re:fire and forget was Re: Black box again

Alan,

I am speaking of using the p-port hardware from "user-written"
software which writes the port bits directly (not through dos or
windows). The EPP and even the SPP have "printer" calls which ARE
handshaked, that is why there are pins defined for strobe and ack.

When we use the port for cnc, we usually bypass these routines so
that we CAN "fire and forget". We get to use the strobe and ack lines
for additional I/O as a side benefit.

Hope this helps.

Ballendo

P.S. In this thread originally, "fire and forget" was referring to an
outboard controller. It simply means that the control is asynchronous
(we send commands out when we need to, we get commands back when IT
needs to). We ASSUME that our requests are fulfilled by the
controller (that is the essence of the "forget it" part). If not, the
controller will/may send us an "oops" command or bring a certain pin
hi(or low).

--- In CAD_CAM_EDM_DRO@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> Hi Ballendo,
>
> OK, I get it. But SPP (Standard Parallel Port) doesn't do that for
you,
> at lest for type 1 (IBM). Type 2 or 3 (IBM DMA) might. Aren't you
> thinking of EPP (Enhanced Parallel Port)?
>
> Alan KM6VV