Re: Need help on clock card

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

In article <D122I4.FGK@hkuxb.hku.hk>, William <h9104374@hkuxa.hku.hk> wrote:
> 
> 	I come across a clock card label "TIME ][" on the card. There are 
> a 8-bit DIP switch and a variable capacitor on it. Would anyone please 
> tell me some details about this card (eg. how to use it under ProDOS)?

You shouldn't need to use the switches.  Leave then all in the OFF (or
OPEN) position.  They are used to enable periodic interrupts, but you
would need to write special software to take advantage of them.  The
periods available are 1 hour, 1 minute, 1 second and 1024 times per
second, using either the IRQ or NMI signal.

NMI should be avoided at all costs.  An NMI during a floppy disk
access will cause a read error, or destroy part of the disk while
writing.


I have a Time ][ card here, with manual.  Much to my surprise, the
manual claims it is an Applied Engineering card.  I can't see AE
mentioned anywhere on the card itself, so I expect I have a Taiwanese
clone of an AE card, or a VERY old AE card.  The manual covers
installation, accessing the clock registers from BASIC, interrupts,
calibration (involves adjusting the capacitor).

There was no software included with the card, but I seem to recall
writing a ProDOS driver for it at some point.  I'll have to look
through my old source code archives.

It uses an OKI MSM5832 clock chip, which I have used on an old Z80 STD
bus card.  There is no ROM on the card, so it isn't compatible with
the Thunderclock, which is the de-facto standard for Apple II clock
cards, and is the only type of clock which is automatically supported
by ProDOS in a IIe or II+.

(There are several other clocks which emulate the Thunderclock.  The
IIgs's built-in clock doesn't, but ProDOS-8 1.2 and later support the
IIgs clock as well as the Thunderclock.)

To support other clocks, a driver must be installed into ProDOS.  This
can either be done by patching the PRODOS file (not recommended) or by
running a program at boot time which replaces the Thunderclock driver
within the in-memory copy of ProDOS.