REPORT FROM ISAS 10/26/91 Wow!! Yohkoh has its first X-class flare (10/24/91 @ 2230 UT. The flare flag worked and all instruments acquired good data. The hard x-ray data are superb and the SXT data set is magnificent!!! The flare took place below the big spot umbra in the region that recently rotated onto the disk (darn, I wish there was a quick way to learn the NOAA numbers of active regions). This flare showed several "double" HXR peaks as discussed by Strong et al. and Simnett, et al. SXT observed the flare precursor and right through to well into the decay with excellent exposures, several filters and 2.5 arcsec resolution. There was a white light flare observed with the aspect sensor. [Surprise, the whilte light event does not seem to be causally correlated with the hard x-ray bursts.] We all eagerly await the Hard X-ray images but those do not appear as easity as the SXT pictures. It's late and I'm bushed but what a terrific evening it has been. Loren Acton PS SXT had another Single Event Upset (although this one seems to have been a double) yesterday. This one puzzled us for awhile as it caused the first few lines of the partial frame images to show the effects of inadequate guard band. The usual hard reset and RAM patch fixed everything up as good as new.