wpd@bacchus.UUCP (04/24/87)
In article <1715@cbmvax.cbmvax.cbm.UUCP> eric@cbmvax.UUCP (Eric Cotton) writes: >In article <11335@topaz.RUTGERS.EDU> lachac@topaz.rutgers.edu (Gerard Lachac) writes: >>In article <2300005@hpsadla.HP> jimh@hpsadla.HP (Jim Horn) writes: >>> >>> Does anyone know how the battery-backed real time clock in the Amiga >>>500 and 2000 is addressed? I assume it is used to set the interrupt-driven >>>... and Eric answers... > setclock opt load|save > opt load loads system time/date from clock > opt save saves system time/date to clock >-- > Eric Cotton > Commodore-Amiga However, the original question still remains. How does one physically access that clock? What address must one, to use BASICism's, peek and poke at, in order to set or read the clock? I believe Jim wanted to know so that he could design his own clock to sit at the same address. For you autoconfig buffs, the "correct" way to do this is to use a latch and a comparator. During autoconfig, the Amiga would say, "Who's out there?" And the clock would respond, "I am, but I have no memory", (for just a clock). The Amiga would then say "Fine, your control address is <insert-a-number-here>", which the board would latch onto. Thereafter, whenever ^^^ (that number) was addressed, the comparator would signal true, and the clock would be addressed. (There is more, but I think the idea is understood.) Does the clock in the 500/2000 autoconfig or is it permamently mapped to a certain address and, if so, what address? __________________________________________________ | | | Patrick Doyle (617) 253-3261 (msgs) | | MIT, E40-358 or 225-8467 (home) | | (617) 253-4231 (work) 410 Memorial Dr. | | wpd@athena.mit.edu Cambridge, MA 02139 | | ...{decvax,ihnp4}!mit-eddie!mit-athena!wpd | |________________________________________________|
andy@cbmvax.cbm.UUCP (Andy Finkel) (04/24/87)
In article <473@bacchus.MIT.EDU> wpd@athena.mit.edu (William P Doyle) writes: >What address must one, to use BASICism's, peek and poke at, in >order to set or read the clock? Our clock chip sits at $DC0000. However, unless you use the same clock chip we used (the Okimate clock chip) our program to read/set the clock won't work with your clock design. -- andy finkel {ihnp4|seismo|allegra}!cbmvax!andy Commodore/Amiga /or/ pyramid!amiga!andy } "Do not meddle with the affairs of wizards, for it makes them soggy and hard to light." Any expressed opinions are mine; but feel free to share. I disclaim all responsibilities, all shapes, all sizes, all colors.