 01:08:51 GMT

I am having a problem with what I assume is a MacTCP problem. We have two
Mac labs here and in one of the labs, six of the Macs have problems. What
happens is if we open up Telnet or MacIP and open a connection to either
our UNIX machine or one of our VAXstations, the connection opens and then
immediately closes. There is a workaround by opening a connection to one of
the workstations and telnetting over to the UNIX or VAX, but this is not a
solution.

I am pretty sure that I have everything configured properly in MacTCP in
terms of the nameserver, gateway, IP address, etc.

Does anyone know what I am doing wrong?

Please respond via email.

Thanks.

Scott Allen Gruby
sgruby@jarthur.claremont.edu
Newsgroups: comp.sys.mac.comm
From: Nigel Jessup <NJessup@compserv.amc.edu.au>
Subject: Help wiith Fetch please
X-Xxdate: Wed, 14 Oct 92 20:28:06 GMT
Organization: Australian Maritime College
X-Useragent: Nuntius v1.1.1d9
Date: Wed, 14 Oct 92 02:24:44 GMT

Cheers folks
			I'm having some probs with Fetch. We have only recently gone 'online'
to the internet. Fetch works very well for us. Trougble is I can only
reach two other sites apart from our own unix machine, they are archie.au
and one of the machines at the University next door. Our Mac's go from
atalk through a Webster multiport gatway to ethernet to fiber and out
from there. I can ftp to anywhere using the unix machine without any
probs, but this is not as easy s going direct with Fetch. 
			The Uni next door have no trouble using Fetch to other sites. Please
email any suggestions you may have.

Regards from Down Under
						Nigel
#########################
Nigel Jessup
NJessup@compserv.amc.edu.au
Australian Maritime College
Launceston Tasmania 7248
#########################
Newsgroups: comp.sys.mac.comm
From: tel@adimail.uucp (Terry Monks)
Subject: PowerBook 100
Organization: Automata Design, Inc.
X-Newsreader: TIN [version 1.1 PL6]
Date: Fri, 16 Oct 1992 17:23:25 GMT


If anyone has been successful running a modem at 2400
baud from the printer port of a Powerbook 100 would they
please contact me, either by telephone at (703) 742-9400,
or by email at adimail!tel.

If anyone has been unsuccessful at this, would they also
contact me.

My Powerbook 100 (2/20) has been back to Apple twice for
motherboard swaps in attempts to fix this problem, to no
avail, and I have heard form two other people about
similar problems. On the other hand, the service was
very fast.

Please do not respond with advice to turn off AppleTalk,
MIDI, change modems, change cables, or change software.
All this has been tried ad nauseam.

-- 
Terry Monks        Automata Design Inc    (703) 742-9400

Newsgroups: comp.sys.mac.comm
From: Ken Cunefare
Subject: Re: macTCP problem - Crashes unattended Mac
Organization: Mechanical Engineering
Distribution: usa
Date: Fri, 9 Oct 1992 13:43:20 GMT

One more time, but let's select national distribution, shall we?

>I am trying this again, as there was probably a glitch in my intitial
>configuration, such that I have no idea where my first postin ended up, and
any
>responses may have been lost, too.
>
>>Some time ago, my Mac IIci with a Rocket accelerator began exhibiting rather
>>obnoxious behavior. If left unattended for about 10 minutes, it would lock
up,
>>with no recourse other than rebooting. Through a rather time consuming
>process,
>>I determind that macTCP was the source of the problem. Now, I had been using
>>macTCP for an extended period of time prior to the appearance of the problem,
>>so I suspect that it had somehow become damaged. Replacing the file with a
new
>>copy of macTCP cured the problem.
>>
>>My question: Have you encounted such difficulties with macTCP? If so, were
you
>>able to determine the source of the problem, that is, what damaged macTCP? Do
>>you know of any incompatibilities between macTCP and other inits/extensions,
>>etc?
>>
>>Please e-mail me you responses to:
>>kc21@hydra.gatech.edu
>
>or
>
>ken.cunefare@me.gatech.edu
>
>>Thanks in advance. I'll summarize and post the results.
>>
>>Ken Cunefare
>>Georgia Institute of Technology
>>
>
>
>


Newsgroups: comp.sys.mac.comm
From: tinsel@uiuc.edu (Thomas Aaron Insel)
Subject: Re: Anybody got a "Ph" server?
Originator: tai50080@uxa.cso.uiuc.edu
Reply-To: tinsel@uiuc.edu
Organization: Masticating Illini
Date: Mon, 12 Oct 1992 22:51:43 GMT
Keywords: eudora protocol ph

poorman@convex.com (Peter Poorman) writes:

> Eudora includes a "Ph" client, which is apparently intended to get people's
> phone numbers by contacting a server.  

