Calendar freeze: Difference between revisions

From NeoGeo Development Wiki
Jump to navigation Jump to search
(Created page with "thumb|Typical freeze screen ([[system ROM|SP-S2) on startup.]] ==Cause== A freeze at startup on the shown screen (with no click of death|cycli...")
(No difference)

Revision as of 04:20, 12 October 2016

Typical freeze screen (SP-S2) on startup.

Cause

A freeze at startup on the shown screen (with no cyclic reset) is caused by the RTC not outputing a time pulse at all.

The system ROM doesn't give a CALENDAR ERROR in this particular case because of a programming oversight.

Suggestions

  • Check battery voltage
  • Check 32768Hz crystal
  • Check uPD4990 traces, especially power and pin 11 (TP)
  • Check NEO-F0 interface pins
Retrieved from "https://wiki.neogeodev.org/index.php?title=Calendar_freeze&oldid=5181"