The Transactor V1 01 1978 New

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( l tcornrnodore

The Transactor

comments and bulletins

concerning your

COMMODORE PET

BULLETIN # 1

Apr.)O,,?8

This i s the f i r s t news bul le t in which wil l be issued up to 12times a year to members of the PET user groups throughoutthe world.

Enclosed i s a form which enables you to join the CanadianPET User Club. Whether you own a PET now or intendpurchasing a PET in the future, or whether at th i s stageyou are not intending to purchase a computer, but are interestedin the developments of personal computers, the followingare some of the benefi ts you wil l get by joining the CPUC:

1. Information on software available

2. Information and specif ications on peripherals f r o ~ Commodore and other people.

3. Information on problem shooting PET bugs and a varietyof other information.

Below i s a free copy of our f i r s t bul le t in .

Now have good

Enclosed is a l i s t of cassette tapes that are now available.We've given br ie f descriptions in each case. And indicatedthe prices .

These programs are only the beginning. From now on,approximately once a month, Commodore will be issuing a II newrelease l l bul le t in . By the year 's end we hope to have l i te ra l lythousands of programs.

Within 30 days, there will be available in one packet what we

consider to be the f inal documentation for the PET. All th iswil l be inc . a t no charge, of course with each PET.

This wil l include:

A revised IIIntroduction to Your PET. 11 An expanded andimproved version of the booklet you've already received.



- 2 -

"PETALK,II a co:npendium of material concerning your PET,including information on in terfaces , the USR function,BASIC in terpre ter and operating system, cassette f i les ,BASIC bugs, the IEEE 488 in terface and available device.

"Sguiggle ll and "Bigtime," two programs on tape completewith an excel lent t ex t booklet tha t te l l s you how theprograms were created, step by s tep. Really, anexcel lent instance of teaching by example.

The Machine Language Monitor. At l a s t . On the other s iof the IISquiggle/Bigtime ii tape also accompanied by anexcel lent text .

While we have your at tent ion, l e t ' s ta lk about peripherals.

The second casset te recorder, a great help in datastorage, will be available soon a t $120.00.* Pleaseallow four to five weeks.

A special impact pr in te r , printing up to charactersper l ine (remember, your PET can accept up to two 40character l ines per statement) on 8W' wide paper, .continuous ro l l or folded. The tentat ive price is$800.* Expected delivery to begin in May.+ We'llsend you t ighter specs and an i l lus t ra t ion next month.

A floppy disc syste:Gl is in the works. I t should beready for announcement in Nay, with delivery scheduledfor late summer. Also about $800.

*Approximate price in Canadian dol la rs .

+USA delivery - Add 2 months fo r CSA approval in Canada •

.. . . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..

To receive future copies of CPUC information bullet ins, pleasEreturn th is form with your cheque fo r $10 annually renei."able,to CEl'1, 3370 Pharmacy Avenue, Agincourt, Ontario, fllW 2K4.

N.A.rlli.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. • .. ".

COMPANY ( i f applicable) • • . • • • • . • • • • • . • . • . • . . • • . • . . . . • • • • • • • • ••

ADDRESS ........................................................................................................... .

.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..

Receipt required Yes 0 No 0(Invoices cannot be issued for the $10 annual fee) .



- :3 -

Welcome to the Canadian PET Users Club and in this issue, wehave some hints on graphics animation, detai ls BASIC

interpreter timings and memory usage, and ASCII codes plusmuch more.

Printed in this and a l l subsequent issues, there wil l be al i s t s o ~ t w a r e available through the Users Club. The originall i s t is small and Commodore Systems generated, but we hope toadd many programmes in the near ~ u t u r e . We intend to ~ o r m a"Common Library" which wil l contain programmes submitted byPET users worldwide and we hope you wil l contribute. Thecontents the Library will be printed in each issue. Anyonein terested in the terms and conditions royal t ies paid byCommodore ~ o r programs accepted by Commodore should write to:

TheS o ~ t w a r e

Manager,Commodore Systems Division,901 C a l i ~ o r n i a Avenue,Palo Alto, C a l i ~ o r n i a 94304,U.S.A.

