In 1972, the division decided to move to 4kbit SRAM memory chips in place of core. These were about twice as fast as contemporary low-cost core, and much smaller, allowing 32kword machines to be built in a 2114-like form factor. At the time they made this decision, 4kbit SRAMs were not actually available, so experimental machines using the core from a 2100 series were used initially, replaced by 1kbit SRAM. At first it appeared 4k parts would not be available by the time the rest of the machine had been upgraded, so the company canvassed various manufacturers and found that a few were aggressively developing 4k parts. In particular, Intel, Mostek, Motorola and Texas Instruments were all suggesting such parts would be available in quantity by late 1974.
