About CGRAPH
CGRAPH originated in 1989 from a small programme originally written for an hp-28c pocket calculator. With the help of this programme, complex calculations could be performed on the small LCD screen of the hp28c – at the time, it served as a (permitted) means of checking answers in a Higher Mathematics III exam for electrical engineering students.
With the leap to a PC-XT class computer (V20 CPU with 12MHz turbo clock frequency), it was then possible for the first time to freely enter functions, even if the necessary sequences still had to be defined manually. The first version of the complex library of mathematical functions still in use today dates from this period. Graphically, one was limited to monochrome Hercules graphics with 720 × 348.
Version 2 of CGRAPH, the first to be commercially available, was released in 1990. It featured the then-standard menu- and window-based interface in text mode, which followed the SAA standard defined by IBM. For the first time, it included a compiler that made it possible to simply enter functions in text form. Although it was now developed on a 386-class computer (386SX with 16 MHz), it was still an application that ran under MS-DOS. Graphics support was expanded; in addition to Hercules, EGA and VGA were now also supported, and of course in colour. The complex graphics functions were now joined by those for real space. Spatial 3D graphics were also possible for the first time. CGRAPH 2 was also available in a special version that supported the mathematical coprocessor, which only became part of the processor with the Intel 486.
CGRAPH 3, released in 1993, was the first Windows version of CGRAPH to hit the market. This version ran in Enhanced 386 mode and, in addition to Windows 3.0, also required a 386-class processor because it made intensive use of extended memory. It was designed as an MDI (Multiple Document Interface) application and was the first to be able to manage multiple graphics simultaneously. Multiple functions were now also possible. A configurable function bar was added, as well as new graphic types such as interpolations and a one-dimensional FFT.
CGRAPH 3.1 was released in the same year. It did not bring any changes in terms of the graphic types offered, but it did make the interface compatible with Windows 3.1, which had become the dominant operating system by then. This version was later also distributed as shareware under the label of the then CTS Ambrosius & Brennecke GbR.
CGRAPH 4 was supposed to mark the transition from a 16-bit version for Windows 3.1 to a 32-bit version for Windows 95 and the then brand-new Windows NT 4 in 1996, but it remained stuck in the experimental stage. The same applies to the attempt to create a version for OS/2, whose user base was already dwindling at the time. However, the CGRAPH 4 interface is already very close to what CGRAPH 5 offers today.
Development of CGRAPH 5 began in 2025. The interface and all functions were completely redesigned. Only the routines for displaying numbers and the compiler survived from the previous versions. All these routines do not use any operating system-specific functions and could therefore be adopted largely without adaptation. Many new functions were also added, such as new types of interpolation and the transformation of entire coordinate systems. The input options were simplified so that the desired results can be achieved quickly and without prior training.
At the same time, computer speeds have increased massively since the first version of CGRAPH was released in 1989. While it took around 6 hours to generate an Mandelbrot set in the first version of CGRAPH on a computer that was state-of-the-art at the time, it can now be drawn in less than a second. In addition, the Firemonkey library now provides a cross-platform framework that has been used to develop the CGRAPH versions for Windows and macOS largely without taking special features into account, meaning that they are functionally identical.