Amiga

The Amiga is a family of personal computers sold by Commodore in the 1980s and 1990s. Based on the Motorola 68000 family of microprocessors, the machine has a custom chipset with graphics and sound capabilities that were unprecedented for the price, and a pre-emptive multitasking operating system called AmigaOS. The Amiga provided a significant upgrade from earlier 8-bit home computers, including Commodore's own C64.

The Amiga 1000 was officially released in July 1985, but a series of production problems meant it did not become widely available until early 1986. The best selling model, the Amiga 500, was introduced in 1987 and became one of the leading home computers of the late 1980s and early 1990s with four to six million sold. The A3000, introduced in 1990, started the second generation of Amiga systems, followed by the A500+ and the A600. Finally, as the third generation, the A1200 and the A4000 were released in 1992. The platform became particularly popular for gaming and programming demos. It also found a prominent role in the desktop video, video production, and show control business, leading to affordable video editing systems such as the Video Toaster. The Amiga's native ability to simultaneously play back multiple digital sound samples made it a popular platform for early "tracker" music software. The relatively powerful processor and ability to access several megabytes of memory led to the development of several 3D rendering packages, including LightWave 3D and Aladdin 4D.

Amiga 500

The Amiga 500 - also known as the A500 (or its code name "Rock Lobster") - was the first "low-end" Commodore Amiga 16/32-bit multimedia home/personal computer. It was announced at the winter Consumer Electronics Show in January 1987 - at the same time as the high-end Amiga 2000 - and competed directly against the Atari 520ST. Before Amiga 500 was shipped, Commodore suggested that the list price of the Amiga 500 was US$595.95 without a monitor. At delivery in October 1987, Commodore announced that the Amiga 500 would carry a US$699/£499 list price. In Europe, the Amiga 500 was released in May 1987. In the Netherlands, the A500 was available from April 1987 for a list price of HFL1499.

The Amiga 500 represented a return to Commodore's roots by being sold in the same mass retail outlets as the Commodore 64 - to which it was a spiritual successor - as opposed to the computer-store-only Amiga 1000.

The original Amiga 500 proved to be Commodore’s best-selling Amiga model, enjoying particular success in Europe. Although popular with hobbyists, arguably its most widespread use was as a gaming machine, where its advanced graphics and sound were of significant benefit. Amiga 500 eventually sold 6 million units worldwide.

Mathematical fallacy

In mathematics, certain kinds of mistaken proof are often exhibited, and sometimes collected, as illustrations of a concept of mathematical fallacy. There is a distinction between a simple mistake and a mathematical fallacy in a proof: a mistake in a proof leads to an invalid proof just in the same way, but in the best-known examples of mathematical fallacies, there is some concealment in the presentation of the proof. For example, the reason validity fails may be a division by zero that is hidden by algebraic notation. There is a striking quality of the mathematical fallacy: as typically presented, it leads not only to an absurd result, but does so in a crafty or clever way. Therefore, these fallacies, for pedagogic reasons, usually take the form of spurious proofs of obvious contradictions. Although the proofs are flawed, the errors, usually by design, are comparatively subtle, or designed to show that certain steps are conditional, and should not be applied in the cases that are the exceptions to the rules.