Strange HP-31E Function

[Katie Wasserman]

(10-16-2016 10:26 AM)PANAMATIK Wrote:  

(10-16-2016 01:35 AM)aj04062 Wrote:  Ideas?

This is very likely a ROM bit error, which can result in strange unpredictible behaviour. I own a HP-25C, which couldn't calculate trigonometric functions correctly until I discovered a single errouneous bit in one of its ROM chips.

Bernhard

I agree and I'm pretty sure that the Spice self test does a checksum of the ROM, so it should fail on AJ's 31E.