Re: Clock/Calendar Cards For A //e?

[dempson@actrix.gen.nz (David Empson)]

Edhel Iaur, Esq. <drsmooth@relex.com> wrote:

> On 4 Jan 1997 13:58:01 GMT, fl332@cleveland.Freenet.Edu (John L.
> Graham) wrote:
> 
> >I've been using NoSlot Clocks from Alltech Electronics. Only $23.
> 
> Sounds cool...I know it goes under one of the motherboard's chips

Either the CD or EF ROM (check the documentation in case it only works
under one or the other).

> but how does ProDOS recognise it?  Do you need some painful driver
> that limits you to ProDOS v1.0.1, or what?

You need a driver, because the standard ones in ProDOS only support the
ThunderClock (or clones) and the IIgs clock.

I haven't seen the No Slot Clock software for a while, but clock drivers
generally use either of two methods to hook into ProDOS:

(a) The driver is launched during the boot sequence.  It loads itself
into the language card, replacing the old clock driver.

This doesn't require patching any files, and works with any version of
ProDOS (a standard method is used to locate the driver).  The only
complication is having the extra file there.  It must have a name ending
in ".SYSTEM", and must be the first such file.  In general, it will
launch the next ".SYSTEM" file.

(b) The driver is patched into a copy of the PRODOS file.  Booting this
copy of ProDOS will then give you access to the clock.

This method may be dependent on the ProDOS version, since it requires
locating the original driver inside the PRODOS file (which moves around
between versions).  It is also difficult to identify whether a
particular copy of ProDOS includes the driver.
 
-- 
David Empson
dempson@actrix.gen.nz
Snail Mail: P.O. Box 27-103, Wellington, New Zealand