Heathkit H-100 Programs in DeSmet C

In addition to the programs on this page, the site has some Borland C programs that were originally in DeSmet and might be converted back to it without too much difficulty. A few of them may have such a comment in their source code, and could be found by searching this site for "DeSmet".

Programs that generate graphics files

Mandelbrot set display

Calculates and displays a region of the Mandelbrot set.

 

Iterated Function Set (IFS) fractal display

Continuously draws fractal shapes based on randomly-generated IFS (Iterated Function System) sets. Has several calculation and display options, including save to disk.

 

Display IFS fractal from disk file data

Reads file data for an IFS (Iterated Function System) set (in either rectangular .IFS or polar .PFS format), calculates and displays the fractal design that it defines.

 

Logistic Map Bifurcation Diagram fractal display

Shows Robert May's bifurcation diagram, as described in Chaos: Making A New Science, by James Gleick.

 

Graphics screen bitmap editor program

A graphics screen (bitmap) editor for the H-100. Uses .PIC format files.

 

Diffusion limited aggregation simulation (DLA)

Simulates diffusion limited aggregation. Particles randomly wander around the screen. When they collide, they stick together.

 

Normal distribution display

Builds a normal distribution at the bottom of the screen, but has the "sticky" routines from DLA.C, so it makes strange treelike formations at the screen bottom, instead, in a vaguely normal distribution.

 

Programs that transform or manipulate graphics files

Each of these simple programs is mostly boring and useless until you need to do the thing that it does.

Dealing with .ZED files

DISPSING.C

Displays a single .ZED file to the H100 screen.

 

ANIMATE.C

Retrieves and displays consecutive ZED files without pausing between them, resulting in an animation.

 

BROWSARC.C

Sequentially extracts ZED files from an ARC file and displays them.

 

ZED2PIC.C

Translates a .ZED format file to .PIC format.

 

Dealing with .PIC files

DISPIC.C

Displays a single .PIC file to the H100 screen.

 

3D.C

Displays a side view of a .PIC file, in an attempt to create a profile view of a Mandelbrot design, with some options of how to display it.

 

ADJUST.C

Adjusts (crops) the dimensions of a .PIC file.

 

INVERPIC.C

Inverts values from a .PIC file. The range 0 -> 255 becomes 255 -> 0, so mountains become valleys and vice versa.

 

SMOOTHE.C

Reduces the jaggedness of a .PIC file by converting its values to n-item moving averages, at least horizontally.

 

UPSIDOWN.C

Rewrites lines from a .PIC file in reverse order to a new file. Line 225 becomes line 1 in the new file, etc., so the image is turned upside down.

 

Miscellaneous Other Programs

Translate Iterated Function Set from rectangular to polar notation

Translates (unreliably) an IFS set from rectangular to polar notation. Has links to other site programs that do it better.

 

Copy one video RAM color plane to another

Merely copies the contents of one color plane into another, demonstrating two methods for setting video memory, using _poke() and _lmove().

 

Statistics calculations

Statistics program reads data from a file, outputs statistics in table format to another file. For one or two variables, calculates n, sum, mean, standard deviation, correlation, slope (m), y-intercept (b), and predicted y for each x. Originally written in DeSmet C, this program listing is in Borland C, but converting it back to DeSmet should be easy.

 

Loan amortization schedule

Computes a loan amortization schedule, showing the payments required to pay off a loan, and for each payment, the amount allocated to principal and the amount allocated to interest.