Subject: Re: How about to config Hayes ESP with glue device rather than magical option?
To: Chris G. Demetriou <>
From: enami tsugutomo <>
List: current-users
Date: 09/11/1997 10:35:23
"Chris G. Demetriou" <> writes:

> We should not have had 'drq2'.  The correct solution to this is to
> allow multiple values for certain locators.

Like `drq 4 and 5' or `port 0x3e0 and 0x280'?  (I just half remember
that I read such mail in past... maybe...).

> > Do you mean that even if the card is operated in ns16x50 compatible
> > mode, it should be the device different from `com'?
> If the card is to be operated in 16x50-compatible mode, it shouldn't
> have any device _other_ than 'com', should it?  If it's to be run in
> "extended" mode, hayesesp should drive it.  If it's to be run in
> compatible mode, 'com' should drive it.

I agree with this.

> Really, both 'com' and 'hayesesp' should probably be front-ends to a
> single back-end driver.  (I don't know how incompatible "extended"
> mode is; i've never seen one of these cards, let alone the docs.)

Probably, should be if the incompatiblity is small and/or is really
`extension'.  But, ...

> What i meant was:
> 	'com' is a front-end for a generic ns16x50 driver.
> If the ESP is "close enough" to a 'com' in extended mode, then
> 'hayesesp' should be a front-end for that same generic back-end
> driver.

... actually, the ESP in extended mode is NOT close to `com'.  But in
compatible mode, the ESP emulates ns16x50 feature at one of standard
com ports, so it is rather close to.  And there is few feature that
ESP provides even in compatible mode but ns16x50 doesn't have.  To use
that feature, we needs to access special port which is one of other
set than standard set of com ports.

With current com driver, the special port is found by probing all
possible four port.  So there is no way to user to restrict them and
the found port is hidden.  This should be fixed, shoudn't it?

Writing `com* at hayesesp0' because of that the ESP emulates ns16x50
is so strange?  Or is just having isa locator `port' with there bad?

Also, I think it is simple if currently merged ESP depended code is
separated from com.c.