 The card read data from the computer at speeds that demanded the use of SRAM memory, as opposed to lower cost DRAMs.Control signals and setup was sent and received using the S-100 bus's input/output "ports", normally mapped to 0E and 0F.0E contained an 8-bit address pointing to the base of the frame buffer in main memory, while 0F was a bit-mapped control register with various setup information.