Re: [CAD_CAM_EDM_DRO] PCI PARALLEL PORT CARDS FOR DOS CONTROLLER SOFTWARE???????

Peter Reilley wrote:

> There may be a problem with DOS or Win95 and plug-in PCI parallel
> port cards. I suspect that DOS and Win95 will assume that the port is
> at address 0x378 for the primary port and 0x278 for the secondary port.
> No PCI cards can exist at these addresses. The built in parallel port
> is at the standard address.
>
> In those days applications often wrote directly to the parallel port
> addresses
> without using a device driver. Unless the application allows you to enter
> any
> address for the parallel port then you will be out of luck using PCI.
>
> If you need a second parallel port then you are not completely screwed,
> they do still make systems with both PCI and ISA slots. They may be
> a little hard to find but they do exist.

It is actually worse than that. Your OS needs to have PCI
Plug-n-Play enumeration to enable the cards at all. They are in
a kind of dormant state at power on, and the PnP enumeration
code reads the setup info from each PCI card in the system, puts
them into a matrix in memory and then figures out what address
each card should be set to so as to avoid conflicts. If you OS
does not have the PnP enumeration code (DOS, 95 and I think 98
do not) the boards will not function, except in the case of some
old systems that might support this in the BIOS. There might be
an out-board program you can get that does this operation before
the OS boots.

Jon