A SHORT NOTE ON MOVING THINGS

D i ~ ~ i c u l t y has been experienced by some our users in movingthe cursor under programme control and questions have been askedabout how graphs and plots such as sine curves can be displayed.

As you probably already know, cursor control characters in quotes

when printed wil l cause the cursor to move accordingly. yourexperiments so ~ a r with th is technique are giving sl ight ly oddresul ts , do make sure .that you are terminating your prin t s tatement with a semi-colon. Failure to do th is will cause themachine to output a carriage return/line ~ e e d a t the end theprint statement, leaving the cursor jus t where you don't want i t .

On the subject plott ing, the basic t r ick used with this typegraphic system is to f i r s t create s t r ings fu l l cursor

movement characters and then access parts them using MID$, etc.dynamically.

For a really good example the use this technique, I suggest

you have a look a t the technique used in our biorhythm programme.



- 4 .-

BITS AND PIECES

ARE YOU READY?

There have been r ep o r t ed myster ious occurences o f th e o u t o f

da ta e r r o r when e d i t i n g and f i d d l in g about in g en era l .

T h ~ s i s n o t a bug , b u t i s due to press ing RETURN w h i l s t th e

cu rso r i s ove r th e READY prompt. The machine i n t e r p r e t s t h i s

as READ Y and as t h e re i s usua l ly no corresponding data s t a t e

ment around we g e t t h e e r r o r .

REDO

It must be remembered t h a t when RETURN i s p res sed , t h e machine

consumes every th ing on the same l ine as t h e cu r so r , so even if

you have c o r r e c t informat ion a t the beginning o f a given l i n e ,

a s i n g l e ch a rac t e r o f an i n c o r r e c t type fa r over on the r i g h t

hand s id e o f th e sc reen on the same l ine i s l i k e l y to cause

problems. A ra the r problemat ica l example o f t h i s s i t u a t i o n

occurs if you t ry and pu t up a graphic form o r s e t o f boxes

on the sc reen and then under programme co n t ro l ask fo r data

with an i npu t s t a t ement , e . g .

NUMBER ?

When the number i s typed and RETURN i s pressed , the graphics

ch a rac t e r making up the r igh t -hand s ide o f the box w i l l be

en te red as p a r t of the i npu t t ing da ta . In the case of inpu t

to a numeric v a r i ab l e , the graphics charac te r i s o f course

non-numeric and no t al lowed a.nd w i l l give the e r r o r ? Redo

from s t a r t , so you must always l eave such boxes open ended.



- 5 -

INVERSE TRIGNOMETRIC F U N C T I O ~

Here are a couple of handy methods of obtaining are sine and arc

cosine (remember, the resu l t wi l l be in radians) .

ASNX = ATN (X/SQR(l-xt2)

ACSX = ATN (SQR(l-Xt2)/X)

For those of you who are used to working in degrees, here are some

handy user defined functions:

DEFFNS(V) = S I N ( V / ( l 8 0 / ~ » DEFFNC(V) = C O S ( V / ( l 8 0 / ~ » DEFFNT{V) = T A N ( V / ( l 8 0 / ~ » These are three user defined functions which when cal led with

arguments and degrees wil l give the appropriate resu l t s . In these

examples V can be any variable but i f a l l three are defined in

the same programme, you must use three different dummy variables .

EXAMPLE: PRINT FNS ( 30)

Result of th i s wi l l be .5 . Notice tha t the argument for FNS, or

FN anything for tha t matter, can be e i the r a variable or numeric

constant . Also, af te r a programme containing these defini t ions

has been run, these functions may be cal led using FN in the direct

mode, tha t i s , from the keyboard di rec t ly without being in a

programme.



- 6 -SECOND CASSETTE UNIT

The second casse t t e u n i t with lead and plug ready to go s t r a i g h t

onto th e second c a s s e t t e p o r t on th e r e a r o f th e PET" w i l l be

ava i l ab le from the beginning o f June a t a cos t$130 .00 plus P.S.T.

