interrupt

QNX Newsgroups (Archives) qdn.public.qnxrtp.devtools
1

I want to connect a switch, on my PC, to generate
an interrupt.

How can I do ?

2

Your question is very general. One way would be to develop
an ISA or PCI card that would do the trick. Another avenue
would be to check out the specification on the Parallel
port. It should be fairly easy to cause the port to cause an
interrupt once it is programmed properly.

Previously, bruno wrote in qdn.public.qnxrtp.devtools:

I want to connect a switch, on my PC, to generate
an interrupt.

How can I do ?

–
Mitchell Schoenbrun --------- maschoen@pobox.com

3

Mitchel hit the nail on the head, do a websearch for “parallel port” and
interrupt. I recently posted some code in comp.so.qnx that sets up the p.port in this way ( it even work in non X86 boards with a p.port)

Previously, Mitchell Schoenbrun wrote in qdn.public.qnxrtp.devtools:
{ Your question is very general. One way would be to develop
{ an ISA or PCI card that would do the trick. Another avenue
{ would be to check out the specification on the Parallel
{ port. It should be fairly easy to cause the port to cause an
{ interrupt once it is programmed properly.
{
{ Previously, bruno wrote in qdn.public.qnxrtp.devtools:
{ > I want to connect a switch, on my PC, to generate
{ > an interrupt.
{ >
{ > How can I do ?
{ >
{
{ –
{ Mitchell Schoenbrun --------- maschoen@pobox.com
{
{
{
{
{

–
Pat Ford email: pford@qnx.com
QNX Software Systems, Ltd. WWW: http://www.qnx.com
(613) 591-0931 (voice) mail: 175 Terence Matthews
(613) 591-3579 (fax) Kanata, Ontario, Canada K2M 1W8

4

Mitchell Schoenbrun wrote:

Your question is very general. One way would be to develop
an ISA or PCI card that would do the trick. Another avenue
would be to check out the specification on the Parallel
port. It should be fairly easy to cause the port to cause an
interrupt once it is programmed properly.

Previously, bruno wrote in qdn.public.qnxrtp.devtools:
I want to connect a switch, on my PC, to generate
an interrupt.

How can I do ?

\

Mitchell Schoenbrun --------- > maschoen@pobox.com

I want use a ISA prototype card to generate an interrupt
, but I don’t know the tehchnologie to use (open collector …)
I looking for a diagram with component to use

5

bruno suarez <bruno.suarez@scola.ac-paris.fr> wrote in message
news:3A772A06.C310D55C@scola.ac-paris.fr…

I want use a ISA prototype card to generate an interrupt
, but I don’t know the tehchnologie to use (open collector …)
I looking for a diagram with component to use

Ha ha, a real live hardware question in a QNX newsgroup!

Your thought of an open collector driver would be normally be a good one,
except that ISA interrupts are rather unusual (and foolish by today’s
standards). To generate an interrupt, you need to provide a rising edge.
You can do this by pulling the irq line low with your open collector driver
until you want to generate the interrupt, at which point you let the line go
high. There is supposed to be a pull-up resistor on the motherboard.
However, experience shows that this does not work on all motherboards, so
real-life implementations of driving an ISA interrupt line simply drive the
line both high and low. If you want to be able to tri-state the interrupt
line to let someone else use it, you can use a tri-statable buffer (like a
74HC125, if memory serves me here).

Hope this helps.

Regards,

Bert Menkveld
Engineer
Corman Technologies Inc.

6

Here is software solution (I know you asked for a H/W solution):

Connect a null modem cable to another computer (serial port to serial
port) and then you can generate an interrupt on the serial port when
ever you send a message (with qtalk or whatever) from the 2nd PC. Then
the enter key on the second computer would generate the interrupt on the
1st.

  • KenR


    bruno wrote:

I want to connect a switch, on my PC, to generate
an interrupt.

How can I do ?