Introduction
Sony began selling the SMC-777 personal computer in November 1983. Aimed for the home market, it came with a built-in 3.5-inch floppy disk drive.
The computer was aimed to be used without needing any special knowledge, the SMC-777 could be operated by inserting a floppy disk with the appropriate software program into the computer and selecting the required functions from a screen menu with the cursor keys.
The SMC-777 came with an original disk containing simple programming languages, software, and games to familiarize users with computers and get them interested in programming.
The computer has a Z80A primary, and a M5L8041 secondary CPU. It is capable of 640x200 pixel graphics in 4 colors, and also has a 16 color mode in 320x200 resolution. The machine was upgradable with an optional color palette board, that increased the number of available colors to 16 out of a palette of 4096. Since the SMC-777 was aimed at the Japanese market, it was capable of displaying 2965 JIS Level 1 characters which made the computer into a Japenese-language word processor.
Two joystick ports were provided, and the cursor keys also functioned as a joystick for games. There is one internal slot and a SMC-70 compatible bus for expansion cards.
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.
ROM: 16kB
VRAM: 32kB
320x200 16 color
640x200 4 color graphics.
