The primary concern with parallel

Post #102,318 by Steven A S 5/16/03 5:07:51 PM Reply	The primary concern with parallel is that each port is taking (usually sharing with something else) an IRQ. So with two parallel ports, you're using two IRQs. With USB, you're using one IRQ for however many USB devices (up to 127 in theory) are connected. This isn't usually a grave concern though as current computers can share IRQs fairly well (though it's best to avoid sharing with the graphics card). There are adapters out that will allow you to connect parallel printers to USB ports, so if you do decide to move to an all USB setup, you may still be able to use your old trusty printers. Just something to consider. ~~~)-Steven---- "I want you to remember that no bastard ever won a war by dying for his country. He won it by making the other poor dumb bastard die for his country..." General George S. Patton
Post #102,323 by Nightowl 5/16/03 6:29:01 PM Reply	Re: The primary concern with parallel is that each port is taking (usually sharing with something else) an IRQ. So with two parallel ports, you're using two IRQs. With USB, you're using one IRQ for however many USB devices (up to 127 in theory) are connected. Hmmmm what is an IRQ? How many does a computer have? This isn't usually a grave concern though as current computers can share IRQs fairly well (though it's best to avoid sharing with the graphics card). There are adapters out that will allow you to connect parallel printers to USB ports, so if you do decide to move to an all USB setup, you may still be able to use your old trusty printers. Just something to consider. Okay, thanks. I'm sure John knows what they are and what they do. I'll be sure and tell him though :) Nightowl >8# "Only dead fish swim with the stream." Linda Ellerbee
Post #102,327 by Andrew Grygus 5/16/03 7:35:13 PM Reply	Older parallel printers don't use IRQs . . . . . (Standard Parallel Port setting on newer machines) and they can be turned off, or all parallel ports set to IRQ-7 if the IRQ can't be turned off. The driver uses polling to check the printer. Recent enhanced parallel port schemes may actually use an IRQ, I don't know. IRQs used to be very scarce and we were always out of them, but it's not so bad since the PCI bus came along as it can share IRQs among several peripherals and USB has replaced serial ports for many peripherals. [link\|http://www.aaxnet.com\|AAx]
Post #102,340 by Steven A S 5/16/03 10:03:46 PM Reply	IRQs I believe it stands for Interrupt Request. Basically an external device sends a signal to it's IRQ to request that the CPU temporarily interrupt it's current process so that the device can send or recieve information to be processed. There are 16 IRQs; but 4 are used for the internal system, 3 for the normal filesystems (1 floppy, and 2 IDE ports), 2 for the keyboard and mouse (unless using USB devices), 1 or 2 for the sound card, 1 for the graphics card, 1 for each USB root, 1 for each serial port, 1 for each parallel port (though as mentioned they may not be used), etc... ~~~)-Steven---- "I want you to remember that no bastard ever won a war by dying for his country. He won it by making the other poor dumb bastard die for his country..." General George S. Patton
Post #102,367 by Nightowl 5/17/03 1:51:07 AM Reply	Re: IRQs Okay, thanks for explaining that. I forgot to ask John about it tonight, cause I got excited listening to the Ducks Vs Wild game, so I'll ask him tomorrow. Nightowl >8# "Only dead fish swim with the stream." Linda Ellerbee
Post #102,380 by Nightowl 5/17/03 1:12:08 PM Reply	Re: IRQs John says Epstein (The Epson LQ-570+) has a parallel port that uses one IRQ, and Xavier (The Xerox one) also has a parallel port who uses an IRQ. He says we have more than enough IRQs to handle the printers. :) Thanks. Nightowl >8# "Only dead fish swim with the stream." Linda Ellerbee

Welcome to IWETHEY!