Sharing MODEMS

 LBL includes the ability to share remote modems. Unfortunately, not all communication programs permit this. In order to use a remote modem you must use a communication package which supports INT14 redirection. Later versions of PROCOMM do this along with HYPERACCESS, ODYSSEE, and others. Older communication programs and many free or shareware ones probably will not support INT14 redirection or any other redirection capability so they will not work across LBL or any other LAN.

To setup LBL for INT14 redirection support, you must load two device drivers we supply. These drivers are: NETCOM.SYS and NETMSHAR.SYS.

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NETCOM

NETCOM.SYS must be loaded on the computer which has the modem. NETCOM.SYS is a device driver which replaces the BIOS INT 14H handler with an interrupt driven handler more suitable for network redirection. Put NETCOM.SYS in CONFIG.SYS specifying the COM port number and interrupt vector: 
                DEVICE=C:\LBL\UTILS\NETCOM.SYS COM3 INT12
Note: INT12 refers to the CPU vector, not the IRQ, so if using: 
                IRQ:    INT setting:

                Irq2  = INT10
                Irq3  = INT11
                Irq4  = INT12
                Irq5  = INT13
                Irq7  = INT15
                Irq8  = INT112
                Irq9  = INT113
                Irq10 = INT114
                Irq11 = INT115
                Irq12 = INT116
                Irq13 = INT117
                Irq14 = INT118
                Irq15 = INT119
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NETMSHAR

On the computer which does not have the modem you must load the NETMSHAR device driver in CONFIG.SYS: 
                DEVICE=C:\LBL\UTILS\NETMSHAR.SYS  COM3  COM3  ON:17
This example redirects the name "COM3" (the first COM3) to the NETCOM device setup for COM3 (second COM3) on node 17.

Remember to put NETMSHAR above NET00000.

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EXAMPLE setup

CONFIG.SYS, node 17, has the modem on COM3 
  files=20
  buffers=20
  device=\lbl\utils\netcom.sys com3=3E8 int10 /2
  device=\lbl\netunits.sys
  device=\lbl\net00000.sys #17 "mserver"
AUTOEXEC.BAT, node 17 
  \lbl\net8
  \lbl\eth_link
  \lbl\net21
CONFIG.SYS, node 8, has no modem 
  files=20
  buffers=20
  device=\lbl\utils\netmshar.sys com3 com on:17
  device=\lbl\netunits.sys
  device=\lbl\net00000.sys #8 "frontdesk"
AUTOEXEC.BAT, node 8 
  \lbl\net8
  \lbl\eth_link
  \lbl\net21
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TESTING

Setup both nodes as directed above. Then go to the computer with the modem. We include a program called MODEM in the \LBL\UTILS subdirectory which is a simple communications program. For further information on it see the UTILS.DOC file in that subdirectory. But all you should have to do at this point is type: 
                MODEM COM3
assuming NETCOM is set for COM3. Then type: 
                ATZ 

You should see:


                OK



This tells you that the modem got the request and answered it. If you do 
not get the "OK", something is wrong with the NETCOM setup - probably the 
interrupt or baud rate. You can try a different baud rate: 


                MODEM COM3 9600



Once MODEM works on the modem server, try the same thing on the computer 
that doesn't have the modem. If you don't get the "OK" here then NETMSHAR 
is not setup properly.  



Once MODEM works, try your communication package.




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ADVANCED


Other possible NETCOM parameters:



baud:x    default = 5    (which is 2400 baud)
                    0   = 110   baud
                    1   = 150   baud
                    2   = 300   baud
                    3   = 600   baud
                    4   = 1200  baud
                    5   = 2400  baud
                    6   = 4800  baud
                    7   = 9600  baud

parity:0  = no parity
parity:1  = no parity

bits:x,y   x=data bits,  y=stop bits   default = 8,1

/n1,n2,n3  n1=new baud divisor to replace archaic 100 baud
           n1=new baud divisor to replace archaic 150 baud
           n2=new baud divisor to replace archaic 300 baud

This parameter permits you to reassign the obsolete baud rates.
If you wish to use 57600 instead of 100 baud then: /2

ctimes:x  x=number of loops to wait for next char
          default = 50

          This parameter may help avoid overrun errors during high baud 
          rates.  When in an interrupt service routine, we will wait for 
          another character to be received this many tries.  


NOTE: You probably will not need or want to set baud, parity, or bits.  



The most useful parameter in this list is the "/n" parameter.
Our M14_LINK driver uses the 110 baud setting as the default baud
when connecting to remote sites.  Therefore, "/2" sets the default to
56k baud, overriding the terribly slow and useless 110 baud.




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