Sorry, I was referring to using a parallel mode in compatibility mode. You can certainly do better with EPP or ECP because the other device has to meet the higher performance standards for them. Bob Ammerman RAm Systems ----- Original Message ----- From: "Kyrre Aalerud" To: Sent: Wednesday, January 22, 2003 1:23 PM Subject: Re: oscilloscope pulse display > Not true Bob. > > I have seen higher frequencies generated by paralell port. > Noone higher than 200 MHz though. By bit-banging 8 bits paralell instead of > doing a normal write you can get 4 mbyte transfer over a paralell link if > you're lucky... > > KreAture > > ----- Original Message ----- > From: "Bob Ammerman" > To: > Sent: Wednesday, January 22, 2003 5:56 PM > Subject: Re: oscilloscope pulse display > > > > Actually it will NOT be all that fast. In order to ensure compatibility > with > > old hardware access to physical ports like the parallel port is slooooowed > > waaaaay dooooown by the chipset. You will typically see signals in the > 1MHz > > range or so. > > > > Also, most parallel ports have rise time control to reduce EMI, and you > have > > to account fro that. > > > > Finally, the same hardware that slows down access to the port introduces > an > > amazing amount of jitter to the signal. So instead of getting a clean > > 1MHzish signal you'll get what almost looks like random edges. > > > > Bob Ammerman > > RAm Systems > > > > ----- Original Message ----- > > From: "Kyrre Aalerud" > > To: > > Sent: Wednesday, January 22, 2003 11:45 AM > > Subject: Re: oscilloscope pulse display > > > > > > > It will be very fast indeed on a 1.1 GHz computer. > > > Depending on what other tasks the computer is doing at the same time, > and > > > depending on how you are switching the pin, it may wery well be at 500 > > MHz. > > > It will also depend on the hardware of the PC. If it can handle what > you > > > are forcing it to do. > > > > > > KreAture > > > > > > > > > ----- Original Message ----- > > > From: "rad0" > > > To: > > > Sent: Wednesday, January 22, 2003 5:27 PM > > > Subject: [ee]: oscilloscope pulse display > > > > > > > > > > OK, you guys talked me into getting an oscilloscope > > > > and now ii's displaying something that is wierd > > > > > > > > I have a program that toggles a pin on the parallel port of a PC > > > > just on then off, as fast as the thing will go > > > > > > > > and this produces a display of a horizontal thick line with > > > > a completely vertical line, spike, every so often, I've forgotten > > > > to record the time between these vertical spikes or lines > > > > > > > > Is it possible that this is just going too fast for the oscilloscope? > a > > > > 100Mhz > > > > the PC is a 1.1 Ghz > > > > > > > > I was expecting a square wave of sorts, and this thing I'm not sure > what > > > it > > > > is... > > > > > > > > > > > > the thing works fine on pic pulses, giving nice square waves for the > > range > > > > of > > > > pulses given by a 20mhz pic > > > > > > > > > > > > > > > > thanks for any insights > > > > > > > > -- > > > > http://www.piclist.com hint: PICList Posts must start with ONE topic: > > > > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > > > > > > > > > -- > > > http://www.piclist.com hint: PICList Posts must start with ONE topic: > > > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > > > > > > -- > > http://www.piclist.com hint: PICList Posts must start with ONE topic: > > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads