Messages in this thread | | | From | "Ulrich Windl" <> | Date | Wed, 10 Apr 1996 11:33:05 +0100 | Subject | Re: Parallel, IEEE 1284, Zip drive |
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On 9 Apr 96 at 22:07, Grant R. Guenther wrote:
> Albert Cahalan wrote: > > > > > is there already anybody working on a Kernel driver for the new > > > parallel port modes? I'm going to use the EPP mode with a > > > Hardware Project and it would be nice if a device driver > > > were already available! > > > > We have a problem. > > > > PLIP, Zip drives, printers, status bars, ... > > 8/4 bit, 8/8 bit, sometimes 8/8 bit, IEEE this and that... > > > > It seems that the port driver should be apart from the device.
Good idea! I'm thinking of repeated implementations of EPP modes, etc.
> > It is certainly worth thinking about, but I don't know if it will gain us > very much. If all the devices were 1284 compliant, then it would be > possible to design a 1284 API and implement drivers for the different > kinds of physical ports, but PLIP isn't a 1284 device, and from my > work implementing the driver for the ZIP I don't think it is either.
I think "port driver" was not meant to be "parallel SCSI interface"...
> > I tried to compare the ZIP protocol with 1284 - hoping there would > be a correspondence that would validate my reverse engineering effort. > 1284 specifies how one strobes the nybbles in 4-bit mode, for example, > but it doesn't resemble the way the ZIP does it. > > I've also been studying the protocol used by the ShuttleTech chips (as > found in the parallel EZ135, for instance). They use a 16-bit protocol > (in fact, they seem to be doing ISA bus replication), while the ZIP > and PLIP are 8-bit, as are printers. > > There is, however, one thing that *is* desperately needed, and that is > a sharing protocol. The ZIP drive and the EZ135 both support chained > printers. And, if you want to risk your data, you can actually run both > the ppa driver and the lp driver on the same port. (Bill Riemers has been > playing with this and reports that it works - I discourage it because > of the danger that unexpected printing activity would corrupt a disk > data transfer.) > > I recall that someone raised this question a few months ago - Ulrich > Windl, perhaps - but the thread died without any interesting discussion. > (And I was too busy to push it.) > > -------------------------------------------------------------------------- > Grant R. Guenther grant@torque.net > --------------------------------------------------------------------------
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