HyperCom
Volume Number: 7
Issue Number: 6
Column Tag: Tools of the Trade
HyperCom: HC 2.0 Networking
By Dave Kelly, MacTutor Editorial Board
HyperCom™: HyperCard 2.0 Network
Communications the easy way!
HyperCard has invaded the AppleTalk network with HyperCom™ 2.0 from GAVA
Corporation. HyperCom is so easy to use that it seems like a natural part of HyperTalk.
In fact, HyperCom is a set of extendable XCMDs and XFCNs that take care of all the
details of network communications. All that’s left for you is to develop your own
HyperTalk scripts to create network software for nearly any purpose.
The best thing about HyperCom is how much fun you can have with it.
Programming with HyperCom is not a drudgery; it doesn’t leave you with hours trying
to figure how to get it to work. It’s simplicity is the key. There is only one XCMD that
is used to communicate with other HyperCom users over AppleTalk.
HyperCard 2.0’s ability to open multiple windows at the same time makes it
possible to use HyperCom’s XCMDs and XFCNs without moving them to your stack. You
can set up your stack to include the HyperCom stack in the current inheritance path by
using the HyperTalk command:
start using stack HyperCom
This statement allows you to access handlers in the HyperCom stack without
having to modify your Home stack or your copy of HyperCard.
HyperCom has one command, “Tell”. “Tell” has three special forms that can be
used to find the names of other registered HyperCom users. 1) tell who puts a delimited
list of all HyperCom users on the network into “the result”. Your scripts can evaluate
the list in “the result” to decide who you want to send your message to. 2) tell whom
shows a pop-up menu with all the HyperCom users listed. It returns the selected user
name in “the result”. 3) tell whol brings up a dialog box with a list of all HyperCom
users on the network. One or more users may be selected and returned in “the result”.
Once you know who you will be sending the message to, you use “Tell” and the
name (or names) of the users and send your message or messages. In my example, I use
tell whol to ask for a network user.
tell whol,,”Set clock of which Mac:”
Then I use the following lines to tell the user to execute the XCMD “SetTimeDate”
installed in the user’s stack.
--1
put the result into them
put the seconds into standardtime
tell them, "SetTimeDate", standardtime
The purpose of my example is to use HyperCom communications to synchronize
the clock on every computer on the network with a single computer. Since HyperCard
doesn’t have a command to set the clock, I made one. The Pascal source code is included
at the end of this column. After the XCMD is compiled and installed into a stack,
clicking on a single button brings up the user list to select which users’ clock you want
to set. Then the script gets the time from the HyperTalk seconds function and sends it
to the user with the command to use the SetTimeDate XCMD to set the clock.
Each copy of HyperCom is serialized and set up for a specific number of users.
The basic HyperCom package supports 2 users, but there is technically no limit on the
number of users. HyperCom has been used at sites with as many as 600 users over
several zones. Some schools have 40-50 users on a single zone. HyperCom does not get
slowed down with more users. Yet, it makes sense that if the implementation uses a
single server, where the server seeks information and sends it back to the requesting
station, that the speed would be affected. Of course, then, the speed is dependent on how
long it takes to process each query. Database types of applications with 10-20 users
are not uncommon. HyperCom does queue up messages, and allows long scripts to
execute new messages to be executed by calling “Tell” in the body of the handler.
Because the limitation with HyperCom is not with the network traffic, speed problems
can be solved by distributing the data or processing on several machines, or using
faster processors.
GAVA also provides other XCMDs and XFCNs that can be used to extend the
capabilities of HyperCom. These are very useful efficiency savers. For example, with
the sendResource XCMD, the SetTimeDate XCMD could be sent to the user, used to set the
clock, then deleted when done. I don’t have the sendResource XCMD so I couldn’t try it.
The sendFileXCMD sends files over the network. The sendSound XCMD sends a sound to
be played by the receiving machine. Other commands include sendCard, sendClipboard,
sendScreen and the question XFCN to evaluate expressions on a remote Macintosh.