6502 PROGRAMMING MANUALS

This r e a l l y exce l l en t MOS technology genera ted 220 page manual

w i l l be ava i l ab le a t a co s t o f $12.00 plus P.S.Tax from th e

beginning o f May. This manual , if read care fu l ly from the begin-

ning , i s an exce l l en t guide to microprocessor programming in

genera l , as we l l as being a f i r s t r a te 6500 re fe rence book. It

i s worth mentioning here , t h a t fo r those o f you who are i n t e res t ed

in developing t h e i r knowledge and exper t i se in th e f i e ld o f

microprocess ing and cannot , a t th i s p o in t of t ime, af fo rd a PET,

then they might , perhaps , look a ta KIM, a v a ~ u a t i o n

board , which

s e l l s fo r $320 and conta ins a keyboardJd isp lay , 2K ROM plus IK RAM/

cas se t t e i n t e r f a c e , 2 t imers and much more. This valua t ion board

i s ava i l ab le in Canada from Computer shops o r Commodore Business

Yiachines Limited, 3370 Avenue, Agincourt , Ontar io MIW 2K4.

BASIC PROGRAMME STORAGE

Below i s a diagramat ic rep resen ta t ion of the method used by the

CBM bas ic i n t e r p r e t e r fo r s to r ing programmes in memory_



-·7 -

EDITING

There i s an in terest ing property of the screen ed i t rout ine

which gives r i se to the following effec ts : -

I f you inser t using the INS key, more spaces than you type in

characters, the DEL key must be pressed twice the number of t imes

there are spare spaces. E.g. I f you inser t s ix spaces in a

middle of a l ine and only type in four new characters , the f i r s t

two presses of the DEL key wil l produce inverse characters which

wil l disappear on the next two presses. Remember, the INS key

wil l move a l l characters including the one under the cursor

to the r igh t , whilst the DEL key wil l delete the character on i t s

immediate l e f t .



- 8 -

INTERRUPT STRUCTURE

In t e r rup t s ( including Break o r Software In te r rup t s ) are handled

by sof tware pol l ing .

When the p rocessor recognizes an i n t e r r u p t it vec tors through

FFFE, FFFF in ROM to a rou t ine t h a t f i r s t inspec ts th e processor

hardware (IRQ l i n e low) .

I f it was caused by a Break i n s t ru c t i o n , a Jump In d i r e c t i s

executed through l o ca t i o n s 021B, C. I f by a hardware i n t e r r u p t then

a Jump I n d i r ec t i s taken through loca t ions 0219, A.

These loca t ions be ing in RAM may be user-modif ied to p o i n t to

ex t ra user code ahead o f normal i n t e r r u p t process ing .

Note, however t h a t the IRQ poin te r i s used by the casse t t e

rou t ines and should be res to red to standard values before the casse t t e

Save o r Load func t ions a re ca l l ed .

Various sec t ions o f the I/O chips can be s e t up to cause i n t e r -

rupts through th e IRQ l i n e .

Example: POKE 59470,2 enables a negat ive edge on the

user p o r t CAL l ine to cause an i n t e r r u p t .

However, have your code s e t up to handle it when it happens!

Also note t h a t each pass through the reg u la r i n t e r ru p t code

increments the t ime r e g i s t e r .



