CURSOR #9 – April 1979

“Based on my limited experience with the PET 2040 disk system, I think they screwed it up very effectively...Worst example I can give: you have to write a short BASIC program to find out what error you got when the disk system fouls up.”
—Excerpted from A Cursory Glance, Issue #9

Screenshot of a large spiral pattern composed of PETSCII characters.
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Author: Ken Matthews
Original file name: COVER09
PRG file: cover09.prg

In this month's cover, the PET draws a large PETSCII spiral in alternating regular and inverse video, first from the outside in, and then in reverse. Nothing deep here; just a fun little animated graphic.

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

Screenshot of a Yahtzee scorecard and five PETSCII dice.
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Author: Glen Fisher
Original file name: YAHTZEE
PRG file: yahtzee.prg

YAHTZEE is, not surprisingly, an implementation of the dice game Yahtzee. The main game screen is well designed: the scorecard layout is clean and the PETSCII dice look good. I found the re-rolling input procedure a little counter-intuitive but quickly got used to it. I also had to get used to the reality that the random number generator absolutely hates me. I couldn't roll a single Yahtzee over the course of several games, which I guess makes this version a fairly realistic simulation.

Screenshot of a PETSCII slot machine showing three lemons. Big payout!
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Author: Mark Heaney
Original file name: SLOT!
PRG file: slot.prg

SLOT! is a slot machine game. The machine is drawn quite effectively with PETSCII , although the reels show the names of the fruits rather than interpreting them in graphics characters. The gameplay is simple: place your bet, watch the reels come to rest, and collect your winnings (or go further and further into debt.) You don't have a wallet or tokens; the game will keep track of your score, showing you how far ahead or behind your money total is.

The slot machine is supposed to be completely fair, with no advantage for the house. The author believes that in the long run, you should come out even, but I wouldn't be surprised if there's a slight bias in favour of the player. Because you can go as far into debt as you like, you can essentially play forever without getting kicked out of the casino. I found that if I bet the maximum $5000 on every pull, I'd eventually come out ahead, sometimes by rather a lot of money.

Screenshot of instructions for the PETSCII case-flipping utility.
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Author: Glen Fisher
Original file name: FLIP
PRG file: flip.prg

On the earliest models of the PET, the default display uses the "graphics" character set. If you type any letter, you get an uppercase letter, and if you press SHIFT while typing a letter, you get a PETSCII graphics character. For example, the S key gives you an uppercase 'S', while SHIFT-S gives you a PETSCII heart symbol. There are no lowercase letters available in the graphics mode.

For applications such as word processing, POKE 59468,14 switches the PET to its "business" character set, with both upper- and lowercase letters available for typing. This character set switching comes with an odd quirk: the lowercase letters replace the shifted PETSCII graphics characters, which means that typing that S still gives you an uppercase 'S', but SHIFT-S now gives you a lowercase 's'.

Because this backwards behaviour of the SHIFT key is really cumbersome for touch typists, Commodore decided to revise the character ROM and swap the placement of the upper- and lowercase characters in the business character set. With the newer ROMs, typing feels more natural: unshifted letters are lowercase, and shifted characters are uppercase.

However, this switch sacrifices compatibility: old programs run on newer PETs display text with the cases reversed. aNYBODY WHO USED A pet IN THE 1980S WILL KNOW WHAT i'M TALKING ABOUT. FLIP fixes the case of legacy BASIC programs by going through all strings in PRINT, INPUT, and DATA statements, flipping the case of alphabetic characters to correct the display for modern machines.

Screenshot showing the distance between Toronto, Ontario and Portland, Oregon.
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Author: Martin Mabee
Original file name: CIRCLE
PRG file: circle.prg

The premise of CIRCLE makes it sound way cooler than it actually is. The idea is that you enter two major cities on the globe, and the PET shows you latitude and longitude for both cities and calculates the distance between them. Unfortunately, instead of letting you enter cities directly, the PET has to play some sort of weird guessing game to figure out what you want, and its database of cities is too limited to be useful.

The flyer correctly lists Martin Mabee as the author even though the title page of the program credits Glen Fisher. It's reassuring to know that copypasta errors were a thing even way back in the Dark Ages of personal computers.

Screenshot of a PETSCII backgammon game in progress.
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Author: Glen Fisher
Original file name: GAMMON
PRG file: gammon.prg

GAMMON lets you play backgammon against the PET. The board display makes excellent use of minimalistic PETSCII graphics. The program requires 16K of RAM, so don't expect to run it on the original 8K PET 2001. A significant portion of that 16K is used up by the game's instructions—there are a lot of screenfuls of instructional text.

The gameplay is smooth and not too terribly slow, but I get the feeling that the PET is not very smart. I barely know the rules of backgammon and yet somehow I managed to beat the computer on the first game I played. If only Fisher had implemented the doubling cube...

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