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The VIC-1211 Super Expander was a cartridge for the Commodore VIC-20 home computer. It was designed to provide several extensions to the BASIC interpreter on the computer, mostly to help with programming graphics and sound. It also provided approximately 3KB of extra RAM. The cartridge was created by Commodore Business Machines (CBM) and released in 1981. In a variety of electronic equipments, a cartridge (in video game terms, cart, game pack, or Game Pak) can be one method of programming different functionality, providing variable content, or a method by which consumables may be replenished. ...
VIC-20 with accessories. ...
The home computer is a consumer-friendly word for the second generation of microcomputers (the technical term that was previously used), entering the market in 1977 and becoming common during the 1980s. ...
BASIC is a family of high-level programming languages. ...
An interpreter is a computer program that executes other programs. ...
Computer graphics (CG) is the field of visual computing, where one utilizes computers both to generate visual images synthetically and to integrate or alter visual and spatial information sampled from the real world. ...
Sound effects or audio effects are artificially created or enhanced sounds, or sound processes used to emphasize artistic or other content of movies, video games, music, or other media. ...
A kilobyte (derived from the SI prefix kilo-) is a unit of information or computer storage equal to either 1024 or 1000 bytes. ...
This article is about the animal, sheep; for other meanings of Sheep, see Sheep (disambiguation). ...
Commodore is the commonly used name for Commodore International, an electronics company who was a major player in the 1980s home computer field. ...
1981 is a common year starting on Thursday of the Gregorian calendar. ...
Description
The dialect of BASIC bundled with the VIC-20, Commodore BASIC V2.0, was notorious for its sparse functionality. It was essentially a straight port from Commodore's older line of microcomputers, the PET. As a result it was outdated by the VIC-20's release and seemed quite primitive compared to BASIC dialects available on other microcomputers. To be fair, the decision by Commodore to recycle the old BASIC, and the fact that it could fit in just 16K ROM (including the Kernal), helped keep the VIC-20's price to a minimum and so contributed to its huge success. Plus it was stable and almost entirely bug-free. Commodore BASIC is the dialect of BASIC used in Commodore Internationals 8-bit home computer line, stretching from the PET of 1977 to the C128 of 1985. ...
In computer science, porting is the adaptation of a piece of software so that it will function in a different computing environment to that for which it was originally written. ...
The PET (Personal Electronic Transactor) was a home-/personal computer produced by Commodore starting in the late 1970s. ...
This article gives an alphabetical List of BASIC dialects—a flat list of variants on the BASIC programming language. ...
Rom is also the name of a toy and comic book character Rom (Spaceknight). ...
The KERNAL is Commodores name for the ROM resident operating system core in its 8-bit home computers; from the original PET of 1977, via the extended, but strongly related, versions used in its successors; the VIC-20, C64, Plus/4, C16, and C128. ...
A computer bug is an error, flaw, mistake, failure, or fault in a computer program that prevents it from working correctly or produces an incorrect result. ...
Nevertheless, not only did "VIC BASIC" lack commands considered fundemental to the BASIC language, such as "else" and "renum", but graphics and sound effects were completely unsupported. To use VIC-20's graphics and sound programmers had to "PEEK and POKE" bytes directly from/to the VIC-20's graphics/sound hardware, the 6560 Video Interface Chip (VIC). This made programming quite tedious and error prone since cryptic memory addresses and codes had to be used constantly, and many statements were required to do even simple tasks. As a result these programs tended to bloat, which in turn blew out efficiency and execution times. Such a thing was death in the tiny RAM and slow interpreted BASIC paradigm of the day. In computing, a command is a directive to a computer program acting as an interpreter of some kind, in order to perform a specific task. ...
Computer graphics (CG) is the field of visual computing, where one utilizes computers both to generate visual images synthetically and to integrate or alter visual and spatial information sampled from the real world. ...
Sound effects or audio effects are artificially created or enhanced sounds, or sound processes used to emphasize artistic or other content of movies, video games, music, or other media. ...
In computing, a programmer is someone who does computer programming and develops computer software. ...
In computing, PEEK is a BASIC programming language function used for reading the contents of a memory cell at a specified address. ...
This article refers to the unit of binary information. ...
Hardware is equipment such as fasteners, keys, locks, hinges, wire, chains, plumbing supplies, tools, utensils, cutlery and machine parts, especially when they are made of metal. ...
