Re: Megahertz problem.

[Jon Bauer <jbauer@cloud9.net>]

> > I've got a kind of strange problem.  Maybe someone can help with the
> > answer.  I have a TP720 (ok, I know it is notthe 720 list, but there is 
> > no 720 list! this will probably apply anyway) 
> 
> Maybe, maybe not.  The 720 is a wierd bird.  For example, it's a
> micro-channel machine (not ISA) and so there are a bunch of d*mn POS
> registers (love that name) that govern whether the devices (including
> the PCMCIA controller) appear on the system bus.  My TP720 tech ref
> manual says that the enable bit in the POS register for PCMCIA is zero
> on power up, meaning that the PCMCIA subsystem is *disabled* by
> default.
That makes sense.

> > and a Megahertz modem.  The 
> > modem works fine if I 1st go into Windows and access Terminal.  I can 
> > then go back to DOS and run a DOS based terminal program or access the 
> > modem.  If I don't access the modem through Windows first, I can't use 
> > the modem.  
> 
> @begin(theory)
> 
> You didn't say what kind of drivers you have installed under DOS, but
> my guess is that of the Windows drivers is turning on the PCMCIA
> system for you.  If so, then it is indeed a TP720 specific problem.
I have all of the PCMCIA socket software loading in the CONFIG, and I run 
the Megahertz setup program to tell the tp that I have the MHZ modem in 
slot 2, and want to set it up as COM2.

> In addition to the POS registers, the PCMCIA subsystem also requires
> its own initialization, say, to map a modem card into the i/o bus as a
> COM2 port.  Again, you might have a Windows driver that will do this
> for you, whereas it wouldn't happen under DOS alone.  Depending on
> what PCMCIA controller chip the TP720 uses (the tech ref manual is
> silent on the subject) this problem might or might not be specific to
> the TP720.
I think that the Megahertz driver should initialize the PCMCIA port.

Here's something that left me scratching my head:  After I run the 
Megahertz DOS executable, I thought I'd try to set-up the port with the 
mode command, so my autoexec looks like this:

@ECHO OFF
PROMPT etc.
MEGAHZ s2c2   (for slot 2, port 2)
MODE COM2:9600,8,n,1
PAUSE

On that mode command, I get an error that says that the port is invalid, 
BUT if I control-c out at this point (note the pause) and then type the 
same command from dos (the mode command) it works perfectly!

The other strange thing, is that I tried using a DOS communication 
program again last night without going into Windows 1st and it worked 
flawlessly.  Maybe I somehow "turned on" the PCMCIA subsystem permanently 
now?

Man, this stuff is flaky.

- Jon