Re: [PARPORT] ECR setting problem solved, sort of.

Gunther Mayer (
Fri, 11 Feb 2000 11:12:42 +0100

Eugene Weiss wrote:

> Thanks to Michael Eyrich for suggesting that I rmmod the parport and parport_pc
> modules to solve my problem of being unable to change port modes by writing
> to the ecr. It didn't solve the problem, but it gave me enough
> information to find the solution. After I recompiled these as modules, I found
> that the block existed already at bootup, but on launching parport_pc it would
> disappear. Removing parport_pc again had no effect. This gave me enough
> leave to run tests, however, that I found that the block could be removed by
> writing a value of 0x30 to the ecr.

Are you aware of the rules for "Mode Switching" as documented in the
ECP specifications 1.06/ISA Interface standard 1.14 (July, 14 1993) by Microsoft?

If the mode is not 000 or 001 then it can only be switched to 000 or 001.
If in mode 000 or 001 the port may by switched to any other mode.

There are too special rules concerning FIFO status and transfer phase before you
switch some extended mode to 000 or 001.

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