which memory option of PET you are using. It tells you how much memory space is free for you to use. 4k power-on display 8k power - -on display (A byte is the fundamental data element of the PET computer and corresponds roughly to one letter or digit of information. For the curious: the 4k model should show - in theory - ''4096 bytes" and the 8k, "8192 bytes. "But a few hundred are used' by the PET internally. The balance shown "3071 and "7167" are net available bytes.) Figure 1. The keyboard On most typewriters, if you strike a letter key, without shifting, you will get a lower case letter. On your PET, if you press a letter key without shifting, you will get the capital letter.
(See Figure 2.) If you fail to get the power-up display the first time, try turning the power switch slowly off then back on. Rarely will PET fail to respond to this, but if it does. turn to the Hints if You Have a Problem section at the back of this pamphlet. Most noticeable in the display is a flashing white square called a cursor. Whenever PET is waiting for some keyboard information, the cursor will begin blinking and this is where the next charac- ter will appear if it is typed in. Touring the keyboard But, before you can speak to your PET, we need to take a brief tour of the keyboard. Figure 2.
The characters without shifting Each key has a thin, transparent plastic film covering the keytop which should be removed. This protection was left in place to protect the keys against scratches during shipping. To remove the film, carefully peel off with your fingernail. If, on the other hand, you simultaneously press the shift key and a letter key, you will get the particular graphic that appears above the letter: (See Figure 3.) Key top legends bear much resemblance to those of a standard typewriter keyboard, but there are a few differences. The graphics characters are a special set of symbols unique to PET.
They are used to draw pictures and lines on the screen and to perform simple animation. The graphics can be printed on the screen just like any other letter or digit. The letters are all in virtually the same place as on a standard typewriter keyboard, but, for your convenience in numerical computations, the numbers are separate and laid out very much like a calculator keyboard. (See Figure 1.) For now, locate the L key and press it a number of times to get a 2 key. If you did, you'd get L .) I SHIFT 3 row of characters-AAAAA -on the screen. (Do riot use the