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- Date: 930626
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- File: set 1200 Baud
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- Finding and Setting Your 1200 Baud
- Rate Factor Value
- ----------------------------------
-
- Having problems uploading files or recieving garbled characters while online in
- 1200 baud!? Likely its your BRF, or Baud Rate Factor...!
-
- As prices of 1200 and 2400 baud modems continue to drop, more and more people
- are now able to experience the thrill of high-speed modeming. One must be
- aware however, that with these faster rates come new problems to contend with.
-
- Commodore's use of software UART, and clock differences between each
- individual computer makes it necessary to 'fine tune' baud rates that are
- faster than 600. A setting which works for you may not work for someone else.
-
- How do you know if your default setting needs adjustment? If you are online
- and you recieve alot of garbled characters in the incoming text, you may need
- to fine tune the 1200 baud rate factor (BRF). The same may be true if you
- encounter numerous errors while uploading or downloading files. (This becomes
- more noticeable while uploading.)
-
- Many terminal programs which support 1200 baud do not provide a means of
- adjusting the BRF and you may be stuck using the default setting as-is.
- Terminal programs that *do* allow you to 'tweek' or 'trim' the BRF (like
- MicroVT-100, Common Sense, and Bobsterm Pro) do not present the option in the
- same way. Therefore, it becomes necessary that you consult your term program
- manual to find out how it is done with your software. In the messages that
- follow this one, we will discuss the commands provided in some of the more
- popular programs.
-
- Regardless of the actual commands used to change the rate, a good way to find
- the best BRF for you is to be online and change the value in small increments
- until garbled characters are no longer jumbled in with the incoming text. Test
- the setting by transferring a file or two. Since uploading is a much more
- sensitive procedure, it would be the better option to try. Adjust the BRF as
- necessary to achieve a setting that gives garble-free text, error-free
- transfers, and best all-around performance for your own individual equipment.
- Once you have determined the optimum setting, you should not need to change it
- again. If your terminal program has an option which allows you to save the
- setting as a default, then by all means do so.
-
- As a note, some of the better terminal programs allow you to change both a high
- byte and low byte value in the baud adjustment options area. When this is the
- case, leave the high byte value set at the default value. It is the coarse
- value used when setting non-standard baud rates and not necessary when trimming
- your 1200 baud. The low byte value is the one you will want to play with, as
- it is a finer control. The reliable range of low-byte settings is between 55
- and 71. For the C-64, you may want to use the low end of that range (57-65)
- and for the C-128 you can start at the high end (68-71).
-
-
- Setting 1200 Baud Rate Factor with BobsTerm Pro:
- -----------------------------------------------
-
- Bobsterm Pro is one of those terminal programs that allow you to change both
- the high byte and low byte in the baud adjust parameters. To get to this
- option area from the main menu of BTPro first hit P for Parameters, and then R
- for RS-232. There you are given a list of adjustable RS-232 parameters. Use
- the cursor to move to the option that says BAUD ADJUST LO BYTE. To change this
- value, simply press RETURN to increment the value and a SHIFT RETURN to
- decrement the value.
-
- Here is Bob Lentini's method of finding the optimum lo-byte setting for 1200
- baud communication using BTPro:
-
- Connect to another system and begin reading a large text file or message base.
- While the data is coming in, go to the parameters and adjust the lo-byte value
- higher by about 5. Then go back and look at the data. If the majority of data
- is garbled, take note of the the setting. Now adjust the lo-byte value lower
- by 5 and check the data. As you go lower the data should begin to clear up.
- Keep adjusting the value lower until the data is mostly garbled again. Take
- note of this setting. Now pick a value midrange between the high and low
- values. This will be the optimum trim for your computer.
-
-
- Setting the 1200 Baud Rate Factor using VT-100:
- ----------------------------------------------
-
- After booting up the VT-100 emulator, all you need to do to get to the modem
- setting options is to press the ALT key and the M key. You will be presented
- with something that looks like the following:
- [1200:H:1S:7W:E:0325]
-
- What you actually see may be different, but we are only concerned with the last
- number shown (0325). This is the default value which VT-100 gives for 1200
- baud, and it is the value we need to change if we are going to fine tune our
- equipment. By pressing the minus (-) or plus (+) keys, you will see the value
- 0325 change appropriately. Refer to the previous two messages concerning how
- to set the correct value.
-
-
-
- Setting the 1200 Baud Rate Factor using Common Sense:
- ----------------------------------------------------
-
-
- To get to the modem setting options in Common Sense, simply press the Commodore
- key (C=) and the M key. You will be shown the modem settings in much the same
- format as those shown for the VT-100 emulator, and in fact, you set the value
- in the same way using plus (+) and minus (-).
-
- Note: the Common Sense method also works for Sixth Sense 64.
-
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