I have them On Fri, Jul 4, 2025, 12:57 PM Gregory McGill <[email protected]> wrote:
> Pretty sure I have them now I'll make sure I update stock > > On Fri, Jul 4, 2025, 7:08 AM Stephen Adolph <[email protected]> wrote: > >> >> https://www.arcadeshopper.com/wp/store/#!/Crystal-Oscillator-32-768-KHz-32-768KHZ-32-768K-Hz-Cylinder-3x8mm-quartz/p/237308514 >> >> arcade shopper has the crystals from time to time, or you can get a bag >> of them on ebay pretty easily. >> >> >> >> On Fri, Jul 4, 2025 at 9:57 AM Stephen Adolph <[email protected]> >> wrote: >> >>> https://digilander.libero.it/rar2k/TRS80/Images/M100-Pcb.gif >>> >>> Do you have a scope? You could check that the timer interrupt input >>> RST7.5 is toggling every 4msec. >>> >>> Timer interrupt TP is generated at M18, which is the RTC chip. It is >>> fed from 32.768kHz crystal X1. >>> >>> Not saying for sure this is the problem but it looks similar to other >>> machines I have fixed where that crystal was dead. >>> >>> >>> >>> On Fri, Jul 4, 2025 at 9:06 AM Thomas Morehouse <[email protected]> >>> wrote: >>> >>>> Thanks Steve. Can someone point me to appropriate schematics or >>>> diagrams, finding a replacement crystal, and how to perform the surgery? >>>> TM >>>> >>>> >>>> On Fri, Jul 4, 2025 at 9:01 AM Stephen Adolph <[email protected]> >>>> wrote: >>>> >>>>> it is suffering from excessive interrupt-itis. >>>>> >>>>> On Fri, Jul 4, 2025 at 8:58 AM Stephen Adolph <[email protected]> >>>>> wrote: >>>>> >>>>>> looks to me like the 32768 hz crystal is dead. >>>>>> >>>>>> On Fri, Jul 4, 2025 at 8:56 AM Thomas Morehouse < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> Friday update: >>>>>>> >>>>>>> Batteries replaced with fresh AA alkalines yesterday (Thursday). >>>>>>> Left powered off overnight to recharge backup battery. Powered up this >>>>>>> morning, but no change. See attached screen photo. >>>>>>> >>>>>>> The screen clock seems to be working, but date never changes from >>>>>>> 1/1/1900. >>>>>>> Top four lines of screen appear normal, but below that, definitely >>>>>>> not normal. >>>>>>> >>>>>>> The "center" screen line consists of constantly changing >>>>>>> characters. Lowest screen line appears to be reiterations of "Bytes >>>>>>> free" >>>>>>> - without the "Byt". >>>>>>> >>>>>>> None of the keyboard keys have any effect; when "cursor" is over >>>>>>> BASIC, hitting Enter changes nothing - screen remains unchanged. >>>>>>> >>>>>>> I've done several Cold Starts (CTRL+Pause/Break+Reset) and >>>>>>> (CTRL+Pause/Break+Power switch), but no apparent change. >>>>>>> >>>>>>> Note: when I do a Power On, the screen quickly shows the correct >>>>>>> original default M100 screen, then immediately changes to the garbled >>>>>>> screen. >>>>>>> >>>>>>> Onward through the fog! >>>>>>> Thanks. >>>>>>> Tom M. >>>>>>> >>>>>>
