The Sharp MZ-3500 dual Z80
The Sharp MZ-3500 was released in 1983. Being an 8-bit Z80 based system, it needed to have special features to compete with the 16-bit systems that were already available on the market.
The MZ-3500 series had two Z80 processors each running at 6MHz, and came with 128kB RAM that could be expanded to 256kB. The FDOS and BASIC software that came with it were not upgraded and did not impress. Sharp included a version of CP/M 2.2, but it used a few custom control-codes which caused some incompatibilities. Microtechnology Ltd. came to the rescue; they wrote an alternative version of CP/M 2.2. which uses standard CP/M screen control codes and also includes utilities to allow the user to re-define one or both disk drives for other disk formats. Using these, the MZ-3500 can read CP/M data disks from the Sharp PC-3201 and the Sharp MZ-80B, and some other non-Sharp formats. Unfortunately only the provided CP/M 2.2 can make use of the MZ-3500's color VDU.
The MZ-3500 lacked a reset key and the only way to reset the computer would be to turn it off and back on if software got stuck. Being a Z80-based machine, this computer was not widely sold. As a business computer, it was more or less obsolete when it hit the market.
CPU View - Zilog Z80 Family
The Z80 quickly became popular in the personal computer market, with many early personal computers, such as the TRS-80 and Sinclair ZX80, using the Z80 as their central processing unit (CPU). It was also widely used in home computers, such as the MSX range, SORD, and the Amstrad CPC, as well as in many arcade games. Additionally, it was also used in other applications such as industrial control systems, and embedded systems. The Z80 was widely used until the mid-1980s, when it was gradually replaced by newer microprocessors such as the Intel 80286 and the Motorola 68000.
The Z80 microprocessor was developed by Zilog, a company founded by Federico Faggin in 1974. The Z80 was released in July 1976, as a successor to the Intel 8080. It was designed to be fully compatible with the 8080, but also included new features such as an improved instruction set, more powerful interrupts, and a more sophisticated memory management system.
The Z80 quickly became popular in the personal computer
RAM max: 256kB
VRAM: 16kB
4kB character SRAM
Second CPU has own 8kB RAM Sound Chip none Sound none Display Chip CRT Controller PD7220 Display 600x200 mono Best Text 80x25 Best Color 8 colors in character mode Graphics 600x200 mono Sprites none System OS Monitor System Storage Two built in 3.5" disk drives
or 1 FDD & tape-drive