On 04/09/2016 04:57 PM, Gene Heskett wrote: > But its sure sounding like one of you two ought to find > 1000 or more chips that you know do work, buy them at > graveyard prices, and build us a board that DOES work. I > believe the parport may be a victim of the "everybody is > useing usb for that stuff now" mentality in the chip > makers board rooms. I've been building stuff using EPP mode since 2001. I have been using almost exactly the same code, and definitely the same sequences of operations on the I/O port registers since then. We did find, along the way, a few parallel port cards and motherboard multi-I/O chips that just got it totally wrong. The NetMos 9805 is pretty famous for advertising DEEP in their datasheet that EPP mode does NOT work.
Up to this point, I have never had a problem with SIIG, but that was all PCI (not express). I have also never had a problem with Dell motherboard parallel ports, except they had a little BIOS quirk, so we have to force the port to EPP mode, even though the BIOS says it is not supported. So, this was a great big surprise, that code that has been working for almost 15 years just doesn't work on these cards! It is all MicroSoft's fault, of course. They wrote the original EPP spec, and it is the loosest piece of electrical specification I've ever seen. Lots of timing diagrams, but not a specification of timing anywhere on them. And, some parport cards actually manage to violate that. So, MicroSoft's document shows the data and WRITE/ lines stabilizing before the strobe, but some boards generate the strobe BEFORE the data lines and WRITE/ are sent! Geez, why write a standard in the first place?? I've found a Syba parport card at NewEgg and Amazon, that is reasonably priced, and clearly does NOT use the Oxford chip. So, I will get one of those to test. Jon ------------------------------------------------------------------------------ Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. It resolves application problems quickly and reduces your MTTR. Get your free trial! http://pubads.g.doubleclick.net/ gampad/clk?id=1444514301&iu=/ca-pub-7940484522588532 _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