The VIC (Video Interface Chip), specifically known as the MOS Technology 6560 (NTSC version) / 6561 (PAL version), is the integrated circuit chip responsible for generating video graphics and sound in the Commodore VIC-20 home computer. ...
Computer programming (often simply programming) is the craft of implementing one or more interrelated abstract algorithms using a particular programming language to produce a concrete computer program. ...
In computer science, a memory address is a unique identifier for a memory location at which a CPU or other device can store a piece of data for later retrieval. ...
A statement is the minimal unit of structuring in imperative programming languages. ...
A computer program (often simply called a program) is an example of computer software that prescribes the actions (computations) that are to be carried out by a computer. ...
An interpreter is a computer program that executes other programs. ...
Programmers could mitigate these problems by using machine code, to an extent, but this in itself was a tedious process. So to address these shortcomings Commodore created the Super Expander cartridge. It provided extra BASIC commands to facilitate using graphics and sound on the VIC-20. It also had commands to read the joystick and lightpen, and to unlocked the use of function keys. A system of codes directly understandable by a computers CPU is termed this CPUs native or machine language. ...
Joystick elements: 1. ...
A lightpen is a device similar to a touch screen, but is facilitated by use of a special light sensitive pen instead of the finger. ...
A function key is a key on a computer or terminal keyboard which can be programmed so as to cause an operating system command interpreter or application program to perform certain actions. ...
Graphics The VIC-20 did not support high resolution graphics directly. Hi-res graphics were implemented by "painting" the display with characters, and "redefining" the character bitmaps on the fly. This was a complex and long-winded process; implementing it in a BASIC program was virtually useless due to the execution time required to draw anything. For the use of the term raster in radio regulation, see frequency raster. ...
The Super Expander took care of all the hard work. It allowed the programmer to draw points, lines, ellipses and arcs, and to paint enclosed regions, with one-line statements. All the VIC-20's 16 colours could be used, although with restrictions due to limitations of the 6560. Display resolution was 160×160 pixels, throttled down from 192×200 allowed by the 6560, probably to minimise the amount of RAM required. Multicolor hi-res was supported (with a resolution of 80×160) and could be mixed with normal hi-res. Graphics and plain text could also be mixed on-screen. The display resolution of a digital television or computer display is the number of pixels (or maximal image resolution) that can be displayed on the screen, usually given as a product of the number of columns (horizontal, X) is always stated first and the number or rows (vertical, Y) make...
A pixel (a portmanteau of picture element) is one of the many tiny dots that make up the representation of a picture in a computers memory. ...
Computer files can be divided into two broad categories: binary and text. ...
Sound The VIC-20's sound capability was uncomplicated, so programming sound effects using "PEEK and POKE" was not so much of a chore as programming graphics. Even so the Super Expander provided a command to play simple tones on the VIC-20's four voice channels, and to control the volume.
Music playback was unsupported on the VIC-20; the usual way of implementing a musical note was to play a tone inside a for loop time delay. In contrast, with Super Expander musical scores could played by simply PRINTing a string of characters. (Music strings were distinguished from regular strings using a special reverse-control-character, familiar to anyone who has used colours or cursor controls in VIC-20 programs.) Each of the VIC-20's four voice channels could play their own scores simultaneously, giving harmonious effects which could be striking by the standards of the time. Computer music is music generated with, or composed with the aid of, computers. ...
In most imperative computer programming languages, a for loop is a control structure which allows code to be executed iteratively. ...
In computer programming and some branches of mathematics , strings are sequences of various simple objects. ...
Harmony is the use and study of pitch simultaneity and chords, actual or implied, in music. ...
Other devices Super Expander provided commands to read the status of the joystick and paddles, and the position of the lightpen. In the case of the joystick, since it was the "digital" or "switch" type, further bit-fiddling was required to decode its position. Joystick elements: 1. ...
A paddle is a game controller with a round wheel and one or more fire buttons, where the wheel is typically used to control movement of the player object along one axis of the video screen. ...
A lightpen is a device similar to a touch screen, but is facilitated by use of a special light sensitive pen instead of the finger. ...
In computer programming, a bitwise operation operates on one or two bit patterns or binary numerals at the level of their individual bits. ...
