CYM1861

The CYM1861 is a high-performance 64-megabit static RAM module organized as 2,048K words by 32 bits. The CYM1861 is constructed from sixteen 1,024K x 4 SRAMs in SOJ packages mounted on an epoxy laminate substrate. Four chip selects are used to independently enable the four bytes. Reading or writing can be executed on individual bytes or any combination of multiple bytes through proper use of selects.

The CYM1861 is designed for use with standard 72-pin SIMM sockets. The pinout is downward compatible with the 64-pin JEDEC SIMM module family (CYM1821, CYM1831, CYM1836, and CYM1841). Thus, a single motherboard design can be used to accommodate memory depth ranging from 16K words (CYM1821) to 2,048K words (CYM1861). The CYM1861 is offered in vertical SIMM configuration and is available with tin-lead edge contacts.

Presence detect pins (PD₀PD₃) are used to identify CYM1861's memory density in applications where modules with alternate word depths can be interchanged.