64

48

32

16·o

I

Q

A

Z$tJ

8..

wS

Xrv

- 9 -

PET Matrix-Decoded KeyboardSee 515 & 516 in table below

7 6 5 4 (3) 2

# $ %.

& \ ( ) ... ho ..,...,. ..

to

E R T Y U I 0 P ..,. 7 8 9

0 F G H J K L 4 5 6

C V B N M . . ? re 1 2 3@ [ ] sp < >S( .96 0 . -

1

de

I

•

+::

16 15 14 13 12 11 10 9

Interesting Locations Accessible from BASIC

Location (decimal)

515

Contents

Byte address of screen l ine with Cursor

Character position of Cursor (0 to 79)

Matrix-coordinate (row+column) of last key down

255 if no key down

~ - - - - - - - - - - - - - - - - - - - - - - - - - - - + - ' ~ . - - - - - - . - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ~ 516 1 if sr.iH down, 0 if shift up

~ - - - - - - - - - - - - - - - - - - - - - - - - - - - 4 . - - -525

526-534

No. of characters h Keyboard 8uffer

Keyboard Buffer

~ - - - - - - - - - - - - - - - - - - - - - - ~ - - - - - - - - - - - - - - - - - - - . ' - - - - - - - - - - - - - - - - - - - - - ~ " - - - - - - - - - 4 Logical numbers of open files78 to 587

588 to 597

598 to 607

Device numbers of open files

Read/write. modas of open file!)

610 How m,my open f i les

r - - - - - - - - - - - - - - - - - - - - - - - - - - . - ~ - - - - - - - - - - - - - - - - - - - - - - - - - ~ - ~ - - - - - - - - - - - - - - - - - ~ - . - - - -512 , 513 , 514

518, 517

59465. 59464

Cluck that increments 60 times () second

Clock that increments 30 times a second?

Clock that decrements every microsecond

~ - - - - - - - - - - - - - - - - - - - - - - - + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ~ 59456

64824

59469

59411

WAIT 59456,32,32 waits fo r v e r t j ~ a l retrace of display

SYS(64824) simulates power-on reset

Interrupt Flag Register; e.9., to input user port CA 1:

I=PEEK(59469} AND 2: POKE 59469.1: IF 1:0 THEN CA 1 low

IEEE PIA B Control, e.g., to run cassette# 1 motor N jiffies:

100 POKE 59411.53: T = I200 IF TI-T(N GuTO 20 0300 POI(E 59411.61

AOVICE: Run motor at lenst 3 jiffies pe r 191 output chars



TIMING TABLES

BASIC STATEMENTS AND 1/0

CONSTRUCT

FREPEEK, POKE

TI$TIGETPOSPRINT X or PRINTPRINT X$iREAD X and DATA 3REM

RESTORETAB

SPC(N)FOR 1 = ... NEXT 1STEP

IFGOTO or GOSUBON A GOTO or GOSUBLl ...... LM

RETURN

APPROX. TIME (MILLISEC)

1 to 101

3 to 41

1 to inf ini ty

1

15 to 1914 + LEN (X$)/290.2 to 20.321 + 0.6*N4.0 + (1 . 6 each)1 .3

0.41.1

0.5 + (0.3*A)+ (0.2*M)

0 .9

Uiing colon, : , saves 0.6 over new l ine .SAVE or LOAD15 sec + (2 sec per 100 char)i . e . 500 baud.

STRING FUNCTIONS

FUNCTION

+ASCCHR$LEFT$, RIGHT$LENMID$STR$

APPROX. TIME (MILLISECl0.5 + (0.2 per char)1

1.23 + (0.025 per char)o to 84 + (0.025 per char)7 to 10

STRING FUNCTIONS (Cont'd

FUNCTION

VAL=, (>,(, <=,),) =

ARITHMETIC FUNCTIONS

FUNCTION

ABSATNCOSEXPINTLOGRND RND (-1)

RND (0)RND (1)

SGNSINTANuser FN

ARITHMETIC OPERATORS

SYMBOL

OtB, IfB21'Belse

/ O/B, A/1else

* O*B, A*Oelse+

=,() , ( , <=,),) =AND, ORNOT



VARIABLES AND CONSTANTS

ITEM APPROX. TIME (MILLISEC)

0.7 to (0.7 + nv*O.l)nv = no. of variablesin program

TIMING PROGRAM

-A,A$,A =,A$ =

AA,AA$,M

=AA$

=A%

At=999.999El6E-16"ABCDE"

M ( I , J • • • • )

0.2 more than aboveO. 3 more than A0.6 more than A =1 per digi t0.7 + (4.2 per d i g i ~ ) 0.2 + (0.4* exponent)0.2 + (3.0* exponent)(0.6 to 0.7) + (0.02per char)(1 to 1. 5) *(no. of subscripts)

MEMORY USAGE (IN BYTES)

10020030040050060070080090010001100

BASIC 1028 (1/0 buffers , tables etc)each statement

N = 300Tl = TlFOR 1 = 1 TREM PUT TESTNEXT 1T2 = TlFOR 1 = 1 TNEXT 1T3 = TlPRINT 1000*END

4 for l ine number and following space,regardless for the l ine ~ u m b e r 1 for each BASIC keyword1 for each other character , includingRETURN

each variable with a value assigned, regardless of spelling or value takes 7 bytes;for string variables, add the length ofthe str ing

each array (N.B., size includes Oth element)take f* (size + 1) + (2 per dimension) where

f=5 for floating point arrays, f=2 forinteger arrays, and f=3 for str ing arrays.

The system slows down noticeably when memory isneary ful l .



Ca.uae . ASC/CHR PEEK/POKE Chat..::t., ASC/CHR PEEK fPOK E Ch . .c ,e, ASC/CHR PEE: KfPOKE Cha,acte, ASCICHR PEEKIPOKE

0 @ 64 0 128 g , 192 641 A 65 1 129 ! a 193 652 B 66 2 130 .• ' .b 194 663 C 61 3 131 +;;; ,c 195 614 D 68 4 132 '; <1 196 685 E 69 5 133 1._ .e 197 696 F 70 6 134

"r

198 707 G 71 1 135 a .8 199 718 H 12 8 136 , .h 200 72

9 I 73 9 131 rt ,1 201 7310 J 74 10 138 :r ,j 202 74

11 K 75 11 139 r- .k 203 7512 L 16 12 140 .1 204 16

ltETU'RN 13 M 11 13 RETUR.N 141 ,m 205 1114 N 18 14 142

" ,n

206 7815 0 19 15 143 I:;:; ,0 207 7916 p 80 16 144

• ,I '208 80

.. 17 Q 81 17 1l' 145 .q 209 81RVS 18 R 82 18 RVSoff 146 I.; , r 210 82HOME 19 S 83 19 CLEAR 147 ,8 211 83DEL 20 T 84 20 INST 148 21'- ,t 212 84

21 U 85 21 149,u

213 8522 V 86 22 150 ,v 214 86

23 io1 87 23 151 ,w 215 8124 X 88 24 152 ,x 216 8825 Y 89 25 153

.y217 89

26 Z 90 26 154 ,z 218 9027 [ 91 27 155 219 9128 \ 92 28 156 IJ 220 92

.!!? 29 ] 93 29 * 157

' ! ' ~ 221 93

30 t 94 30 158 222 94

31 ... 95 31 159 223 95

space 32 32 space 96 32 160 224 96

! 33 33 ! 97 33 IJ 161 97 225 97.. 34 34 .. 98 34 .. 162 98 226 98I 35 35 , 99 35 0 ' 163 99 O· 227 99$ 36 36 $ 100 36 o· 164 100 0 - 228 100

% 37 37 % 101 37 0 ' 165 101 229 101& 38 38 & 102

Ej.166 102 230 102,

39 39,

103 39 167 103 231 103( 40 40 ( 104 40 m 168 104 232 104) 41 41 ) 105 41 ~ i ~ 169 105 ~ . ~ 233 105

* 42 42 * 106 42 170 106 234 106

+ 43 43 + 107 43 rn 171 107 IE 235 107

• 44 44 , 108 44 C. 172 108 [ j 236 108

- 45 45 - 109 45 173 109 Q3 237 109

· 46 46 . 110 46 174 110

Eh238 110

/ 41 47 / 111 47 175 III 239 III

0 48 48 0 112 48 176 112 La 240 1121 49 49 1 113 49 177 113 E!3 241 113

2 50 50 2 114 50

1.

