CURSOR #10 – May 1979

“The mail is running about even on the issue of CURSOR publishing 16K programs (such as GAMMON in CURSOR #9). Since some people feel strongly that we should NOT publish large programs, we are going to proceed very carefully. One possibility will be that when we want to publish a 16K program, that we will include it as a sixth program on the tape, so that our loyal 8K subscribers don't feel cheated.”
About Programs Larger than 8K, Issue #10

Screenshot of a set of line graphs representing melodic contours.
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Author: Uncredited
Original file name: COVER10!
PRG file: cover10.prg

This month features CURSOR’s second musical cover. The PET plays six short melodies in a loop while the display draws line graphs tracing the melodic contours of the tunes. "If you have a PET, and you don't have sound," says the flyer, "you are missing one of life's little pleasures."

Pressing SPACE takes you to the table of contents for the issue.

Screenshot of a PETSCII burette set up for a titration procedure.
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Author: Garry Flynn
Original file name: TITRATE
PRG file: titrate.prg

TITRATE is a titration simulation that plays out a bit like a timing game. Use the keyboard controls to mix solutions and get an indicator to change colour. Go too far, and you ruin the sample. The PET will rate your performance, and if you take too long, it will chide you for being slow. A real scientist would probably prefer carry out titrations in a slow, deliberate fashion so as not to waste samples, but then most scientists don't have have to answer to the PET for their performance throughput.

Screenshot of a menu of financial tools: compound interest, mortgage amortization, and pension payouts.
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Author: T. M. Wagner
Original file name: FINANCE
PRG file: finance.prg

FINANCE is a suite of financial calculations: compound interest, mortgage amortization, and pension payouts. I'm not usually a fan of these antique financial calculators, but I could see the mortgage estimator tool being useful in 1979. I put my own mortgage details in as a test and the numbers came out they way I'd expect.

Screenshot of jumble of PETSCII characters with a path traced between opposite corners of the screen.
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Author: Glen Fisher
Original file name: COURSE
PRG file: course.prg

COURSE is a maze game: the PET throws a jumble of random PETSCII box fragments onto the screen and your goal is to manoeuvre around the "obstacles" that result—using the numeric keypad—and find a path from the home position to the bottom right corner of the screen. This one's a fun diversion for a little while but is not deep enough to provide much replay value.

Screenshot of a 'Hello, world!' program written in 6502 assembly language.
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Author: Glen Fisher
Original file name: ASM
PRG file: asm.prg

ASM is a simple symbolic assembler designed to use as little memory as possible. The assembler recognizes the official 6502 opcodes, can handle decimal and hexadecimal values, and allows for user-defined address labels and numeric constants. Not too bad for 8K with some room left over for programming.

The assembly syntax is a little unusual but I get the impression that some of the conventions we are used to today had not yet been standardized. You have to put your assembly instructions into BASIC DATA statements which are then parsed by the program and POKEd into memory. ASM comes with a sample program which you'll need to delete if you want to start writing your own. Deleting these lines is a bit inconvenient; it would have been nice to have been provided with a blank version of ASM.

The flyer comes with three dense pages of instructions, which you'll want to have handy as you get used to the syntax. I found the assembly process to be extraordinarily fussy and managed to crash the machine several times before I finally managed to write a simple ‘Hello, world!’ program in assembly language. I wrote my code on the 4016, so the message will appear as hELLO, WORLD! on the 2001.

Screenshot of instructions for the READER utility.
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Author: Glen Fisher
Original file name: READER
PRG file: reader.prg

READER is a companion program to ASM. If you have a machine language program already in memory, then you can use this utility to generate the DATA statements needed to create a "BASIC loader" program for your code. I ran READER on my ‘Hello, world!’ program and the output looks correct.

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