subroutine has been patched in

 

7. Calls to MID$, LEFT$, RIGHT$, WAIT, PEEK, POKE,

 

TAB, SPC

or ON...GOTO with an improper argument.

ID

Illegal Direct.

You cannot use an INPUT, DEF or GET statement as

 

a direct command.

 

 

LS

Long String.

Attempt was made by use of the concantenation operator

 

to create a string more than 255 characters long.

NF

NEXT without FOR.

The variable in a NEXT statement corresponds

 

to no previously executed FOR statement.

OD

Out of Data.

A READ statement was executed but all of the DATA

 

statements in the program have already been read. The program tried

 

to read too much data or insufficient data was included in the

 

program.

 

 

 

OM

Out of Memory.

Program too large, too many variables, too many

 

FOR loops, too many GOSUB's, too complicated an expression, or

 

any combination of the above. (see Appendix B)

OV

Overflow. The result of a calculation was too large to be represented

 

in BASIC's number format. If an underflow (too small result) occurs,

 

zero is given as the result and execution continues without any error

 

message being printed.

RG

RETURN without GOSUB.

A RETURN statement was encountered

 

without a previous GOSUB statement being executed,

SN

Syntax error.

Missing parenthesis in an expression, illegal character in

 

a line, incorrect punctuation, etc.

ST

String Temporaries.

A string expression was too complex. Break it

 

into two or more shorter expressions.

TM

Type Mismatch.

The left side of an assignment statement was a

 

numeric variable and the right side was a string, or vice versa; or, a

 

function which expected a string argument was given a numeric

 

one or vice versa.

 

UF

Undefined Function.

Reference was made to a user function which

 

has never been defined.

US

Undefined Statement.

An attempt was made to GOTO, GOSUB or

 

THEN to a statement which does not exist.

/0

Division by Zero

 

 

B SPACE HINTS

In order to make your program smaller and save space, the following hints may be useful.

1.Use multiple statements per line. There is a five-byte of overhead associated with each line in the program. Two of these five bytes contain the line number of the line in binary. This means that no matter how many digits you have in your line number (minimum line number is 0, maximum is 63999), it takes the same number of bytes. Putting as many statements as possible on a line will cut down on the number of bytes used by your program.

2.Delete all unnecessary spaces from your program. For instance:

10 PRINT X, Y, Z

uses three more bytes than

10 PRINTX,Y,Z

Note: All spaces between the line number and the first non-blank character are ignored.

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Image 249
Apple II manual Tab, Spc, Space Hints, Printx,Y,Z

II specifications

The Apple II, launched in April 1977, was one of the first highly successful mass-produced microcomputer products. It marked a significant leap in personal computing, setting standards for future developments in the industry. Created by Steve Wozniak and Steve Jobs, the Apple II differentiated itself with its user-friendly design, appealing aesthetics, and robust capabilities.

One of the standout features of the Apple II was its open architecture, which allowed users to expand and enhance the computer's functionality. This design enabled hundreds of third-party hardware and software developers to contribute to its ecosystem, resulting in an array of peripherals, including printers, modems, and storage devices. The Apple II utilized a MOS Technology 6502 microprocessor running at a clock speed of 1 MHz. Initially equipped with 4 KB of RAM, the machine could be expanded to 48 KB, accommodating more complex applications and programs.

The Apple II was also notable for its colorful graphics. It was one of the first computers to support color display, offering a 6-color palette with a resolution of 280x192 pixels in 16 colors when using its Color Graphics Card. This feature significantly enhanced the visual appeal of games and educational software developed for the platform, making computing more accessible and entertaining for various audiences.

Apple's commitment to user experience was evident in the design of the machine. It featured an integrated keyboard and a plastic case, which was both durable and visually appealing. The self-contained design included drive bays for floppy disk drives, allowing for quicker data access than traditional tape drives. It also supported audio output, enabling sound effects and music, a novelty at the time.

The introduction of the Apple DOS operating system further underscored the machine's capabilities. DOS streamlined file management and made it easier for users to navigate and manage their data. The combination of hardware and software positioned the Apple II as an educational tool and a gaming platform, fostering a vibrant software ecosystem.

The Apple II family continued to evolve, with variations like the Apple II+, IIe, and IIgs being introduced over the years. These iterations brought enhancements in memory, processing power, and graphics capabilities. The legacy of the Apple II endures, not only as a foundational product in personal computing but also as a symbol of innovation that paved the way for future advancements in technology. Its impact is still felt today, as it inspired countless developers and shaped the trajectory of the computer industry.