The Commodore 64
From Maze
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The Commodore 64 was anticipated by a computer of exactly the same physical form, the VIC-20, which was released by Commodore in Japan as the VIC-1001 in 1980. This computer also used the 6502, had the same version of BASIC as did the Commodore 64, but was sold with only 5 KB of RAM, a tiny slice of the Commodore 64's 64 KB. The system also had a display that was 22 characters wide. None of this kept the sytem from running 10 PRINT, of course. The VIC-20 was sold in retail stores (including K-Mart) to a broader market than was reached by previous computers. It was the best-selling computer of 1982 (the year when the Commodore 64 was introduced), selling 800,000 units. But after that, it took a back seat to the more expensive but also much more powerful Commodore 64. The VIC-20 was eventually discontinued -- in 1985. The Commodore 64 was sold through 1994. | The Commodore 64 was anticipated by a computer of exactly the same physical form, the VIC-20, which was released by Commodore in Japan as the VIC-1001 in 1980. This computer also used the 6502, had the same version of BASIC as did the Commodore 64, but was sold with only 5 KB of RAM, a tiny slice of the Commodore 64's 64 KB. The system also had a display that was 22 characters wide. None of this kept the sytem from running 10 PRINT, of course. The VIC-20 was sold in retail stores (including K-Mart) to a broader market than was reached by previous computers. It was the best-selling computer of 1982 (the year when the Commodore 64 was introduced), selling 800,000 units. But after that, it took a back seat to the more expensive but also much more powerful Commodore 64. The VIC-20 was eventually discontinued -- in 1985. The Commodore 64 was sold through 1994. | ||
| − | = Hidden Code = | + | = The KERNAL and the System = |
| − | That BASIC is running on the Commodore 64 specifically introduces even more assumptions. One of these is that the screen will always be 40 characters wide. A few of the unspoken agreements between programmers, BASIC, and the Commodore 64 include: | + | That BASIC is running on the Commodore 64 means that the setup of the machine and its operating system, the KERNAL, must also be considered to see how 10 PRINT will work. One of these assumptions is that the screen will always be 40 characters wide, which is not the case when using the final model of the PET (it has an 80-column display) or the earlier, similarly-shaped VIC-20 (which displayed only 22 characters per line). Aspects of the KERNAL and the system also define these factors: |
<ol> | <ol> | ||
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</ol> | </ol> | ||
| − | In the following discussion, these agreements are made explicit with notation. | + | In the following discussion, the implicit ways in which the system works are made explicit by adding text to 10 PRINT. |
== Truncation == | == Truncation == | ||
