NTP for Macintosh is a set of software components that synchronize the system clock of the Macintosh with other computers in a network. NTP for Macintosh is based upon the Internet standard Network Time Protocol, Version 2, as described in RFC 1119. This protocol is widely used within the TCP/IP community. The protocol features high reliability, low overhead, and can provide accuracy to 232 picoseconds. The protocol distributes time in a tree topology using clients, servers, peers, and broadcast technology.
NTP for Macintosh is implemented as a pair of Control Panel devices (containing a pair of corresponding system extensions and one device driver) for the Macintosh Operating System, and optional software for Apple╒s A/UX and DEC╒s VAX/VMS operating systems. NTP for Macintosh can use either AppleTalk (DDP), or IP (UDP), or both, as the transport protocol. These protocols are used for their extremely low overhead. The NTP upper level protocol is error resistant and is intended to work with datagram╨oriented transport protocols. It can work effectively even in congested networks.
NTP for Macintosh is a suite of software and accompanying documentation. This shareware distribution contains only the NTP Client software and minimal documentation (this file). The remainder of the software is described in the executive summary, included with this distribution, and with the documentation available from the author.
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Both the NTP Client and NTP Server for the Macintosh Operating System support the following features.
Ñ Implements Version 2 of the Network Time Protocol algorithms; interoperable with both Version 3 and Version 1 implementations
Ñ Works on any model Macintosh running System 6.0.5 or later software (it is System 7 friendly). Any Macintosh can be a client as well as a server. It has been tested on all released System versions from 6.0.5 to 7.5.
Ñ Compatible with AppleTalk Phases 1 and 2 (LocalTalk, EtherTalk, and TokenTalk)
Ñ Runs quietly, asynchronously in the background; never ties up the Macintosh
Ñ Supports balloon help (System 7 only) for all dialogs and controls
Ñ 32-bit clean
Ñ AppleTalk transition event aware
Ñ Compatible with dial-in AppleTalk products such as AppleTalk Remote Access (ARA), Liaison, and Timbuktu
Ñ Compatible with other servers such as Apple╒s AppleShare, Microsoft╒s Mail Server, and CE Software╒s QuickMail
Ñ PowerManager aware for PowerBooks and Portables
Ñ Virtual Memory compatible (System 7 only)
Ñ Supports MacTCP and any supported link access protocols including Ethernet, SL/IP, LocalTalk, EtherTalk, and others. It has been tested with all released versions of MacTCP from 1.0.2 to 2.0.6.
Ñ Allows you to synchronize your machine to a corporate (local) time standard or to a national time standard (such as WWV managed by NIST, via the Internet)
Ñ Extremely easy to configure. Configurations can be created and locked; distributing pre-configured software around a campus is easy.
Ñ Current implementation maintains accuracy to ▒1.9 seconds
Ñ API provides services for other applications (time stamps, time conversion, UTC offset, DST values, clock synchronization status and performance, etc.)
NTP Client
Ñ The NTP client, server, and broadcast server modes (3, 4, and 5) are supported; the symmetric and reserved modes (1, 2, 6, and 7) are not currently implemented
Ñ Supports communication with one server and/or one broadcast server
Ñ Automatically compensates for the local offset from UTC (GMT) based upon geographic location as set by the Map Control Panel
Ñ Automatically adjusts the clock to account for any local Daylight Saving Time policy using easy to configure dialogs
NTP Server
Ñ The server (MacOS) software supports NTP, DATE (UDP only) as described in RFC 867, and TIME (UDP only) as described in RFC 868
Ñ Can serve any number of clients
Ñ Can be configured to provide broadcast NTP service
Ñ Can be optionally configured as a primary (stratum 1) server for isolated networks
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Macintosh OS System 6.0.5 or later is required. MultiFinder is not needed. The software provided in this distribution will ÑnotÑ run under A/UX.
