NEC 6000 Series
PC-6001 A
nec6001a

NEC PC 6001a (USA Model)

When the NEC 6001 was released in the US in 1983, NEC had decided to upgrade the keyboard to a full-stroke typewriter keyboard. The US model was renamed to PC-6001A and was also known as the Nec TREK. Internally the machine is identical to the Japanese version.

The machine had 16K of RAM, and used the uPD780C-1 Z80 compatible CPU running at 4MHz. The graphics were decent at 256x192 pixels in 9 colors. There was an expansion bus on the side of the computer, much like the TI-99's had. NEC sold the PC-6011A expansion unit that allowed the PC-6031 foloppy disk drive to be connected and provided three slots for ROM cartridges.

Pictured here the US version of the NEC 6001, with a full keyboard. Internally the machine is identical to the Japanese version. Also depicted are the Data Recorder and the Expansion Unit, which provides disk drive connectivity and three cartridge slots for ROM cartridges.

Sound - The AY-3-8910 PSG

The AY-3-8910 is a 3-voice Programmable Sound Generator, or PSG. It was designed by General Instruments in 1978 for use with their own 8-bit PIC1650 and their 16-bit CP1610 computers.

The PSG is widely used in many arcade cabinets, pinball machines, and many micro-computers. Here is a list of some of the major brands of computer that used the AY-3-8910:

  • Intellivision
  • Vectrex
  • Amstrad CPC range
  • Oric-1
  • Color Genie
  • Elektor TV Games Computer
  • All MSX-1 and MSX-2 computers
  • ZX Spectrum home computers

General Instrument spun of MicroChip Technology in 1987 and the chip was sold under the MicroChip brand, and licensed to Yamaha as the YM2149F which the Atari ST range of computers use. Functionally the PSG is very similar to the Texas Instruments SN76489.

Variants:

  • AY-3-8910
    Comes with 2 general purpose 8-bit parallel I/O ports, used for Keyboard and Joystick in for instance MSX.
  • AY-3-8912
    Same chip, but in a 28-pin package. Parallel port B is not connected to save cost and space.
  • AY-3-8913
    Same chip, but in a 24-pin package. Both parallel ports are not connected.
  • AY-3-8914
    The AY-3-8914 has the same pinout and is in the same 40-pin package as the AY-3-8910, except the control registers on the chip are shuffled around, and the 'expected input' on the A9 pin may be different. It was used in Mattel's Intellivision console and Aquarius computer.
  • AY-3-8930
    Backwards compatible but BC2 pin is ignored
  • YM2149F
    Yamaha Produced chip, same pin-out as the AY-3-8910, but pin 26 could halve the master clock. Can be used to replace the AY-3-8910 if pin 26 is left disconnected.
  • YM3439-D
    CMOS version of the Y2149 in 40-pin DIP
  • YM3439-F
    CMOS version of the Y2149 in 44-pin QFP
  • YMZ294
    Variant of the YM3249 in an 18-pin package. Parallel ports not connected, and all sound channels mixed on 1 port.
  • T7766A
    Toshiba variant of the AY-3-8910, fully compatible. Used in some MSX models.
  • Winbond WF19054, JFC95101, and File KC89C72: Fully compatible versions of the AY-3-8910 produced for slot machines.

Video - Motorola MC6847 VDG

The MC6847 is a video display generator (VDG) first introduced by Motorola and used in the following machines (this is not a full list):

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.

Technical Details
Released 1983
Country Japan
Brand NEC
Type NEC 6000 Series
Name PC-6001 A
CPU Class Z80
CPU PD780C-1 @4MHz (Z80 compatible)
Memory RAM: 16kB
RAM max: 48kB
Sound Chip AY-3-8910A PSG
Sound 3 Square Wave generators
1 noise generator
16 volume levels.
Display Chip M5C6847P-1 video generator (MC6847 comp)
Display 256x192 mono graphics, 128x192 in 9 colors
Best Color 9 colors
Graphics 256x192 monochrome
Sprites none
System OS N-BASIC
Storage External Tape, External disk drives.
Original Price #349
External Links 🌐
WikiPedia: General Instrument AY-3-8910
Wikipage on the General Instruments AY-3-8910 PSG
Motorola MC6847 VDG
Wikipage on the Motorola MC6847 Video Display Generator
Z80 CPU
Wikipedia page on the very popular Z80 8-bit CPU used in many computers of the 1980's era.