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- ====================================================
-
- HayesESP driver v0.2 for NFIP 3.3(J)
- Masato Asanuma <asa@comet.sds.co.jp>
-
- ====================================================
-
- This driver is for ESP, which is a Hayes' communication accelarator board.
- By using this driver, you could reach a commmunicating rate above 115.2kbps
- just with serial port, without any byte mistransfering or byte missing or
- anything like that.
-
- This driver really is the one of the best choices for those who are going
- to do some high speed communication on NFIP with an unexpensive TA, which
- is exchangeble between synchronism and unsynchronism and has been provided
- by some venders.
-
-
- * ESP driver:
-
- This driver does not work by itself, it has to be used in the company of
- Mux driver. This is because of the following facts. ESP board is run by
- enhanced mode. But the enhanced is initialized by the driver. And the Mux
- driver carrys out actual serial control.
-
- This driver does not impose any infulence on non-ESP serial port, so the
- standard serial port could be used as well.
-
-
- * Usage with an original serial driver:
-
- Unfortunately, an original serial driver does not work. This is because that
- in 16550 enhaced mode the driver hangs up for some unknown reason and that
- without source code the patch could not be made. In this point of view, it
- is not recommended to use an original serial driver. And some attention should
- be payed to the following fact that with a serial mouse being active, Mux
- driver is not supported.
-
-
- * Patching Mux driver:
-
- In order to make baud rate to a higher rate without losing the 16550
- compatibity, the ESP driver defaultly make baud rate be eight times of
- its set one. So, if baud rate is set to be 14.4kbps, the actual rate will
- be 14.4k * 8 = 115.2kbps. In another words, if you would like to have
- 115.2kbps to commmunicate, you are supposed to set baud rate to be 14.4kbps.
- As for Mux driver it is possible to set baud rate by the above way. In
- case of that this kind of setting is not available with some applications,
- a change should be made with the baud rate in the Mux driver so that the
- 14.4kbps rate could be reached with some setting for baud rate. For example,
- by searching "B2400" in Mux.m file, we could find the following line.
-
- case B2400: speed = 2400; break;
-
- first make a change from speed = 2400 to speed = 14400, that is,
-
- case B2400: speed = 14400; break;
-
- then recompile the source file. After that, the baud rate is 14.4kbps if
- baud rate is set to be 2400bps. Of course this could be done with other
- baud rates.
-
-
- * Installation:
-
- To install the ESP driver, the original serial driver has to be erased first.
- Then install Mux driver and the ESP driver.
- The ESP driver does nor use interrupt and DMA. Port address should be selected
- through setting the jumper on the ESP board and its default is set to be 0x180.
-
-
- * What is the ESP board ?
-
- The ESP has the following charactristics:
- 1. ISA-bus;
- 2. with 16550 enhanced mode;
- 3. DTE rate able to be set up to 921.6kbps;
- 4. with two 1Kbyte buffers, one for transfering, the other for receiving;
- 5. automatic control of HardFlow.
- So it is nice and suitable for high speed communication.
-
-
- * Bundled tools:
-
- There is an utility named chbaud in tool directory. Compile it with make
- command. It is this utility that change the multiplier to baud rate to
- 8 to default. The multiplier should be changed to 1 when baud rate is
- a fixed one in receiving under NXFax or uucp. Even when the multiplier
- is 1, the buffers and auto HardFlow are effective.
-
-
- Usage of chbaud:
-
- This is done by the following commnd.
- chbaud [n]
- where n takes a value from 0, 1, 2, 3.
- when n is omitted, it shows the current multiplier. when n is set, the
- multiplier will be changed accordingly.
- 0 - baud rate x1
- 1 - baud rate x2
- 2 - baud rate x4
- 3 - baud rate x8
- In any cases, this could only be done by a super user.
-
-
- * Cables:
-
- An extanded cable might work and there is nothing wrong with the rate of
- 115.2kbps. But with the rate of 460.8kbps, byte mistransfering happens from
- time to time. Though It is not certain which causes the trouble, TA or cable,
- it might be a good idea using a good cable.
-
-
- * Uncertified things:
-
- There are other two types of ESP board, one with two ports, the another with
- eight ports. If they work or not has not been certified. As for NXFax, the
- same thing can be said, but in most cases, it does not work with a multiplier
- 8 to baud rate.
-
-