Make sure that the name for the Macintosh has been set. In System 6 this is set via the Chooser in the field ╥User Name.╙ In System 7 this is set via the ╥Sharing Setup╙ Control Panel, in the ╥Macintosh Name╙ field.
Make sure that AppleTalk is ╥Active╙ in the Chooser (both System 6 and System 7).
Set the geographic location. To set the geographic location of the Macintosh for both System 6 and 7, use the Map Control Panel.
If TCP/IP will be used, make sure that MacTCP, V1.0.2 or later, is properly installed. Proper operation has been verified up through V2.0.6 of MacTCP (now called ╥TCP/IP Connection for Macintosh╙).
If you are upgrading from a previous version of NTP Client, simply replace the NTP Client already present in your Control Panels folder (System 7) or System Folder (System 6) and restart the Macintosh. You are done with installation and can skip the remainder of this section; the selected server and configuration options are retained.
Insert the NTP for Macintosh distribution floppy into your floppy drive and double click on the floppy icon to open the disk. Drag the NTP Client icon onto your System Folder. (System 7 users will be asked if the file should be placed in the Control Panels folder, which it should.) Open the Control Panel from the Apple menu and select the NTP Client.
Select a network protocol to use. If you will be using an NTP time server over AppleTalk, make sure the ╥AppleTalk╙ Network Protocol is selected. Alternatively, if you will be using an NTP time server over an IP network, make sure the ╥TCP/IP╙ Network Protocol is selected.
Make sure the option ╥Enable at StartUp╙ is selected. If you would like to see the startup icon for the NTP Client when the Macintosh is booted, select the option ╥Show icon at StartUp.╙
Configure the software for the local Daylight Saving Time policy. Click ╥DST Settings╔╙ to bring up the first of three dialogs. In the first dialog, if your locale does not observe Daylight Saving Time, click ╥is not╙ and dismiss the dialog by clicking ╥OK╙. If your locale does observe Daylight Saving Time, click ╥is╙; adjust the hours:minutes:seconds offset to the correct value by clicking on a part and adjusting that part up or down using the arrows to the right. (The correct value for the United States is 1:00:00.) When done, click ╥More╔╙ Now configure the software for the starting and ending dates for Daylight Saving Time. By default, the correct values for the United States are shown. If this is correct, click ╥More╔╙ in the second dialog, and ╥OK╙ in the third dialog. (Note that it is important for users in areas that support Daylight Saving Time to go through all three dialogs and verify the configuration once.)
Configure the software for a time server. If you are setting up an NTP Client to receive broadcast messages only (i.e., do not directly poll a server), skip this paragraph and go on to the next. Otherwise, click ╥Servers╔╙. If using AppleTalk, servers in the current zone are shown. All zones in the AppleTalk internetwork are available through the pop-up menu. Select a zone and server by either double clicking on the server or pressing ╥Select╙. If using MacTCP, hosts in the Hosts file (of your System Folder, not the Control Panels folder) are shown. If no hosts are displayed, either edit the Hosts file to contain the name and address of the server you want to use or use the ╥New╔╙ button to manually enter the name of a host. In the Servers dialog, select an IP server by either double clicking on the host name or pressing ╥Select╙. When finished, click ╥Done╙. If you are unsure where the NTP server(s) is(are) in your network or need help editing the Hosts file, please contact your local network administrator.
If your installation uses broadcast NTP services (either IP or AppleTalk) select the ╥Accept Broadcasts╙ option to permit receipt of these packets.
After the NTP Client has been configured correctly, close the NTP Client Control Panel. Restart your Macintosh by selecting the ╥Restart╙ item from the ╥Special╙ menu of the Finder. After the machine has restarted, you can watch the progress of the NTP Client from the Control Panel. If the software is correctly configured and communications are established, the Macintosh should begin to synchronize with the server in about four minutes.
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Release V1.00
This was the original release, September 17, 1993.
Release V1.01
The second release was October 3, 1994. The following changes were made from the previous release.
