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HP is decreasing the price of the 512K 95LX. The rest of this article looks at the HP 95LX's built-in COMM program and the meaning of various settings. It then shows how to connect two 95LX's via modem.
By HP Palmtop Support
From the FactoryPrice Decrease for 512K 95LX
The retail price for the 512K unit, in the USA as of Sept 1, 1992 is $550. The 1MB 95LX will remain at $799. Some others countries have reduced HP 95LX prices. International users should check with local sales office.
Using The 95LX COMM Program
The HP 95LX user can use built-in COMM with a modem and phone line to communicate with other computers. A COMM user can send (upload) or receive (download) files from a remote computer across the country or even across the world. He can leave electronic mail or even carry on a conversation with a user at the other computer.
The challenge in data communications is to make sure the computers on both ends of the phone line are speaking the same language. That is, both computers (and their modems) must know the speed (baud rate) data is being transmitted, according to what rules (protocol).
To understand the following chart, in COMM press (MENU) Settings Config and you will see the following screen:
The chart lists the parameter in the COMM config screen, followed by an example setting (the setting necessary to log onto CompuServe), followed by an explanation.
this is the only wire serial port on the 95LX.
this assumes your current modem operates at 2400 baud.
1 stop bit is sufficient. 2 stop bits might be used to slow down transmission. The start bit is automatic.
Bit used for error checking. This setting matches that used by CompuServe.
This will provide for the lower 128 chars.
Pulse will also work with touch-tone phones but tone will not work with rotary phones.
This is the phone number.
This is most appropriate for the 95LX on CompuServe.
Readability is enhanced when long lines are wrapped at 40 character increments.
It is a matter of choice whether you want the cursor to delete as it backs up or simply to backspace.
Echo enabled may cause your entries to appear twice on the display (this does not affect communication with CompuServe).
Full duplex provides for simultaneous two-way communication.
Enabling both means of flow control assures the most trouble free data exchange possible on the 95LX.
* Some CompuServe users report these settings better left OFF.
Press (MENU) Settings Save to save settings. Retrieve them with the (MENU) Settings Use command.
SELECTING THE PROTOCOL
When information gets transferred between computers via a modem, both computers must agree on what the data that comes across the phone lines means. All information that gets transferred between computers gets transferred as a series of 1's and 0's. These 1's and 0's make up the content of what is being transferred and the punctuation. The punctuation is necessary so the 1's and 0's can be properly encoded and decoded on each end. The set of rules defining the punctuation is called the "protocol".
The HP 95LX COMM program supports two common protocols supported by many communications packages: XMODEM and KERMIT.
Kermit is one of two protocols built-in to the 95LX to facilitate the transfer of files. Press (MENU) Transfer Kermit Options. You will see only two Kermit Options to configure:
File = binary or text will be chosen depending on the type of file being transferred. (during binary transmission, configure for 8 bit char, no parity)
Block = this is a type of Checksum scheme where you basically can't go wrong.
The Xmodem protocol requires 8 bit characters, no parity in the Settings Config screen. Other settings must match the configuration of the host device. There is no Option menu for Xmodem; Send and Receive are the only choices.
95LX-to-95LX Communication with Modems
For each HP 95LX you need: an HP 82222A Serial interface cable, HP 82224-80003 modem adapter, a modem, access to an analog phone line (not necessary when using acoustic interface).
The simplest communication between two 95LX's gives you effectively the equivalent of two cans connected with a string. The rules for this arrangement are few:
Connect both HP 95LX's to the modem and phone line. On the receiving HP 95LX press (MENU) Connect. Now type ATA (in caps). This puts the receiving HP 95LX in auto answer mode.
On the dialing HP 95LX press (MENU) Connect. Now type in caps: ATDT# where # is the phone number for the receiving unit. After the command to call the other modem is issued, the response on each should be:
caller . . . . . connect 2400
receiver . . . . ring . . . connect 2400
At this point, any keystrokes from either machine will be displayed on the other. With Echo enabled, users will have their keystrokes displayed on their screen also.
To transfer files between 95LX's, the configurations must match each other.
TEXT transfer is the simplest means o*f transferring files. From COMM type (MENU) Transfer Text Options. Char must be set for 8-bit data in this mode. Throttling = 0 and Pacing = None (default) is the simplest configuration to use. Refer to the user's manual for variations to these options.
To send a text (.TXT) file from one 95LX to another, select from the files displayed after pressing the sequence: (MENU) Transfer Text Send. Transmission is virtually instantaneous. The file will appear directly on the screen of the receiving unit. If the file cannot be fully viewed in the screen, use the cursor movement arrows to scroll the display as necessary.
To retain data received by the 95LX in a file, whether it be simple keyboard activity or TEXT transmissions, use the DataComm CAPTURE feature. To initiate a capture from within DataComm, press and hold (CTRL) until the menu appears. Press and release (F5) (Capture) and the display will prompt:
Save incoming data as:
Any existing capture (.CAP) files will also be displayed. Type a file name or select an existing file. The display will return to DataComm and all incoming data will be saved to the file until (CTRL)(F5) is again pressed, closing the file. The DataComm configuration menu provides three options for the Capture feature. The None setting captures all data, refer to the manual for details on Filter and Map.
XMODEM and KERMIT are similarly straightforward. XMODEM has no options, KERMIT has a few. Refer to previous discussion of these two protocols, or the Owner's manual, for specifics.
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