The manual for HyperCom is brief (29 pages) and get right to the point, but
since the commands are simple not much explanation is required. It does a good job in
telling what the tell command does, but it leaves out a few minor details. For example,
it didn’t say what to expect if the user didn’t select any users, but used the cancel
button instead. Since HyperCom is simple to use, these omissions can be figured out
without too much trouble.
There are some sample stacks included with HyperCom. On of the examples is a
network checkers game. My son really loved that one. The examples were designed to
give you some ideas of what HyperCom can do.
HyperCom is ideally suited for anyone that needs network communication
capability in HyperCard. Happy Networking!
HyperCom™ is available from:
GAVA Corporation
1001 4th Ave Plaza, Suite 3200
Seattle, WA. 98154
Phone: 800-767-0647 or 206-223-4282
FAX 206-223-0653
AppleLink GAVA
InterNet: GAVA@ applelink. apple.com
CompuServe: 76174,221
GENIE: GAVA
Prices:
HyperCom 2.0 (for 2 users) $99.95
HyperCom 2.0 with HyperCard 2.0 $129.95
Additional license for HyperCom $50.00
Zone license for HyperCom $499.95
sendFile XCMD $35.00, sendSound XCMD $35.00
sendCard XCMD $35.00, sendClipboard $35.00
sendScreen XCMD $35.00, question XFCN $35.00
sendResource XCMD $35.00
Requires: a Macintosh computer with System 6.0.5 or newer, 1MB RAM and a
hard disk.
SOFTWARE UPDATES
Be sure to check for upgrades to your applications. Many of these are already
available on AppleLink, America On-Line and other services. Some of the new versions
which have been available for some time now are: Now Utilities version 2.0.3, Suitcase
II version 1.2.9, and QUED/M 2.09.
{ HyperCard SetTimeDate XCMD }
{ by Dave Kelly }
unit SetTimeDateUnit;
{ This project handles the SetTimeDate command }
interface
uses
{include the HyperCard interfaces in the XFCN/CMD}
HyperXCmd;
procedure main (paramPtr: XCmdPtr);
{ the entry point for the XCMD/XFCN }
implementation
procedure main;
procedure Fail (errMsg: Str255);
{ return a given error message to HyperCard }
begin
paramPtr^.returnValue := PasToZero(paramPtr, errMsg);
{Set return value of the paramBlock to given message. }
exit(main); {exit the routine }
end;
procedure Setthetime (paramPtr: XCmdPtr);
var
str: str255;
TheTimeDate: longint;
Error: OSErr;
begin
if (paramPtr^.paramCount <> 1) then
Fail('%bad parameters');
ZeroToPas(paramPtr, paramPtr^.params[1]^, str);
{ convert the location to a string }
TheTimeDate := StrToNum(paramPtr, str);
{ and thence to a longint }
Error := SetDateTime(TheTimeDate);
{ if the handle is empty, then return an error}
if Error <> noErr then
Fail('DateTime not changed!');
end;
begin
Setthetime(paramPtr);
{entry point; call the Setthetime routine}
end;
end.
STACK SCRIPT:
-- This product is for licensed HyperCom™ users only
on openstack
global userchecktime
start using stack HyperCom
tell who
put the result into card field "HyperCom Users
put the seconds into userchecktime
pass openstack
end openstack
on startstack
global userchecktime
start using stack HyperCom
tell who
put the result into card field "HyperCom Users
put the seconds into userchecktime
pass startstack
end startstack
on idle
global userchecktime
put (the seconds - userchecktime) into elapsedtime
if (elapsedtime>=15) then
tell who
put the result into card field "HyperCom Users
put the seconds into userchecktime
end if
put the long time into card field "Time
put the long date into card field "Date
pass idle
end idle
CARD BUTTON:
on mouseup
tell whol,,"Set clock of which Mac:
if the first line of the result is empty then exit mouseup
put the result into them
put the seconds into standardtime
tell them, "SetTimeDate", standardtime
end mouseup