gclark@utcsri.UUCP (Graeme Clark) (03/31/87)
When I saw the JTIME build-it-yourself clock article on a local bulletin
board, I was quite interested and almost built it. I didn't, so whether
or not it works I can't say for sure. However if it does work (I expect
it does; the schematic looks reasonable and non-damaging to the Amiga) it
has some problems. For one, the clock-reading software is provided in
binary form only, and is about 20K long (compiled with old Lettuce, I
suppose). In addition, in order to work it will require the DATE and
EXECUTE commands to be present on the boot disk, neither of which I
use since I use the Dillon/Drew shell rather than the CLI. Hence it will
consume about 30K of valuable space on DF0: to use this clock. Another
problem is that the program takes about 5 seconds to read the clock, and
hence adds a 5-second do-nothing pause to each reboot.
The general idea, however, of building a clock that interfaced to the
Amiga via the joystick port was interesting, so I tried to see how
the JTIME design could be improved. Eventually I ended up completely
redesigning it, with the result that I now have a clock which
-- works fine, as far as I know
-- adds only about 1 second to boot time
-- requires only a single program, CLOCK, whose executable is about
7K.
This clock is slightly more complicated than the original (8 chips vs. 6),
but still quite inexpensive.
If people are interested in this design, I will get the schematic in
machine-readable form, write some documentation, and post it.
Graeme Clark -- Dept. of Computer Science, Univ. of Toronto, Canada M5S 1A4
{allegra,cornell,decvax,ihnp4,linus,utzoo}!utcsri!gclark