> Can someone tell me where to get a server (to run on my UNIX box)?

qi is the ph server program, ftp-able from uxc.cso.uiuc.edu in /net/qi.
-- 
Thomas Insel (tinsel@uiuc.edu)
  "Behind every argument is someone's ignorance." -- Louis D. Brandeis
From: Mark.Tucker@f421.n109.z1.fidonet.org (Mark Tucker)
Sender: Uucp@blkcat.UUCP
Newsgroups: comp.sys.mac.comm
Subject: Re: SYSTEM 7 SHARING & APPLE SHARE
Date: Thu, 08 Oct 1992 12:57:22 -0500

 > Does anybody know what are the differences between the sharing 
 > option on
 > system 7 and Apple Share 3.0 ?
 > 
 > Do they perfom the same as servers ? (I'm planing to serve at least 
 > 10
 > persons).
 > Are there any speckmarks out there?

System 7 has a limit of 10 ten users connected at the same time.  AppleShare 3.0
allows 120.  AppleShare also offers better administration tools, including the
ability to send messages from the server.  Here are some specs from the
AllpeShare 3.0 manual.
Maximum connected users:  120 (default to 50)
Maximum number of open files:  346
Maximum number of volumes:  50
Maximum number of shared imens:  50
Maximum number of users in a user/group file:  8192 ( 2000 recommended)
Maximum number of groups in a user/group file:  8192 (2000 recommended)
Maximum number of group memberships per user:  42
Maximum number of simultaneous file launches:  up to 120 (depends on application
and connected users)
Maximum number of Apple II network startups:  40
Hope this helps.


Newsgroups: comp.sys.mac.comm
From: jbailey@world.std.com (james d bailey)
Subject: Re: MacIntercomm (finally a real comm program)
Organization: The World Public Access UNIX, Brookline, MA
Date: Sat, 10 Oct 1992 03:30:31 GMT

howes@cat15.cs.wisc.edu (Glenn Howes) writes:

>In article <BvuA5H.J5x@news.udel.edu> johnston@me.udel.edu (Bill Johnston) writes:
>>In article <BvtyrI.F7F@world.std.com> jbailey@world.std.com (james d bailey) writes:
>>>time@ice.com (Tim Endres) writes:
>>
>>>>Does MI work under A/UX? Does it use the CTB?
>>>
>>>MacIntercomm does use the CTB if you want.  This shows a high level of
>>>compatibilty since the CTB is anything but stable.  I don't own AUX so
>>>I don't know about that.

>How does it manage to use CTB file transfer tools? You would think that a
>file transfer tool might call a routine that moves memory every now and
>again. This would not be a problem in the normal course of events, but
>at interupt time a definite no-no.

[sig deleted]

As far as I know it only uses the connection(?) tools.  Transfers are
supported by the program itself, XYZModem and kermit.
From: peirce@outpost.SF-Bay.org (Michael Peirce)
Newsgroups: comp.sys.mac.comm
Subject: Re: MacIntercomm (finally a real comm program)
Date: 9 Oct 92 17:06:33 GMT
Article-I.D.: outpost.D2150035.flv0pw
Reply-To: peirce@outpost.SF-Bay.org (Michael Peirce)
Organization: Peirce Software
X-Mailer: uAccess - Macintosh Release: 1.6v1


In article <1992Oct8.233419.14095@muddcs.claremont.edu> (comp.sys.mac.comm), jam@jupiter.claremont.edu (Jay Margolis) writes:
>
>                                           MacIntercomm is MUCH more able  
> to be compatible with future hardware and system software, not less.  They  
> depend on neither the hardware nor the system software, but rather the  
> code that is part of the program.

Huh?  This doesn't really make any sense.  If they don't access the
serial port directly (accessing the hardware) or use the operating
system to do it, how do they send any data?