Fixed bug where IP broadcast reception might not be enabled under the following conditions: IP protocols selected and either no IP server is defined or one whose name could not be resolved into an address. Startup will now make sure that IP broadcast reception is turned on, if requested, even if there is no other IP host to poll. Note however that the broadcast server ÑmustÑ be sending either V1 or V2 NTP packets for the NTP Client to accept and process them.
The NTP Client Control Panel now responds to the Edit menu Cut, Copy, and Clear commands. Clear does the obvious thing. Cut and Copy place an ISO 8601 formatted local date and time string into the Clipboard.
Minor compatibility changes, code optimization, and better internationalization to the NTP Client Control Panel, system extension, and server selection dialog.
Made sure the system extension closes the resolver, if used, when it is finished.
Added some keyboard equivalents to some of the NTP Client Control Panel dialog items. However System 7 does not use any of these; System 6 users might be able to use them.
Dramatic speed improvement when building the AppleTalk zones menu of the Server Selection dialog. Speed should now be competitive with the Chooser.
Underline the Macintosh╒s home zone in the pop-up menu of the server selection dialog. Also place a check mark next to the zone currently being examined.
A number of significant bugs fixed in the Get Info dialog of the Server Selection dialog, particularly in the TCP/IP handling code. Eliminated orphaned dialog and memory leaks.
Now use styled text in some of the help balloons. Also better hot point for some of the help balloons in the NTP Client Control Panel. Improved help and dialog text.
More robust interface to DNR resources.
Add configuration capability to suppress all error messages encountered during system boot. This is important for machines that dial-in and use ARA for remote IP service. There is no user interface for this yet; see me for details.
Updated and expanded the list of restricted stratum 1 IP hosts for changed IP addresses and new servers. This is based upon clock.txt dated July 7, 1994.
Fixed a bug in the system extension related to the size of the driver unit table.
Compatibility with CE Software╒s CEToolbox has been improved (this may be true for other commercial packages as well). It is no longer necessary to rename CEToolbox and place it in the System Folder.
LATE BREAKING NEWS: After brief testing, it appears that NTP Client works correctly in ╥compatibility mode╙ on the Power Macintosh series. There are no plans at this time to create either a ╥fat binary╙ or native mode code for the Power Macintosh.
Release V1.02
The third release was February 11, 1995. The following changes were made from the previous release.
Eliminate a double free handle error in the preferences saving code.
I was using the wrong index to get the DST icon displayed in the Control Panel. This caused nothing to be displayed during DST. (This was the result of a last minute change in V1.01; V1.00 worked correctly.)
Fixed a free handle error with the resource bit set when closing the Control Panel.
The preferences file name is now locked from changes by the Finder when the file is first created. (Old preferences files will be left unchanged.)
The NTP Client and NTP Server now maintain separate password resources.
The default button is correctly outlined upon update in the password dialog. Also in that dialog, OK is only enabled with there is password text present and visual feedback is given for keyboard equivalents of OK and Cancel.
BIG CHANGE: Modified the password dialog filter function to eliminate any characters typed with the control key. This will make it impossible for users of previous versions to unlock their configurations with this version.
As reported by Scott Gustafson, the INIT was crashing when IP broadcasting only service was selected (with no polled IP server). This has been fixed.
Fix a problem reported by David T. Witkowski: the Control Panel does not always get refreshed correctly after other NTP Client dialogs have obscured the main Control Panel.
Added a new dialog to the Server Selection dialog triggered by the ╥New╔╙ button. This dialog allows the users to enter an IP host manually (rather than having to rely on the hosts file). The new host is added to the ╥Available Servers╙ list, scrolled to, highlighted, and the other dialog buttons set appropriately.
Major cleanup to the layout of the ╥Get Info...╙ dialog. Fixes to the ╥Get Info╔╙ dialog code: only call UDPBfrReturn when there is data in the response packet; more reliable method for determining a valid response from a poll.
Make sure that the Server Selection dialog can only select one server (in the Available Servers list) at a time.