Function keys Ordinarily the VIC-20's function keys could only be used in a program, by scanning for the appropriate key code when reading the keyboard. In the VIC-20's "immediate" or "calculator" mode they were not available to do anything. With the Super Expander the function keys could be assigned to execute commands in immediate mode. By default they came pre-programmed with the most common BASIC commands, in a similar fashion to the GW-BASIC on the IBM PC. The user could then assign their own commands, or any arbitrary string in fact, to the function keys. A function key is a key on a computer or terminal keyboard which can be programmed so as to cause an operating system command interpreter or application program to perform certain actions. ...
QWERTY computer keyboard A computer keyboard is a peripheral modelled after the typewriter keyboard. ...
GW-BASIC (named after Greg Whitten, an early Microsoft employee and is known more affectionately as gee-whiz) was a dialect of BASIC developed by Microsoft, originally for Compaq. ...
IBM PC (IBM 5150) with keyboard and green screen monochrome monitor (IBM 5151), running MS-DOS 5. ...
Drawbacks - For some reason Commodore designed the Super Expander to map the graphics display to a 1024×1024 coordinate system. Under this scheme, each "virtual" pixel was 6.4 (or 12.8) video pixels in size. This meant that in order to place pixels in exact positions on the screen a further scaling operation had to be coded in.
- The aspect ratio of the output device (i.e. television set) was not taken into account by the coordinate system. So a circle sized, say, 300×300 would appear elliptical. Similarly, a line drawn from (0,0) to (300,300) would not be displayed as 45°.
- When drawing circle arcs, the starting and ending angles had to be specified in "gradians". In this "metric" angular system there are 400 gradians (also called "grads" or "gons") to the circle, as opposed to the familiar 360 degrees. It is a mystery why Commodore chose this obscure and unconventional unit of measure. Perhaps at the time there was a push by academia to supersede the unmetric and homophonous degree with something "better".
- The Super Expander had no capability to put a bitmap to the display. This meant arbitrary bitmaps, as might be used in a hi-res game, had to drawn pixel-by-pixel. The slowness of the BASIC interpreter made this unsuitable for applications like arcade-style games. As a result Super Expander’s usefulness was really hamstrung, consigning it to shape-centric drawings such as charts and simple pictures, or adventure-type games.
- Programs written using the extra Super Expander commands were not portable. A user needed to own the cartridge and have it installed before a program written with the additional commands would run. Loading the program onto an unexpanded VIC-20 gave errors. Therefore the range of software released to take advantage of the Super Expander’s capabilities, including type-in programs published in magazines, was very small. This limited the Super Expander’s appeal and usefulness.
In spite of the above, the Super Expander’s features filled many of the gaps in the VIC-20's programming environment. It must also be remembered that similar microcomputers on the market suffered the same, or equivalent, shortcomings. See Cartesian coordinate system or Coordinates (elementary mathematics) for a more elementary introduction to this topic. ...
The gon is a measurement of plane angles, corresponding to 1/400 of a full circle, thus dividing a right angle in 100. ...
See: International System of Units, colloquially called the Metric System, and also metrication. ...
Degree (angle) - Wikipedia /**/ @import /skins-1. ...
For the use of the term raster in radio regulation, see frequency raster. ...
A computer game is a game composed of a computer-controlled virtual universe that players interact with in order to achieve a defined goal or set of goals. ...
Centipede by Atari is a typical example of a 1980s era arcade game. ...
An adventure game is a type of computer game usually dominated by exploration, puzzle-solving, and interaction with game characters, with the focus on enjoying a narrative rather than testing reflexes. ...
In computer science, porting is the adaptation of a piece of software so that it will function in a different computing environment to that for which it was originally written. ...
Load, in computing, is a measure of the amount of processing a computer system is currently performing, usually in the form of a scalar and as some variation on a percentage. ...
Computer software (or simply software) refers to one or more computer programs and data held in the storage of a computer for some purpose. ...
A type-in program, or just type-in, is a computer program listing printed in a computer magazine or book, meant to be typed in by the reader in order to run the program on a computer. ...
See also Commodore BASIC is the dialect of BASIC used in Commodore Internationals 8-bit home computer line, stretching from the PET of 1977 to the C128 of 1985. ...
The VIC (Video Interface Chip), specifically known as the MOS Technology 6560 (NTSC version) / 6561 (PAL version), is the integrated circuit chip responsible for generating video graphics and sound in the Commodore VIC-20 home computer. ...
External links - ftp.funet.fi: Super Expander manual and demo programs
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