Erik Huelsmann wrote in a message to all:

 EH> What I would like to do, but I dont know how, is to write a
 EH> driver which fakes an lpt4 in my pc. This port could then be
 EH> trapped by FaxWorks, to redirect my output to a fax. (I
 EH> allready have 3 printers to 3 existing lpt-ports connected).

FaxWorks does no device-level communication with the printer.  (The FMD.SYS
driver has to do with the modem, not the printer.)  Rather, FaxWorks hooks
into the system spooler, so all you need to do is create WPS objects for
the new printer and then connect FaxWorks to it.  A neat REXX program to do
this was posted here recently, but it is short enough to repost:

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

/* LPTADD.CMD */

/* Create LPT4-LPT9 printer objects, for network use.
** by Peter McGrath, Fidonet 3:711/957, 95-Aug-15
*/

 call rxfuncadd sysloadfuncs, rexxutil, sysloadfuncs
 call sysloadfuncs

 Do n=4 to 9
  rx=SysIni('SYSTEM', 'PM_SPOOLER_PORT', 'LPT'n, ';'||'00'x)
  If rx\='' Then Say 'LPT'n' Bad result='result
  rx=SysIni('SYSTEM', 'PM_LPT'n,         'DESCRIPTION', 'LPT'||n||'00'x)
  If rx\='' Then Say 'LPT'n' Bad result='result
  rx=SysIni('SYSTEM', 'PM_LPT'n,         'INITIALIZATION', ';'||'00'x)
  If rx\='' Then Say 'LPT'n' Bad result='result
  rx=SysIni('SYSTEM', 'PM_LPT'n,         'PORTDRIVER', 'PARALLEL;'||'00'x)
  If rx\='' Then Say 'LPT'n' Bad result='result
  rx=SysIni('SYSTEM', 'PM_LPT'n,         'TERMINATION', ';'||'00'x)
  If rx\='' Then Say 'LPT'n' Bad result='result
  rx=SysIni('SYSTEM', 'PM_LPT'n,         'TIMEOUT', '45;'||'00'x)
  If rx\='' Then Say 'LPT'n' Bad result='result
 End
Exit

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

 EH> Is it difficult to write such a device-driver? (It should
 EH> mainly trap output, I am not sure it should send it
 EH> somewhere.)

 EH> Can anyone of you tell me how to do this? 

 EH> by the way, I dont have MSC, but I do have TASM and am
 EH> familiar with assembler. (though not with the way OS/2
 EH> handles its memory, things like physical and logical
 EH> address, I don't quite get yet)

Writing an OS/2 device driver is a non-trivial task, and it is not an
especially pleasant experience doing it in pure assembly language.  Since
the OS/2 system spooler is actually an application, not a device driver,
interacting with it does not require another device driver.  In fact, the
whole PM/WPS system is just an OS/2 application, which is why it is
possible to boot OS/2 without PM loaded at all.
 
-- Mike


---