Fixed a minor resource leak that could occur if the ╥Get Info╔╙ button appeared to be pressed but no server was selected in the Available Servers list of the Server Selection dialog.
Replaced most references to ╥Daylight Savings Time╙ with ╥Daylight Saving Time╙ as pointed out by Thomas Gunter. I didn╒t get all references yet because the layout of some of the dialogs is so painful to alter that I haven╒t updated them yet. Will do so in the future, though.
Allow NTP V3 packets to pass the version check. This was intended to allow V3 broadcast packets though, but actually allows V3 packets to get processed in any mode. This comes at the suggestion of Scott Gustafson.
Fixed one of the boot time error messages from ╥isproperly╙ to ╥is properly╙.
Display the bracket around the network protocol buttons in 50% gray if the dialog is not in color.
Made the height of the scrolling boxes in the Server Selection dialog a multiple of 16, plus 2. This really gives much better visual results with the Chicago 12 point system font.
Added spinning watch animated cursor resources and general routines to allocate, spin, and deallocate the cursors. Add support for these in routines with long setup or operation times.
Fixed a bug in the behavior of the DST configuration pop-up menu: when popping up two or more times, the menu would not pop up to the current selection (however the saved value in the preferences was always correct). Now the menu always pops up to the current selection. Fixed a minor resource leak. The ╥More╔╙ button was not dimmed when first entering the dialog if DST is not observed; fixed.
Modified the bounding box on the ╥Broadcast:╙ label in the Control Panel. The colon was getting cropped off. I don't know when this started but it was present in at least the previous release.
Fixed bugs in the Server Selection dialog for AppleTalk: any server with the same name as the selected server (in any zone) would not appear. Also, it was previously possible to select more than one server from the available servers list; this has been disabled.
The balloon help text for precision, dispersion, and poll in the Get Info dialog has been updated to be more accurate. The balloon help text for the time source and address fields has also been updated for legibility. The balloon help text for dispersion in the main Control Panel has been updated for accuracy.
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Over a year and a half of development and testing have gone into the first release of NTP for Macintosh. The goal has been to develop a product that delivers the features, performance, and reliability that users need for quality time service. However, in spite of this work, a number of incompatibilities have been discovered. As always, the author is committed to eliminating any and all incompatibilities where possible. Below is a list of the current known incompatibilities and their workarounds, if any.
Microsoft Mail and DAL won╒t play together. So what has this got to do with NTP for Macintosh? Well, the interaction is so violent that NTP for Macintosh is prevented from running. Try running either Microsoft Mail or DAL, but not both. NTP for Macintosh may be used with either.
When booting a machine that has the Microsoft Mail Server installed, and holding down the ╥M╙ key to temporarily disable loading of the Mail Server, NTP Client will also fail to load. There is no currently known workaround.
In order for the broadcast mechanism of AppleTalk to work, a fixed socket must be used. This implementation uses socket 123 (the same as the UDP port number) which is in the statically assigned, unrestricted experimental use range. This service is valuable enough that it is (in the author╒s opinion) worthwhile to use a fixed socket and hope that Apple will allocate a fixed socket for this purpose in the future. However, for the present, if you have any applications that make use of this socket or others in the reserved experimental range, you will experience difficulty. (The author is only familiar with one commercial application that uses these sockets: Timbuktu from Farallon. You can prevent Timbuktu from interfering with the NTP Client by disabling the use of socket 123 in Timbuktu. See Appendix B of the Timbuktu manual for further details.)
When running under System 7 Pro, make sure the button marked ╥Daylight Savings Time╙ is left unchecked in the Date & Time Control Panel. The .NTP driver does not currently trust the operating system to reliably indicate when Daylight Saving Time is in effect (or not). Better to tell the system you are always on standard time and let the driver determine the effectiveness of Daylight Saving.
The ╥Offset╙ field of the Get Info╔ dialog is still not filled in after polling a server.
