Introduction
The sharp X1 Twin was released in 1982 by the Sharp Corporation. The X1 Twin is really two computers in one: An X1 and a PC-Engine.
The computer comes with two CPU's: The Zilog Z80, running at 3.58MHz for the X1 mode, and the Hudson HuC6280A for the PC-Engine mode. It was an attempt by Sharp to resurrect their market share that they had lost to competitors, mainly the PC8801 from NEC.
The X1 Twin has decent specifications, with 80x25 text mode, and a high resulution of 640x200 in 8 colors. It also has the AY-3-8910 Programmable Sound Generator, capable of 3 channels and white noise, that had become standard in many computers. The X1 Twin came with 64KByte of RAM and 4-48KByte of Video RAM. It had built in Floppy Disk drive, a PC-Engine card slot, and a tape connector
CPU - The Zilog Z80
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.
Originally the Z80 was intended for use in embedded systems, just as the 8080 CPU. But the combination of compatibility, superior performance to other CPUs of the era, and the affordability led to a widespread use in arcade video game systems, and later in home computers such as the Osborne 1, TRS-80, ColecoVision, ZX Spectrum, MSX, Sega's Master System and many more. The Z-80 ran the original Pac-Man arcade cabinet. The Z-80 was used even in the Game Gear (1990s), and the TI-81 and succeeding graphic calculators.
The Z-80 remained in production until June of 2024, 48 years after its original release. Zilog replaced the processor with its successor the eZ80, an 8-bit microprocessor that features expanded memory addressing up to 16 megabytes, and running up to 50MHz, comparable to a Z80 clocked at 150MHz.
VRAM: 48kB
PC-Engine Mode: 256x239 482 colors
