!pr0
!lm12
!rm75
Timemaster II from Applied Engineering.....Bob Sander-Cederlof

It may come as a surprise (it did to me), but there are apparently now only three calendar/clocks still on the market for the Apple II, II Plus, //e.  The others, and there were a lot of them, seemed to have dropped off the map.  And even one of the three (Mountain Computer) does not advertise anywhere I can find.

Another surprise:  the most expensive clock has the fewest features, and the least expensive has the most features.


Mountain Computer Apple Clock

!lm+5
$280 in current catalog listing; most recent ad I could find was in Jan 1980 Byte, at $199.  Features below are guessed at from ad and conversations with Dan Pote.  Works with BASIC only, does not include any DOS Dater or ProDOS support.

Gives month, day of month, hour, minute, second, millisecond

Interrupt available:  Second, Millisecond
!lm-5

Thunderware Thunderclock Plus

!lm+5
Gives month, day of month, day of week, hour, minute, second.

$150 with BASIC software for DOS or ProDOS
$ 29 extra for Pascal software
$ 29 extra for DOS-DATER/DEMO disk

Interrupts available:  64, 256, or 2048 times per second
!lm-5

Applied Engineering Timemaster

!lm+5
$129 includes Applesoft support for DOS or ProDOS
     includes Pascal and CP/M support
     includes DOS Dater

Gives year, month, day of month, day of week, hour, minute, second

Interrupts available:  Millisecond, Second, Minute, Hour.  Switchable to either NMI or IRQ interrupt line.
!lm-5


For some reason they have not chosen to explain, the wizards at Apple who created ProDOS decided to "wire in" support for the Thunderclock (and ONLY Thunderclock).  A system call reads the time and date from Thunderclock, calculates the year from the given information, and stores year-month-day-hour-minute in a packed format at $BF90...BF93.  ProDOS automatically records time/date of creation and time/date of last modification.
!np
In order to get the year with these dates, ProDOS goes through a calculation to derive year from given day of month, month, and day of week information.  The calculation involves remaindering and table lookup...but it only works from 1982 through 1987.  I suppose by 1988 they will have generated a new version which works beyond, or else we won't care anymore.  Better yet, by 1988 maybe they will have driver-ized the clock support so we can use Dan's card directly.

Dan Pote sent me a Timemaster to play with, in hopes that I would figure out how to make it look like a Thunderclock to ProDOS.  I did, so if you buy one now it will be completely compatible with ProDOS.  You select by DIP Switch which page of the onboard EPROM will be mapped into the $CN00 space (where N is slot 1-7).  One setting selects the ProDOS section, and the others select various versions designed for use with DOS and Applesoft.

You can talk to Dan's card directly, as well as through the EPROM.  If you don't like the way his firmware works (unlikely), you can either ignore it or change it.

(By the way....  Call A.P.P.L.E., a club/magazine with a penchant for value and quality, has chosen to offer another one of Applied Engineering's boards in its latest catalog:  the Viewmaster 80.  Their price is $140, which is 20% below normal retail.)