[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [MiNT] lp driver patch for the Firebee to extend the parallel port strobe duration





Am 04.10.2015 um 00:59 schrieb Alan Hourihane:
Hi Markus,

Why can't this problem be entirely fixed within the FPGA and not resort
to these additional requirements ?

Alan.


Am 04.10.2015 um 00:59 schrieb Alan Hourihane:
Hi Markus,

Why can't this problem be entirely fixed within the FPGA and not resort
to these additional requirements ?

Alan.


Hi Alan,

sure, the Firebee's high PSG port switching rate could be slowed down to the speed of a Falcon by inserting wait states in hardware in the FPGA config until the 750 ns required by the IEEE 1284 (Centronics) specs are met.

We then had a (fixed) much slower achievable toggle rate (not only for the strobe signal, but probably for the other PSG ports and other possible uses of the parallel port as well).

Just because the software was originally tailored to a specific hardware that only needed two NOPs instead of 21 because it was much slower. The most compatible machine to a Falcon is a Falcon .

Seriously, I don't think that would be the right thing to do.

The Firebee is intended to be as fast as possible and if specific specs for a specific use require it to slow down in places, in my opinion this rather should be done in that part of the software for that specific purpose (printer) instead of generally limit its hardware capabilities.

I'm open for discussion, but that's my feelings.

Cheers,
Markus