Sharp MZ-821

Sharp MZ-821 – A challenger from Japan

The Sharp MZ-821 is the key model in the MZ-800 series, released in Europe in 1984-85. It was equipped with a built-in cassette recorder, which distinguished it from other models such as the MZ-811 or MZ-831 . It used a Zilog Z80A processor (3,5467 MHz), 64 KB of RAM and 16 KB of video memory, expandable up to 32 KB. The ROM chip of the MZ-821 contains only a simple monitor and boot code – all programs are loaded from a cartridge, Quick-Disk or 5.25″ floppy drive. In basic use, the BASIC interpreter required a download, which took about four minutes for the cassette version – due to slowness, Quick-Disk or floppy disk were the preferred options. The display driver allowed 40/80 column text display, as well as graphic modes: 320×200 and 640×200 pixels in colour (four selectable, up to 16 colours with the VRAM option).

The choice of software was limited mainly to third-party BASIC, Pascal, Forth and Assembler interpreters. There were hardly any comersial games. The MZ-821 was also capable of downloading popular games to the MZ-700, such as Star Avenger, CHOCK-A-Block and LE MANS Turbo. Plug-ins and grammar software were available, developed by the community, but the commercial game and software offerings were modest.

Loading at start-up was slow. The ROM lacked BASIC, which made the machine cumbersome and slow to use. The software offer was limited, especially for commercial games, which reduced the value of the machine. Sharp MZ-821 shield