Sunday, April 18, 2010

The Amiga

The Amiga

I wanted to start with the Amiga - it is a machine that invokes strong emotions in some people, and I have personally owned one (now three.)  The Amiga is a machine of significance not only because of the technology, but also because of the users.  Used by many in the arts, it was the true crossover of technology and computing.  Computers had escaped the businessman's desk and landed in television studios, artist lofts, and in music studios.  Often derided by the business world as a "game machine", the Amiga was misunderstood and sometimes miscast.  Yes, it had many quality games, but also available were "serious" business tools like the Wordperfect word processor (which I used to write papers in college), and professional tools like the Video Toaster system and Lightwave.

There have been many stories told about the birth of the Amiga - it is well documented elsewhere - so I will concentrate on perspective and description.

The core of the Amiga, like the earlier Macintosh, was based on the Motorola  68000 CPU and a 16/32 bit data path to memory and other peripherals.  At the time of release (1987), the 68000 wasn't the top-of-the-line in Motorola's catalog (the 68020 had been available since 1984), but it was a cost effective chip with a growth path.   For perspective, the PC world was a mix of older 8086/8088 machines and the newer "AT" class machines with the Intel 80286 - first deliveries of the 80386 would start in 1987 with limited volume.

Beyond the shared CPU architecture, the Amiga hardware diverged from the Mac quickly, providing custom chips for graphics and sound.  These chips allowed the machine to offload certain operations from the CPU, thus allowing the machine to function at a much higher level than its core processor might indicate.  The Agnus chip, with its blitter and copper functions provided much of the power of the Amiga and contributed greatly to the Amiga's suitability as a graphics machine (and game machine.)

Another hardware trait of the Amiga that contributed to its early success is video support.  At its heart, the Amiga was a video machine. With built-in genlock support  it slotted easily into a video production role.  This was most evident in the display modes available, based on NTSC and PAL standard formats, including true interlaced support.  These formats, combined with the available color modes (most notably HAM), are to my mind the single most important trait of the Amiga, leading to its largest user adoption, but also causing derision from the "business" community.  For video production the Amiga was ideal; for spreadsheets the screen did not have the fidelity that business users demanded - interlaced screens are terrible when you're trying to concentrate on facts and figures.  Later numerous solutions were marketed (and even included as standard in the A3000), known as "flicker fixers" and "scan doublers", but Commodore never really invested in providing a good solution for business users and the Amiga didn't catch up with the Mac and PC worlds until much later with the advent of RTG graphics cards.

Next: AmigaDOS and Intuition

No comments: