The 90-inch cyclotron is a variable-frequency cyclotron operating at from 4 to 10 Mck. The standard neutron time-of-flight electronics are composed of a biased plastic scintillator for a detector, a time-reference signal derived from the cyclotron rf, a time-to-pulse-height converter, a slow amplifier and discriminator, and an Argonne-type 256-channel pulse-height analyzer. Although this basic system is extremely useful, several additions to the system have been found necessary. The replacement of the plastic scintillator with a stilbene crystal and the inclusion of a proton-electron differentiating circuit have reduced unwanted gamma ray background by a factor of 25. To increase the time between bursts of particles, electro-static sweeping is used. The analyzer data can be either printed out or punched on paper tape which is readily converted to punched cards or magnetic tape for computer-processing of data.