Camputers Lynx
Camputers Lynx 128
lynx_128

The Camputers Lynx 128, the highest-end model of the Camputers Lynx family produced by Camputers, was released in December 1983.

The Lynx line had appeared earlier that same year with the 48 KB model in March 1983, followed by the 96 KB version around September 1983. The 128 KB machine arrived later as a significantly revised design intended for more serious or business use. The Lynx 128 was later renamed to Laureate

Technically, the Lynx 128 differed from the earlier models in several ways:

  • It used a faster 6 MHz Z80B processor instead of the 4 MHz Z80A used in the 48 KB and 96 KB machines.
  • It had 128 KB of RAM and a new motherboard design.
  • It added an 80-column text mode and was designed to run CP/M 2.2 with optional floppy disk drives.
  • Because of the architectural changes, it was not completely software-compatible with programs written for the earlier Lynx models.

The Lynx 128 appeared only a few months before the company collapsed in June 1984, so relatively few units were produced compared with the earlier models.

The Camputers Lynx had one of the more unusual memory and video architectures among early 1980s home computers. While it used a conventional Zilog Z80 CPU, the way memory and graphics were organized made the machine powerful on paper but awkward to program. The system contained 96 KB of RAM, even though the Z80 could only address 64 KB at a time. To solve this, the Lynx used bank switching, where different portions of RAM could be swapped into the CPU’s address space. However, the video system also needed access to RAM at the same time, so the computer had to constantly switch which memory bank the CPU or video circuitry could see.

The graphics system was tightly tied to this bank-switched memory. Instead of having a separate, dedicated video RAM block like many contemporaries, the Lynx used main RAM for its frame buffer. The video controller—based on the Motorola 6845—read the display directly from system memory while the CPU was also trying to access it. To avoid conflicts, the machine implemented a scheme where the CPU and video hardware alternated access to memory. This effectively slowed down memory access and made graphics operations more complicated than on many competing systems.

Another unusual aspect was the bit-mapped display layout. The Lynx supported a fairly advanced resolution for the time (around 256×248 pixels with up to 8 colours), but pixels were arranged in memory in a non-linear pattern tied to the 6845’s addressing scheme. The colour information was stored in separate memory structures, so plotting a single pixel could require manipulating multiple memory locations and bit masks. As a result, simple graphics operations—such as drawing lines or moving sprites—often required more CPU work than on machines like the Sinclair ZX Spectrum or BBC Micro.

In practice, the architecture gave the Lynx excellent theoretical graphics capability, but the complexity of bank switching and the unusual memory layout meant software developers had to write highly specialized routines to achieve good performance. Because the system arrived late in the UK home-computer market and had a small installed base, relatively few programmers invested the effort required to exploit the hardware fully. This contributed to the machine’s reputation as technically interesting but commercially unsuccessful.

Camputers LYNX-OS

The Camputers Lynx, released in 1983, did not employ a traditional operating system in the sense of disk-based microcomputers. Instead, its software environment was built around a resident monitor and BASIC interpreter stored in ROM. This ROM-based environment provided direct machine-level control, memory management routines, and I/O handling for the keyboard, display, and tape storage. The Lynx’s Z80A CPU operated with a segmented memory map supporting up to 192 KB, divided into 64 KB banks that could be switched in and out, and the firmware contained the fundamental routines for bank switching and peripheral access.

Program execution on the Lynx OS-level environment was mediated through the ROM monitor, which offered hooks into low-level system calls for tape I/O, screen control, and keyboard scanning. Unlike systems with CP/M or MS-DOS, the Lynx’s “OS” was not file-oriented; instead, programs were stored sequentially on cassette tapes, with the ROM providing routines for encoding, decoding, and synchronization. Disk expansion systems were later introduced, and with them came third-party CP/M compatibility layers, but the base machine remained tied to the resident monitor and BASIC environment.

From a system software perspective, the Lynx firmware’s structure emphasized modularity, with jump tables and memory-resident vectors for core routines. This allowed extensions such as disk controllers or third-party ROMs to integrate new functionality by replacing or intercepting existing vectors. The BASIC interpreter itself was tightly coupled to these routines, offering access to graphics, sound, and bank-switched memory directly through language extensions. As a result, the Lynx “OS” can be described as a minimalist, ROM-based firmware environment providing primitive multitasking only in the sense of interrupt-driven device handling, with extensibility dependent on hardware add-ons and patched ROM modules.

Motorola MC6845 Video Display Generator

The Motorola 6845 or MC6845 is a display controller that was widely used in 8-bit computers from the 1980s. The chip was initially designed to coexist alongside the 6800 CPU, but many manufacturers used it in their z80 and MOS6502 architectures as well.

The 6845 has as main function to regulate timing access to display memory, or VRAM. Other circuitry then uses the address generated by the 6845 to fetch the content of the memory and create the image. While the chip was designed for character display, with some programming pixel graphics could also be displayed.

The functionality and design of the 6845 has been a blue-print for later EGA and VGA graphics cards for the IBM-PC compatibles.

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 Great Britain
Brand Camputers UK
Type Camputers Lynx
Name Camputers Lynx 128
CPU Class Z80
CPU Z80B @6MHz
Memory RAM: 128kB
RAM max: 192kB
ROM: 20kB
VRAM: Shared
Sound Chip 6-bit DAC
Sound 6-bit DAC sound capabilities
Display Chip Motorola 6845
Display 256x192 in 16 colors
Best Text 6x10 characters in 256x252 graphics
Best Color 16 colors simultanous
Graphics 256x252 in 8 colors
Sprites none
System OS Lynx OS
Storage Cartridge, Tape, optional 5.25" FDD
Original Price £225
External Links 🌐
Motorola MC6845
Wikipage on the Motorola MC6845 CRTC
Z80 CPU
Wikipedia page on the very popular Z80 8-bit CPU used in many computers of the 1980's era.