The ONLY way to stay compatable is to use the operating system.  This
isn't just some far away future.  PowerPC based Macs aren't that far
away and they do include a few little changes from current Macs :-)

--  Michael Peirce      --   peirce@outpost.SF-Bay.org
--  Peirce Software     --   Suite 301, 719 Hibiscus Place
--                      --   San Jose, California USA 95117
--  Makers of...        --   voice: (408) 244-6554 fax: (408) 244-6882
--            SMOOTHIE  --   AppleLink: peirce & America Online: AFC Peirce
From: wsanders@ffeine.Sun.COM (Wiley Sanders)
Newsgroups: comp.sys.mac.comm
Subject: Re: Are System 6.0.8 and System 7.0.1 Appleshares Compatible?
Date: 7 Oct 1992 16:34:21 GMT
Organization: Tradeshow Tech Support
Distribution: usa
NNTP-Posting-Host: ffeine.corp.sun.com

Thanks to all who responded. The System7 powerbook is now happily
serving files to the System6 Plus. Cool. 

-wiley

--
"True love is learning to love your lover's obsessions,
or at least being able to say '...oh...that's nice...'"
                                                        -Greg Brown
From: jbailey@world.std.com (james d bailey)
Newsgroups: comp.sys.mac.comm
Subject: Re: MacIntercomm (finally a real comm program)
Date: 9 Oct 92 01:33:06 GMT
Organization: The World Public Access UNIX, Brookline, MA

jam@jupiter.claremont.edu (Jay Margolis) writes:
>Tim:

>All I have to say to this is that I run a fair share of inits.  I have had  
>not a single problem.  I run the program on my Quickmail server with tons  
>of inits sometimes and have never had it crash.  I have run it on a Plus,  
>and various other machines on my network without difficulty.  In fact, it  
>is one of only two programs that doesn't freeze up when the hardware  
>handshaking is locked on the direct connections here (other is ZTerm).   
>I've tried them ALL.

>I've used it on System 6 and System 7.  The weirdest thing happened when I  
>used it on System 6.  The program actually made itself look like it was  
>running in System 7.  From what I've seen, this program doesn't depend AT  
>ALL on the system version you are running and is almost entirely  
>independent of the Macintosh toolbox (I've tried researching how they are  
>doing their thing with a debugger).  If this is the case, virtually  
>nothing you could do would screw up MacIntercomm.  When I saw their demo  
>at the Expo, one of the demoers said that they had even seen cases when  
>the foreground application had crashed during a transfer and it kept  
>going.  I thought this was dubious, so I tested it.  Sure enough, in a few  
>(not all) of my tests, the transfer even kept going after a crash of  
>another program.  This is exactly the kind of UNIX-like stability that the  
>Mac has never had until now.  

>-Jay

I'm a fan of MacIntercomm, but this is going overboard.  MacIntercomm 
is using interrupts to preempt.  This means that as long as interrupts
are enabled and the system is not totally wedged it will continue to run.
But a crash is just as likely to leave interrupts disabled and do you
really want to be writing to your disk when the system is in an unstable
state.  I wouldn't rely on this 'feature' too heavily, you might regret it.
From: chip@interzone.ch
Newsgroups: comp.sys.mac.comm
Subject: re: tmpnewdmp.0xfdeae029
Date: 11 Oct 92 14:43:06 GMT
X-Mailer: rnMac Buggy, I mean Beta, Test Version


tempdump
Newsgroups: comp.sys.mac.comm
From: summeral@ucsu.Colorado.EDU (SUMMERALL  ELMINA LANIER)
Subject: ARA Bug
Summary: My Plus crashes every time the ARA client disconnects...
Organization: University of Colorado, Boulder
Date: Fri, 16 Oct 1992 00:14:15 GMT

Everytime someone completes an ARA session on my plus (4 megs, sys 7.0 *) it
crashes.  Anyone have any idea why?  It is using a Zoom 9600 baud modem with
the Zoom ara driver.

