Modcomp
| Company type | Private |
|---|---|
| Industry | Computer hardware |
| Founded | 1 January 1970 in Fort Lauderdale, Florida, United States |
| Fate | Renamed to CSPi Technology Solutions |
| Headquarters | Deerfield Beach , United States |
| Products | 16-bit and 32-bit minicomputers (Modcomp III, Modcomp I, Modcomp II, Modcomp IV, Modcomp Classic series) |
Modcomp, Inc., initially known as Modular Computer Systems, specialized in minicomputers tailored for real-time computing tasks. Established in 1970 in Fort Lauderdale, Florida, the firm manufactured 16-bit and 32-bit minicomputers throughout the 1970s and 1980s. Although it held an early position in the market, Modcomp's share declined as microcomputers gained prominence and rivals such as Digital Equipment Corporation introduced their VAX and Alpha lines. Currently, Modcomp operates under the name CSPi Technology Solutions, functioning as a systems integrator based in Deerfield Beach, Florida.
Computers
The company's first offering was the 16-bit Modcomp III, released shortly after its inception. This system included 15 general-purpose registers and initially came with 16 KB of magnetic-core memory, expandable up to 128 KB. For less intensive applications, the smaller Modcomp I featured 3 registers and supported up to 64 KB of core memory. Both models were constructed using SSI and MSI TTL logic components.
In 1972, Modcomp launched the Modcomp II, which preserved compatibility with the III while integrating LSI circuitry. This reflected the company’s ongoing architectural refinement emphasizing modularity—a fundamental aspect of its business approach.
By 1974, the company unveiled the Modcomp IV, a 32-bit system compatible with earlier models and equipped with a paged memory management unit (MMU). Memory capacity ranged from 32 KB to 512 KB with access times between 500 and 800 nanoseconds. It featured 240 general-purpose registers arranged in banks. The MMU facilitated address translation via multiple page tables, supporting efficient real-time operations. The CPU utilized a two-stage pipeline alongside a floating-point unit, enabling it to compete effectively with contemporaries such as the VAX.
Starting in 1978, the Modcomp Classic series succeeded the Modcomp IV beginning with the 7810 model. These systems retained backward compatibility while expanding addressing capabilities to full 32-bit. Subsequent models like the 9250 and 9260 accommodated both 16-bit and 32-bit software, reflecting strategic adjustments to shifting market requirements.
Operating systems
The Modular Applications eXecutive (MAX) series of operating systems was designed for Modcomp hardware. MAX I functioned as a real-time monitor managing fixed processes combined into a single memory image, ideal for numerous embedded applications. MAX II operated as a batch disk OS enhanced with real-time extensions, allowing background program compilation concurrently with real-time foreground execution through fixed-priority preemptive scheduling.
MAX III (for 16-bit machines) and MAX IV (for the Modcomp IV) supported multiple interactive users. MAX III employed a shared address space with swapping to manage several background processes—one per user. MAX IV advanced this by assigning each process its own address space, leveraging hardware features unique to the Modcomp IV. It utilized swapping when physical memory was insufficient and optimized context switching by using all 15 registers. The subsequent MAX 32 was engineered to fully harness the capabilities of the Modcomp Classic series.
Program development
Modcomp provided a Macro-Assembler alongside a Fortran compiler specifically optimized to leverage the hardware's multiple registers for temporary storage of variables and indexes. This compiler streamlined operations involved in mathematical expressions frequently encountered in array indexing and generated Macro-Code that could be assembled into executable machine code. With the introduction of the Modcomp IV, the compiler's output was improved to take advantage of newly introduced hardware instructions, demonstrating a deliberate focus on enhancing software tools to fully utilize system capabilities.
Applications
Initial sales concentrated on monitoring and data acquisition from NASA’s space probes. Throughout the 1980s, Modcomp deployed a network comprising 250 Modcomp II units responsible for managing the Space Shuttle launch complex at Cape Canaveral, as well as the SET at SAIL facility at Johnson Space Center, until control responsibilities shifted to an IBM mainframe. In the 1990s, Modcomp launched ViewMax in the United Kingdom, enabling web-based interfaces to connect with legacy systems. By 1996, prior to its acquisition by CSPI, Modcomp reported revenues totaling $36.7 million.
The Modcomp IV series served as the computational backbone for the PAVE PAWS radar system utilized by the U.S. Air Force Space Command. Beyond aerospace applications, these computers found extensive use in oil industry environments such as refineries and oilfields, as well as in manufacturing automation processes. Prominent clients during the 1970s included Standard Oil and Shell, highlighting Modcomp’s significant presence in industrial control markets.
External links
- Archived version of the company website: modcomp.com.
- Collection of Modcomp II photographs: [1].
- Additional images of Modcomp II systems: [2].
- Levins Technologies, Inc. archive featuring Modcomp Classic Systems photos: [3].