RPN vs Petal Layout Pro

On January 4, 1972, Hewlett-Packard announced the HP-35, world's first scientific calculator small enough to fit in a pocket - more precisely, Bill Hewlett's shirt-pocket. The HP-35 was an immediate hit with students, engineers, and scientists. Despite its steep price of $395 (about $3000 today), it sold ten times better than anticipated in the first year. Experience this unique calculator that won HP the prestigious "IEEE Milestone in Electrical Engineering and Computing" in 2009. Features: • Photo-realistic look-and-feel • Three skins: version 1, versions 2 & 3 (1973) and final version 4 (1974) • Vintage mode and Enhanced mode • Key-click and key-glow, both optional • Swipe left across display to correct number input errors • Cut/copy/paste display value • Display stack registers and memory registers • All decimal points but one light when iPhone battery charge drops below 5% Vintage mode In this mode, peculiarities of a real HP-35 are simulated: - original speed of operation - stack register Z copied to T on trig functions - leading zeros may be entered; zero can be made negative - a negative number may be entered by pressing CHS before or after the number - a keyboard entry or RCL immediately following STO does not raise the stack - for version 1 only: simulation of a number of known arithmetic bugs Enhanced mode - non-volatile stack and registers - use registers 1 through 9 with HP-45-like register arithmetic - register 0 works as LastX register

Petal Layout is a professional fabrication calculator for developing petal-type layouts for spheres and hemispherical heads. It is designed for pressure vessel fabrication, process equipment manufacturing, spherical tank fabrication, and industrial sheet metal work. The app generates fabrication-ready layout dimensions that can be used for marking plates or sheet metal before cutting, forming, and assembling spherical or hemispherical components. Whether you are a fabrication engineer, fitter, workshop technician, production engineer, or pressure vessel professional, Petal Layout helps simplify complex petal development calculations and improves accuracy during fabrication. Supported Petal Layouts • Hemispherical Head / Hemi Head • Hemispherical Dish End • Sphere / Spherical Tank Hemispherical Head Petal Layout Generate petal development dimensions for hemispherical pressure vessel heads and dish ends. Enter the required head diameter and straight face length, select the desired number of development divisions, and calculate the layout dimensions required for plate marking. Sphere Petal Layout Generate petal-type development dimensions for spherical tanks and spherical shells. Enter the sphere diameter and select the required number of divisions to generate the layout dimensions for fabrication. Development Options Choose from predefined development divisions: • 12 Parts • 24 Parts • 36 Parts • 48 Parts You can also enter a custom number of development divisions according to your fabrication requirements. Features • Sphere petal layout development • Hemispherical head petal development • Dish end petal layout • Spherical tank layout calculations • Multiple development division options • Custom development line/part count • Fabrication-ready marking dimensions • Clear and easy-to-understand results • Simple professional interface • Metric and Imperial unit support • No internet connection required Fabrication Applications Petal Layout is useful for: • Pressure Vessel Fabrication • Spherical Tank Fabrication • Process Equipment Fabrication • Storage Tank Manufacturing • Dish End Fabrication • Hemispherical Head Fabrication • Sheet Metal Fabrication • Industrial Fabrication • Plate Layout and Marking Designed For • Fabrication Engineers • Fabrication Fitters • Production Engineers • Mechanical Engineers • Workshop Technicians • Pressure Vessel Fabricators • Tank Fabricators • Process Equipment Manufacturers • Fabrication Supervisors • Engineering Students For improved fabrication accuracy, the app can be used with appropriate mean dimensions when developing and marking petal layouts. Petal Layout provides a convenient solution for generating sphere and hemispherical head petal development dimensions, helping reduce manual calculations, save fabrication time, and improve accuracy during plate layout and marking.