As of V1.02 of NTP Client, the password protection dialog has changed slightly. Control characters are no longer allowed as part of the password. If you have locked a configuration using a password that contains control characters, you will not be able to unlock it with NTP Client, V1.02 or later. Use an earlier version to unlock the configuration. Then use the current version to lock the configuration using a new password that does not contain control characters.
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When using MacTCP, the domain name resolver will only list a few of the hosts in the Hosts file. The number of hosts listed seems to be, in part, a function of the amount of memory installed in the system. Make sure the host that you will be using for a server is listed near the beginning of this file. MacTCP is not capable of supporting IP broadcast networks which use a hostid portion of the destination address of all 0s; a hostid of all 1s can be used. This is (usually) only an issue for networks where older Suns are in use.
The NTP Client is prevented from accessing any of the known Internet stratum 0 and 1 servers. The Macintosh is simply not accurate enough to deserve this benefit. This is an intentional restriction.
The NTP Client must load after MacTCP during the boot sequence if IP protocols are going to be used.
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This distribution contains the following items: NTP Client software, TeachText README file, and an executive summary in PostScript. If the distribution that you have does not contain exactly these items, then the distribution may have been altered! The executive summary file contains a 7 page summary of the NTP for Macintosh product line.
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The NTP Client software is available as shareware for a suggested price of $25, in U.S. funds, per copy. (For your own protection, please do not send cash. Some form of check is your best bet.) Please make your check payable to John Dundas. Upon payment of the shareware fee, you will receive one copy of the User╒s Manual (a 90 page manual that describes all of the available software including the servers for Macintosh, A/UX, and VAX/VMS), will become a registered user, and will be notified of future upgrades to the software. Site licensing and volume discounts are available; contact the author for details.
The NTP Server software for the Macintosh, A/UX, and VAX/VMS operating systems is available at a modest price directly from the author.
For more details, contact the author at:
John Dundas
P.O. Box 50784
Pasadena, CA 91115-0784
dundas@netcom.com
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This document, and the software it describes, are ⌐Copyright 1992-1995 by John A. Dundas III. All rights reserved.
This software is being distributed as ╥shareware.╙ This has a number of implications. Try the software. If you like or need the function that it performs, use it. If you use the software, send in the shareware fee. If you don╒t use it, erase the software from your machine. You may not rent, lease, or otherwise charge a use fee for this software or its accompanying documentation. If you give a copy of the software to someone else, you must give them an unaltered copy of the original distribution. You are not authorized to alter and distribute this software in any way. You are on your honor to follow these guidelines. Recipients of this software are bound by the same shareware principles.
If this software becomes mission critical to your facility, you are advised to obtain the distribution directly from the author. In this way you are assured of an uncorrupted original distribution.
Note to employees of the Jet Propulsion Laboratory: Please do not send in your shareware fee. I am an employee of JPL and while this software was not developed using Lab resources and is in no way connected with JPL, NASA, Caltech, or my work at JPL, it is a conflict of interest for me to accept money from the Lab for this product. (Unfortunately this also means that you won╒t be able to obtain the manual or any of the servers.) For JPL use only, the NTP Client may be used for free. If you use it in any venture outside of JPL, however, its use is subject to the terms of shareware. For the same reasons given previously, I cannot accept calls requesting support during business hours.
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You use this software at your own risk. While every effort has been made to insure that the software is both bug and virus free, under no circumstances will the author be held liable for any damages that may occur either directly or indirectly from the use of this software. If these terms and conditions are unacceptable to you, do not use this software.
This software is provided ╥as is╙ without any warranty of any kind. The author expressly disclaims all warranties, either expressed or implied, including but not limited to, implied warranties of merchantability and fitness for any particular purpose, with respect to the software and the accompanying documentation.
In no event shall the author be liable for any damages whatsoever (including, without limitation, damages for loss of business profits, business interruption, loss of business information, or other pecuniary loss) arising out of the use or inability to use this product.
