This is all I can find for you
What is included in software versions 7.650, 7.660, 7.670, 7.680?
Latest Innovations; Sonar. CHIRP · 360 Imaging ® · Side Imaging ... 958c HD DI, 958c HD XD, 958c HD. 958c DI, 958c XD, 958c. 858c HD DI,
Have you called HB yet?