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-
- PACKET89.DOC
- _____________________________________________________________________
- Packet89 is a software interface for use between the Heath Z/H-89 or
- Z/H-90 and a packet TNC. The program may also work on an H-8
- depending upon which I/O board the H-8 has. It is a derivative from the
- MODEM controller called "PLINK".
-
- Three files are used, Packet89.COM, Kernel.COM and Protocol.DTA. The
- first, Packet89, sets the I/O ports for the interface. It allows the
- user to reset the interface BAUD and the word characteristics (size,
- number stop bits, parity, etc.). The default port is the DTE port at
- address 330. If someone else wants a different port he'll have to get
- it through modification of the source code.
-
- The default interface baud is set at 300. On my H-89 this works well
- even though my TNC/transceiver interface is running at 1200 baud. At
- 600 baud, if I try to save to the buffer, an occasional character is
- lost, to buffer, CRT, and printer. At 1200 baud, again, if I try to
- save to buffer, the computer simply can't handle it. If, on the other
- hand, incoming text is not going to buffer, i.e., only to CRT and the
- lineprinter, the computer can handle 1200 baud. This situation was an
- unknown at the time the program was written, being recognized only as
- an attempt was made to run at 1200 baud. Because this program can still
- be used effectively as a telephone modem driver and to permit such use
- I decided to keep the 1200 baud. Another H-89 may function properly at
- 600 baud.
-
- The program allows for use of a control interface protocol between the
- TNC and computer. The user establishes this protocol when the program
- is loaded. In order to transfer a file from disk to TNC, there must be
- agreement between the computer and the TNC. Normally this is achieved
- by selecting "continuous transmit"; that is, no protocol by entering
- "KERNEL U" when requested. Many TNC's will operate in the "X-ON/X-OFF"
- mode. You may want to try it although I've no idea what will be gained.
- It, the "LINE FEED Character" and the "BELL Character" protocols have
- been retained in order to permit the continued use of the program as a
- telephone MODEM controller.
-
-
- USING THE PROGRAM:
-
- Run "Packet89" and respond Y or N when asked if the default protocols
- are acceptable. (They normally should be.) If a change is desired,
- enter "N" and follow instructions. When asked about interface protocol
- select "1" (normally) and enter "KERNEL U" <CR>.
-
- PIE works quite well to prepare a file before transmitting it via packet
- If you choose to do this, however, recall that most BBS's ask for CTL-Z
- at the end of the file. I don't include the CTL-Z in the file but add
- that manually as soon as I see the "FILE TRANSFER COMPLETE" note on the
- CRT. I'm afraid that PIE will strip the 8th bit and mess up the "CTL".
- (Anyhow, by using this technique, I avoid any risk.)
-
- I have included a copy of KERNEL.ASM for the use of anyone who has to
- change the I/O port (or anything else.). There's no reason to muck about
- with PACKET89 so I didn't include the assembly language version. You
- should never have to get involved.
-
- NOTE: If you don't get satisfactory operation of the disk I/O or the
- line printer, check your CONFIGUR.COM. Make sure of the ports and the
- bauds selected for the printer and the TNC. Double check to make sure
- that your TNC and the program default "PARMS" agree (7 bits, 1 stop,
- even parity.) These are easily changed by rerunning PACKET89, setting
- new PARMS, and saving them to disk.
-
- For whatever it's worth, on a SSSD (10 hole) disk I have PACKET89.COM,
- KERNEL.COM, PROTOCOL.DTA, PIE.COM and SWEEP.COM and room for temporary
- storage of files received or to be sent. I find this gives me maximum
- flexibility in all modes and plenty room on the disk. CONFIGUR.COM is
- set to run PACKET89 on cold boot.
-
- I'm making the program available to anyone who requests it via a BBS
- advisory. It should be ideal for MARS or RACES. Feel free to pass it
- along if you want.
- 73s RAY, N6UE
- 73s RAY,