Thanks,
Thomas Summerall

Newsgroups: comp.sys.mac.comm
From: leonardr@netcom.com (Leonard Rosenthol)
Subject: Re: Atob Conversion
Organization: Netcom - Online Communication Services  (408 241-9760 guest) 
Date: Fri, 16 Oct 1992 18:09:06 GMT

In article <17058.2ADEA3A0@zeus.ieee.org> Mike.Lavery@f204.n2603.z1.ieee.org (Mike Lavery) writes:
>  Though atob and btoa is mentioned in the Comm faq, there is no mention 
>of any Mac application to convert atob format.  Other than Clipboard 
>Magician, which I can get to handle only text, does such an application 
>running on a Macintosh (not under UNIX)  exist?
>  
	StuffIt Deluxe 3.0 includes a Translator (one of our plug-ins) for
handling atob/btoa conversion, as well as many other Unix, Mac & PC encoding
and compression/archiving standards.

-- 
-----------------------------------------------------------------------------
Leonard Rosenthol			Internet: 	leonardr@netcom.com
Director of Advanced Technology		AppleLink:	MACgician
Aladdin Systems, Inc.			GEnie:		MACgician
From: cubsfan@cultnet.ch (wrobel)
Newsgroups: comp.sys.mac.comm
Subject: accessing dialcom from internet
Date: Tue, 13 Oct 92 19:47:13 GMT
Organization: CULTNET Communication Systems for Art & Science

Does anyone out there know how to access a network called "dialcom"?
All the person whom I want to reach can tell me is his address "ctd004"
and that it is on "system 64".  I'm on an internet node is Switzerland.
E-mail, please, I don't usually monitor this forum.  Thanks.

.......................................................................
Internet: cubsfan@cultnet.ch
CULTNET (SWITZERLAND) E.V.
INTERNATIONAL COMMUNICATION SYSTEMS FOR ART AND SCIENCE
.......................................................................
From: Glen.Stewart@f175.n2240.z1.ieee.org (Glen Stewart)
Newsgroups: comp.sys.mac.comm
Subject: RE: Re: TCP/IP thru ARA Possible?
Date: 7 Oct 92 18:57:41 GMT
Organization: FidoNet node 1:2240/175 - The Associati, Grand Blanc MI

Are you saying that running ARA on my Mac will also give me MacTCP, thereby
making it InterNet-accessible?  Could you strighten me out?  Thanks!









--  
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
 Glen Stewart - Internet: Glen.Stewart@f175.n2240.z1.ieee.org
Xref: sparky comp.sys.mac.comm:9766 comp.sys.mac.programmer:16600
Date: Wednesday, 7 Oct 1992 11:53:55 +01
Newsgroups: comp.sys.mac.comm,comp.sys.mac.programmer
Subject: Re: ICMP
From: Andre' Pirard <pirard@vm1.ulg.ac.be>
X-UserAgent: Nuntius v1.1.1d11
X-XXMessage-ID: <A6F87C6D0201180A@ampa.segi.ulg.ac.be>
X-XXDate: Wed, 7 Oct 92 10:37:17 GMT
Distribution: world
Organization: Universite' de Lie`ge (Belgium)

In article <BvMr7F.1ys@news.cso.uiuc.edu> Pete Resnick,
resnick@cogsci.uiuc.edu writes:
>for power users. I find, for example, Eudora's method of reporting:
>
>"ICMP destination unreachable. This may or may not be important."
>
>confusing to the average uninformed user, and certainly not telling
>the user when it *is* important and what to do if so (i.e. cancel,
>continue).

Perfectly right ;-) Seeing the (French translated) message "An ICMP
message was receive. This ...", a paniced brave lady phoned and told me
that about any message she receives *is* important.
However, I wouldn't blame Eudora, she copes perfectly well with all the
rest.

On the more serious technical side, the other remark is true.
A program may shorten the time to *open* a connection by receipt of
ICMP(s), but it certainly must let the user decide whether to close one
that's open or to give him a chance to go to the machine room and fix the
cable instead.

-----
Andre Pirard          SEGI, Univ. de Li`ge         139.165 IP coordinator
B26 - Sart Tilman     B-4000 Li`ge 1 (Belgium)            +32 (41) 564932
pirard@vm1.ulg.ac.be  alias PIRARD@BLIULG11.BITNET
Xref: sparky comp.sys.mac.comm:9818 comp.sys.mac.wanted:9292
From: noah@cad.gatech.edu (Noah White)
Newsgroups: comp.sys.mac.comm,comp.sys.mac.wanted
Subject: Forsale VersaTerm
Date: 8 Oct 1992 19:05:38 GMT
Organization: Georgia Institute of Technology, CAE/CAD Lab
Distribution: world
Reply-To: Noah.White@cad.gatech.edu
NNTP-Posting-Host: goldeneye.cad.gatech.edu


  I have a copy of VersaTerm with upgrade order form and docs. I'd like
$35 for it and I'll pick up the shipping on it.