178 114 242 114

3 51 51 3 115 51 179 115 243 1154 52 52 4 116 52 i = ~ 180 116

§!244 116

5 53 53 5 111 53 181 117 245 1176 54 54 6 118 54 Cli 182 118 , 246 1187 55 55 7 119 55 ui 183 119 ..... 1- 247 1198 56 56 8 120 56

B; 184 120 :It 248 1209 57 57 9 121 57 185 121 ~ ; t 249 121: 58 58 : 122 58 ~ . 0 186 122 : - : .0 250 122; 59 59 ; 123 59 187 123 251 123< 60 60 < 124 60 188 124 252 124- 61 61 - 125 61 189 125 253 125> 62 62 > 126 62 r;J 190 126 254 126.,

63 61.,

l27 63 19' . 1 ~ 1 2.55 127· .



~ C D r n r n D d D r e PET ™

erogram Announcement No.1

OSERO AND REVERSE

Osero is Commodore's version of Othello, a game of

strategy played on a 8 x 8 board, much like a chess or

checkers board. The object is to surround your enemyand convert the enemy pieces to your side. It's a gamewhere the last moves can be quite decisive; you may be

winning tremendously (or losing) but the positions canbe reversed at the very last moment. You play againstthe PET brain.

Reverse is another game to tax your intelligence andlogic. The numbers 1 through 9 are on the screen inrandom sequence. The idea is to put these numbers into

orderin

as few moves as possible. Your logical thinkingwill get quite a work-out.

Both games are for adults and older children. 8K of

RAM is required. Order Part No. 321001 $10.95

DIET PLANNER AND BIORHYTHM

Diet Planner (by Les Palanik) first determines the idealweight for your height, your age, your sex and your

body frame. It then asks for your leve-l of physicalactivity. Then it calculates precisely the number of calories you need each day to maintain whatever weightyou indicate. Should you wish to lose weight, yourPET will display the caloric intake required and thephYSical activity, on a day by day basis, to help you

reach the desired objective. It works.

Biorhythm will indicate your intellectual, emotionaland physical cycles according to a well regarded series

of computations based on behavior. Enter your name.your birth date and then indicate which 39 day periodyou're interested in. On an accurately drawn chart . thedisplay will show the highs and lows for each of thethree cycles: intellectual. emotional and physical. Youshould know, on a given day, that all three cycles may

very well be at peak. Perhaps that would be a good dayto undertake new ventures . . . Fascinating.

Both require 8K of RAM.

Order Part No. 321002 $15.95

TARGET PONG AND OFF THE WALL

Target Pong: Insert paddles in the path of a fast moving

ball to deflect the ball into a target. The secret is touse the fewest number of paddles and the least time tohit the target just once. It's really much more difficultthan it sounds. It requires dexter ity and guaranteesyou fun.

orr The Wall is exactly the opposite. Here the secret is

to use as many paddles as you can without hitting thetargets. And just to make the game more difficult,there are many targets in this game.

Both are quite suitable for children of almost all agesand for adults, too. There are various levels of diffi-culty: the size of the target can vary in Target Pong;the number of targets can be increased in Ofr The

Wall. Both games can keep score for two players. Re·

quires 8K of RAM. Order Part No. 321003$10.95

A TREASURE TROVE OF GAMES ;JiiLunar Lander-one of the all time popular favorites. Youmust make the Lunar Excursion Module land softly onthe moon. By regulating the falling speed. the counter·

thrust or the rockets and the amount of fuel required,you should be able to accomplish this objective. I f you

Iaail. the marvelous graphics will show the Lunar Landersmashing to the surface of the moon. Difficult at first,but fun to master.

Rotate is a puzzle on a 4 by 4 grid. The secret is to ar

range the letters in sequence in as few moves as.possible.Very tough at first. But it can be done.

Wumpus is a delightful voyage in the imagination. full

of fun and quite educational, too. You're required to bea detective on a treasure hunt. The dues are all givenand you must find the Wumpus, on the basis of these

"lues. and get him before he gets you.

