Yah the timer main role is keyboard service 250 time per sec. Plus updating date and time
On Friday, April 23, 2021, Jeffrey Birt <[email protected]> wrote: > Does the RTC drive an interrupt to service the KB? Interesting I did not > realize that. > > > > Jeff Birt > > > > *From:* M100 <[email protected]> *On Behalf Of *Stephen > Adolph > *Sent:* Friday, April 23, 2021 4:56 PM > *To:* [email protected] > *Subject:* Re: [M100] Dead Keyboard > > > > I suspect that there is a problem with the internal real time clock. > > I would check if there is a pulse on pin 10. Hard to verify that I will > admit. > > > > Basically, pin 10 is the timer pulse on the RST7.5 input to the > processor. If you have a problem here your keyboard service routine will > be "dead". > > > > To me it sounds a bit like a dead x1 crystal at pin 12/13 of the real time > clock chil. > > > > On Fri, Apr 23, 2021 at 5:40 PM John R. Hogerhuis <[email protected]> > wrote: > > > > > > On Fri, Apr 23, 2021 at 1:44 PM Matthew Walworth <[email protected]> > wrote: > > Thank you for pointing me at that document, John. No luck with the > procedure fixing the unresponsive keyboard, although it did bring to my > attention that there is a slight glitch in the upper left corner of the > LCD. When first turned on, where it should show "Jan" it shows three other > characters. After being on for a few seconds the "Jan" display appears. I > also just realized that the clock doesn't start counting up after the > reset. It should shouldn't it? > > > > Yes. After a hard reset it should start up in Jan almost immediately (I > think seconds later is significant problem), and the clock should start > counting up. > > -- John. > >
