The original A 5120 had two
U880 (
Zilog Z80 clone) 8-bit processors, running at 2.25 MHz or 2.5 MHz. One was dedicated to
I/O, while the other was used for normal work. Each was capable of about 625,000 operations per second. It normally came with 16KB of RAM, but a few units shipped with less. When higher-capacity DRAM chips became available, most units shipped with at least 64KB, and some with as much as 112KB. The A 5120.16 upgrade included two new circuit boards, one with a 16-bit U8001 processor (clone of Zilog
Z8000), and the other with 256KB of additional RAM. The original 8-bit system functioned as a terminal to the 16-bit system. For storage, the first A 5120 units had dual magnetic cassette drives, but when the floppy disk version became available, all of these units were converted. The first floppy disk version of the machine included an
8-inch floppy disk drive, with two additional 8-inch drives available in a separate unit. Later, the A 5120 included up to three 5.25-inch drives in place of the 8-inch drive. == Images ==