On 2015-01-04 12:46, Robert Jarratt wrote:
  When I power up my DECsystem 5100 I get the output
shown at the end of this
 email. I thought this was to do with the DS1287 chip as it seems be an NVRAM
 battery error (perhaps). Since I know these devices fail I took out the
 DS1287, put in a socket and then bought a replacement DS12887A. But I still
 get the same problem. It could be that I bought a bad replacement, or that I
 have done some damage in my desoldering of the original, or it could be that
 the error is something completely different. In fact the Maintenance Manual
 suggests test 9 is to do with the DZ, and I can't find what test 4 relates
 to. 
test 4 is RTC test