The NEC PC-8801 MH is an upgrade over the mkII MR with the only change being an improved CPU. The MH runs on the µPD780008 which is capable of running @8MHz and compatible with the Z80H

Graphics Modes of the NEC PC-8801 MH (see below)
This machine does not support N-mode

• V1 mode
• V2 mode

Kanji Capabilities The machine has a KANJI ROM board, that is capable of displaying the Kanji Characters in 16*16 dots in hi-res mode. The ROM contains character type JIS Level 1 kanji (2965 characters), non-kanji (about 700 types). The screen structure in Kanji mode is 40 characters*20 lines (when using a dedicated high-resolution display).

Features:

• Three expansion slots that are PC-8012, PC8013, PC-8801 and PC-8801MK2 compatible
• 600/1200 baud cassette interface
• General purpose I/O: 4 bits input, 1 bit output, 2 bit input/output
• Parallel printer interface
• RS-232C serial interface with Interrupt/poll option
• Two built-in Floppy Disk Drives (controlled by separate CPU)
• Real time clock with NiCd battery
• FM sound, 3 voices, (49 different tones), 3 voice SSG sound (PSG compatible)
• Line out for sound, built-in speaker
• Digital RGB out (TTL level)
• Analog RGB Out
• Composite video out
• TV Adapter
• 2 screen capability: Text screen and composite video can be independently displayed.

Memory usage:

• Main User's memory: 64KB
• N88-BASIC activation text area: 32KB, variable, work area,
• text VRAM: 31KB
• graphics VRAM: 48KB
• text VRAM: 4KB (only in high-speed mode)
• In-slot expandable memory, available through bank switching n 32KB increments.
• Disk I/O buffer work area: 16KB

The NEC PC-8800 series is a range of home computers manufactured by NEC for the Japanese market between 1981 and 1989. The series began with the launch of the PC-8801 and was marketed as a high-end home computer.

In October of 1982 NEC also launched a 16-bit series of computer, the PC-9800 series. Eventually these computers morphed into NEC branded IBM-PC compatible computers.

The PC-8800 series uses a pair of powerful programming languages: N-BASIC and N88-BASIC. The use of N-BASIC makes the computer compatible with programs written for the NEC PC-8000 series, while N88-BASIC gives the PC-8800 series even more capabilities, especially for graphics. In addition the use of N88-BASIC gives the computer full advantage of memory, to use all of the 64kByte RAM for data and programs.

NEC PC-8800 Sound Capabilities The early computers in the PC-8800 series use a simple internal speaker, much like the Apple II and the IBM PC computers. Later models added FM-synthesis chips for much better music and sound-effects in games.

NEC PC-8800 Graphics modes: Not all modes are available on all machines, see above for the modes available for this machine. The PC-8800 line graphics chip-sets are backwards compatible.

• N mode - PC-8000 series compatible graphics mode
• V1 mode
  • 640(or 320)x200 in 8 colors
  • 640(or 320)x400 in 2 colors
• V2 mode
  • 640x200 in 8 colors out of a 512 color palette
  • 640x400 in 2 colors out of a 512 color palette
• V3 mode
  • 640x200 in 65536 colors
  • 640x400 in 256 out of 65536 colors
  • 320x200 in 65536 colors
  • 320x400 in 64 out of 65536 colors

In V1/V2 400 line mode, the R and B planes are combined to create the greater resolution, at the cost of color depth, only monochrome graphics are available. The G plane is not used for display, and can be used as additional work memory to store data.

List of PC-88 models grouped by their Graphics and Sound capabilities:

The Yamaha YM2203 is an FM Operator Type-N (OPN) chip. It is a six channel sound chip developed by Yamaha. There are 3 FM and 3 SSG channels. The Yamaha OPN family of FM chips is used in many computer systems and video games throughout the 1980s and the 1990s. It was used in later editions of the NEC PC-8800 line of computers, some Sharp computers and many arcade game machines.

The YM2203 generates sound via frequency modulated sine waves. There are 12 different cells that each generate a 13-bit sine wave at a programmable frequency. The volume of each sine wave is controlled by a programmable ADSR envelope generator. The output of these cells can be summed by a mixer, or fed into the input of another cell creating up to 4-cell batches that create the final sound of a channel. Each channel can use 4 cells, for a total of 3 FM channels. Various combinations of ADSR parameters, multipliers and other settings make up the instrument patches, these are FM generated representations of sound that resemble certain intruments.

The SSG module of the YM2203 is basically an implementation of the YM2149 SSG chip, that was included on the YM2203. It has three wave channels and a noise generator.

A YM3014 Digital to Audio Converter (DAC) was used with the YM2203 to generate the audio signal.

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 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 design was licensed to Synertek and Mostek as well as the European SGS.

The Z80s instruction set is binary compatible with the Intel 8080, so that 8080 code such as the CP/M Operating System and Intel's PL/M compiler for the 8080 can run unmodified on the Z80. The Z80 had many enhancements over the 8080 such as 16-bit data movement instructions, block copy and block I/O instructions, single bit addressing of all registers, IX/IY offset registers, better interrupt system and a complete duplicate register file for context switching during an interrupt.