-Noah

Newsgroups: comp.sys.mac.comm
From: Steven 'Wild Man' Wong <opus@arco.com>
Subject: High speed connection to international location
Organization: ARCO Exploration and Production Technology
X-Useragent: Nuntius v1.1
Date: Wed, 7 Oct 1992 22:02:16 GMT

I am trying to transfer data between two Macs on a fairly regular
basis.  The files can get into the megabyte range.  One of the Macs
is in Jakarta, Indonesia.  Because long distance charges can be
expensive and existing phone lines are fairly noisy, I would like a
semi-dedicated line for the data transmission.  I have been told that
a balance between a costly dedicated T1 connection and the public
phone system is a switched 56Kbps digital line where you pay only for
the time you use.  Assuming that one can be routed to Jakarta,

1)  Can AppleTalk Remote work over such a line? 
2)  What kind of modem would be required on either end?

If ARA cannot be used, can an Apple Talk network be set up with such
a line? If so, what are the software and hardware requirements and
associated costs?

Please respond via e-mail.

Steven 'Wild Man' Wong                         Phone: (214) 754-6472
ARCO Exploration and Production Technology     FAX:   (214) 754-3281
2300 W. Plano Pkwy                             e-mail: opus@arco.com
Plano, TX  75075
Newsgroups: comp.sys.mac.comm
From: ar4@sage.cc.purdue.edu (Piper Keairnes)
Subject: Magic 14.4k baud modem
Organization: Purdue University
Distribution: na
Date: Thu, 8 Oct 1992 18:27:46 GMT

I just received the Magic V.32bis modem from MacProducts last night. The
documentation is good, hardware handshaking cable included, QuickLink II
software included.

The QuickLink II disk has a bad sector making the software unusable.

I am using ZTerm and am having a couple problems connecting long distance
and locally. The Magic modem has a 30-day moneyback guarantee, so if I can't
fix all of my problems then there is no harm in returning it.

Problem list:
   1) While on a local 9600/V.32 line connection, I periodically get a
      NO CARRIER while in the middle of doing stuff. I do have call waiting,
      but I've set the loss of carrier condition to 10 seconds as
	  recommended and the phone isn't ringing after the loss of carrier
	  (which makes me think it's not Call Waiting). Note: we do not have the
	  *70 prefix in our area.
   2) Downloads interrupted midway typically lead to a loss of control over
      the conenction.
   3) Connection to a WorldBlazer results in about a 9600 baud connection at
      most. Can this be improved? The connection says it's 14.4k/v.42.

Does anyone have suggestions to fixing these problems?

-- 
Piper Keairnes - Computer Science   ** PUCC Consultant for money. **
INTERNET: ar4@sage.cc.purdue.edu    **   Mac programmer for fun.  **
From: Jerrod@Lilly.Com (Jerrod T. Carter)
Newsgroups: comp.sys.mac.comm
Subject: Re: What is a tar'red archive and can my Mac read it?
Date: 9 Oct 92 20:17:40 GMT
Distribution: world,local
Organization: Eli Lilly & Company
X-UserAgent: Nuntius v1.1.1d11X-XXMessage-ID: <A6FB524DFE020103@venus.d46.lilly.com>X-XXDate: Fri, 9 Oct 92 20:14:21 GMTLines: 17

In article <1b2ht4INNgj0@sequoia.ccsd.uts.EDU.AU> Chris Chesher,
  cchesher@uts.edu.au writes:
>It seems many ftp sites use a compression format called tar (suffix is
>".z"). How can I translate these files (I've tried all decompresion
>systems I can, and postscript certainly doesn't understand). 

A tar'd archive and a .Z file are two different things, but they
both come from Unix. A tar'd file is a way of placing a whole
directory structure in one file. This is accomplished with the 'tar'
command on a Unix system. On FTP servers, it is common to then
compress these files so that they don't take up as much room (tar
does not do this). This is done with the 'compress' command.

As for a utility to undo it on a Mac, there probably is, but I don't
know what it would be: I use a Unix system when I need those files.

jerrod