Tic Tac Toe. See if you can beat your PET at this old

reliable game. ..These games and puzzles will particularly fascinate the eounger people in your family . . . although we thinkadults will like to play along. Requires 8K of RAM.

Order Part No. 321004 $10.95

BASIC BASIC (By Ralph James andRon Lodewyt.:k)

A real tutorial program. introducing you to the BASIClanguage. Thoroughly interactive: your PET will teachyou how to operate your PET! You proceed at your

own pace. You should actually be able to learn PET'sBASIC in several hours and then begin your own pro·gramming. Basic BASIC is written by two very experi·enced college professors. The topics covered include linenumbers. variables. strings, arrays. and the use of thevarious commands such as LIST. RUN, and SAVE.Also basic keywords will be explained and used such as

PRINT, READ/DATA, INPUT, IF/THEN. GOTO,and FOR/NEXT. Fifteen chapters, six sample pro·grams . . . and homework assignments. :::

ses just 4K of RAM memory.Order Part No. 321005 $15. 95

March 1978



( : . carnrnadare PET ™

SQFTWARE PRQ(;RAMS

GALAXY GAMES I By Peter Rudz)Here are two tough hut entertaining games. In both.

you're required to maneuver yom space ship while

firing at the enell1Y, and at the same time. to avoid

hitting a star. In one game. you're firing al fixed targets.

In the other game, you're firing at a spaceship that's

being piloted by an obviously drunk astronaut! Ab·

solutely no accounting for the gyrations the enemy

spaceship is going to take.

Requires 8K of RAM.

Order Part No. 321006 $10.95

MORTGAGE

Almost a misnomer, because this program is suitable

not only for people considering buying or selling prop

erty bu t also for anyone contemplating borrowing or

lending money. Enter the principal amount. the term

and the annual interest rate and the PET will compute

the periodic payments, the total payments and the total

interest for your mortgage. You enter the starting date

and the PET will display monthly , quarterly. semi·

annual or annllal payments. The stat iS of the mortgage

(or loan) at any date can then be displayed, showing

the interest/principal split of the previous payment. the

interest, principal and total paid thus far and still out·

standing and the number of payments remaining.

Ideal for home owners and borrowers. real estate people.

banks. Requires 8K of RA!\1.

Order Part No. 321007 $15.95

DRAW POKER

Perhaps we've been minimizing the quality of the superb

graphics available in all these programs. But with Draw

Poker and with Black Jack (the next listing) you have

perfect examples of the kind of graphics we're talking

about. Here you plJy Draw Poker against the house

with two pair or better to win. And we must give yuu a

warning: the house is a very tough-bul fair--dealer. Ofcourse, the house is your PET. You CJIl VJry your be t

and see how much you can win (o r lose).

Requires 8K of RAM.

Order Part No. 321008 $10.95

BLACKJACKPlace your bet and watch your PET deal out the cards

as you try to beat the house. You'll swear you're in Las

Vegas. Each card is shown, with the aid of the superior

PET graphics. as close to life-like as you can imagine.

Requires 8K of RAM.

Order Part No. 321009 $10.95

SPACE FIGHT (By Leonard K. Sweatman)

Fire missiles at each other in this two player game. But,

there's a warning; each missile has limited range and if

the missile doesn't hit the enemy, watch out! You could

run into your own missile and lose . . ,and feel very silly.

A game for all ages. With emphasis on the younger

people. Requires 8K of RAM.

Order Part No. 321010 $10.95

* * *This brings li S to the end ofour March offerings, an

historic evem. 17lis is the ~ ' e r y first time that programs

hal'e been offered for the PET computer. But we prom·

ise you that there will be mallY more releases next

month and ill tilt: months to come. Commodore hasevery intention ofoffering one of the most complete

libraries o fprograms that has ever been oJferedanywhere. .

You mig/II want fO lise rhe I'ery handy orJer form

we're ene/osing.

Documents

The Transactor V1 01 1978 New