Having been dabling in computer graphics for over 20 years, I guess I should start at the beginning.
My first computer was called a UK101. It had a 1MHz 6502, 8K RAM and supported BASIC (when BASIC was BASIC), machine code programming and a tape interface (you had to supply your own tape recorder). This soon got overclocked to 2MHz, then various home-brew cards got built. I made a 16K RAM expansion which doubled up as a "high-res" graphics card. It was great! I also build a character attribute card which allowed blinking, underlined and inverse video characters, rather like teletext. I wrote zillions of "blob chasers" -- tunnel followers, a robotron-like game, dungeon adventures. For the high-res card, a friend and I wrote an asteroids game in 6502 machine code (no assembler then!). We also wrote what must have been the most contorted line drawing routine known to man. It didn't even hit the end points with any reliability (usually resulting in the program being drawn over).
Then came the BBC Microcomputer. A wonder of a machine. Still a 2MHz 6502, but what a difference. The BASIC was fast and powerful, you could write assembler. The graphics were awesome - 8 colours, 8 graphics modes. 32K RAM. Sound! Tape interface again. What more could life hold. And there was software you could buy for it. I have to admit that Defender was one of the reasons for getting the machine. The BBC was powerful enough to start dabbling in animated graphics with (home-grown) sprites and the like. Mathematical function plots were cool (especially if hidden lined). Palette tricks could be used to make things move. We even had a game published "Felix Meets the Evil Weevils" it was called, although the working title was a rather more staid "Larva". My solo creation based loosely on Joust was not so successful, although I still think it was a good game. The BBC grew a liberating floppy drive (100Kbyte) and a sideways RAM card. Ahh those were the days. Its all gone down hill from there on in.
The BBC lasted well, but eventually I succumbed. The Commodore Amiga had a stonking 8MHz (nearly) 68000 processor, and half a megabyte of RAM. Better yet, you could play Marble Madness on it! The graphics were something else. It even had the renowned HAM mode which allowed you to display more colours on the screen than you could shake a stick at. And hand-programmed dynamic HAM was even better (although it killed the machine's performance). It also made one feel superior to Apple machines because it had true multi-tasking. The Amiga was the first platform for a whole host of Ray Tracers. It usually took a night to produce anything decent, but it was worth the wait, just to see grannies amazed face at the "photo-realistic" images. The Amiga eventually grew another half a meg of RAM, then a 20Mbyte hard drive (zowie!) which also boasted another 2MByte of (fast) RAM.
Then one day I borrowed a PC. A lowly 20MHz 386, I think. DOS was awful. The graphics were crummy. The architecture was smelly. But in a straight line it blew the pants off the Amiga. The writing was on the wall. A PC would be the next computer, and so it was. A 90MHz Pentium complete with FDIV bug. I still have the chassis and the monitor, but very little of the original machine remains. Its now a rather nippy 1.4GHz Athlon with 256Mbyte of RAM. Those ray tracing programs that took all night on the Amiga, now run in minutes, and you can get on with word processing at the same time!