Advance 86
Advance 86 by Advance Technology was manufactured by Ferranti. The Advance 86 was sold either as a home computer, diskless, with Basic in ROM and tape recorder interface called Advance 86a, or as an IBM PC clone with 2x 360 kb 5.25" FDD, 4x 8 bit IBM PC compatible extension slots and 2x 16 bit slots (not compatible with the later ISA slot) called Advance 86b. The 86b was larger (about 3x higher than the 86a or 1.5x higher than an IBM PC) due to the need of an expansion box with room for extension cards, two full  height FDD's and extra power supply. The 86a could be field upgraded to 86b by adding the expansion box on top of the 86a unit and replacing the ROM Basic with a BIOS ROM. The case was black plastic with room for storing the full size IBM compatible keyboard.