NEC PC 8001
The PC-8001 was announced by NEC in 1979. The base unit of this modular computer system was a main unit with built-in keyboard and device connectors on the back.
The PC-8001 has an NEC μPD780C-1 (Z80-compatible processor) clocked at 4 MHz, 16 KB of RAM (expandable to 32 KB), CRT video output, cassette port, parallel port for a printer, serial port and an expansion bus. The built-in BASIC interpreter, called N-BASIC, fits in 24 KB of ROM. This is a variant of Microsoft Disk BASIC 4.51. Optional DISK BASIC allows disk I/O for an external floppy drive. The video output is provided by an NEC μPD3301 CRT controller and a μPD8257C (Intel 8257 clone) DMA controller. It has various text modes, and the maximum screen is 80×25 text with 8×8 pixel font. Each character has two attributes chosen from blinking, highlight, reverse, secret, vertical line, over line, under line and RGB colors, and up to 20 different attributes per line can be set. The attribution also supports semi-graphics, and each characters have a 2×4 matrix.
Connectors:
- Centronics printer port
- RS232C serial communications
- IEEE 488
- Cassette Interface, 600 Baud
- Separate Color & BW CRT connectors
The PC-8001 came in a few different models, information about the differences is scarce.
- The PC-8001 - Japanese Market, contains Katakana glyphs in ROM
- The PC-8001 A - US Market, Katakana is replaced with Greek alphabet.
- The PC-8001 BE
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.
RAM max: 64kB
ROM: 24kB
VRAM: 3kB
160x100 graphics
External floppy disk drives
