On Mon, Aug 18, 2008 at 09:00:06AM -0700, Bob McGowan wrote: > Tzafrir Cohen wrote: >> On Fri, Aug 15, 2008 at 10:33:50AM -0700, Bob McGowan wrote: >>> Mike Fontenot wrote: >>>> My new PC doesn't have a parallel port on the back (or anywhere else), >>>> and I need one for my HP1200 B/W laser printer. I've seen inexpensive >>>> PCI cards that have one or two parallel ports, and also some cables that >>>> convert between USB and parallel. >> > > --<Deleted on purpose>-- > >>> Speed over USB will be limited to the PP port speed at max but could >>> be impacted by other devices on the USB bus, if there are any. >> >> Speed? Even USB1.1 is about the same speed of a parallel port (probably >> faster). And with USB2 you have nothing to worry about with the speed. >> > > At first reading, I thought you misunderstood my point. On second > reading, I think maybe I misunderstand yours. So, to see if I grok > what you said... > > Since USB 2 can deliver data much faster than the parallel device can > consume it, even if you have multiple devices on a single USB bus, data > will probably get to the printer fast enough for it to receive data at > its highest design rate. > > But, for USB less than 2.0, assuming the USB speed is about equal to the > parallel bus speed, multiple devices could impact data flow enough to > cause the printer to have to wait on occasion. > > According to Wikipedia's IEEE 1284 spec. parallel port speed for EPP/ECP > is 2/2.5 MBits/s, while USB 1.x is 1.5/12 MBits. > > So, unless the USB is constrained for some reason to the 1.5 MBits/s low > speed, USB data rates should be high enough to keep the printer data > transfer rate at it maximum. > > Am I close to understanding correctly?
So you don't have a USB 2.0 port on your system? There's also the strange option of buying a PCI card of a USB controller. Those are quite common and cheap, but then you lose the edge mentioned in: > >>> If it were me, I'd factor in the cost, as well. If they were close, >>> I'd probably choose the USB interface path, mostly due to not >>> needing to open the chassis to implement it. -- Tzafrir Cohen | [EMAIL PROTECTED] | VIM is http://tzafrir.org.il | | a Mutt's [EMAIL PROTECTED] | | best ICQ# 16849754 | | friend -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
