In and Out of SYNC

The Commodore 64

John Anderson

The Commodore 64 is the best-selling machine in its class, and for very good reason. At under $200, it is quite a buy. With 64K RAM, superlative color graphics, and sophisticated sound synthesis capability, the C-64 packs a lot of punch. It also has a ROM cartridge slot, full-stroke keyboard with four function keys, and an expansion bus.

Commodore, which began years back as a business furniture and calculator company, was among the first manufacturers to offer an assembled microcomputer. It introduced the Commodore Pet in 1978. And despite the fact that the initial machines were slightly flaky and sported the most unfriendly keyboards around, the Pet remains a sight in many homes and schools. It is at the least remembered fondly by many a micro enthusiast.

When the 5K Vic-20 was first introduced in 1980, it met with little enthusiasm. At $300, the machine was too cheap for serious hobbyists, and too expensive for the fledgling mass market. So it languished for a while.

But Commodore kept right on pushing the machine, and, to the chagrin of the industry, made cost-cutting its basic strategy. The Vic-20 offered a taste of color graphics and sound, and sported a full-stroke keyboard. By the time the mass market for microcomputers really began to heat up (Christmas of 1981), the Vic-20 was selling for $200. It had some decent software, too, though mostly from third-party manufacturers. And so it began to catch on.

By Christmas of 1982, over a million Vic-20s had been sold, and they continue to be sold today, at prices well under $100. Without a doubt, the Vic was the
first true mass market machine. It set Commodore afloat.

Meanwhile, engineers at Commodore continued to improve the Vic, giving it advanced capabilities and a quantum leap in RAM. In early 1983, the Commodore 64 was christened. It was news even at a list price of $595, but it did not stay there for long. Soon after the introduction of the C-64, the first volleys of a bloody, and now legendary, price war were heard.

During this time, the price of the Timex Sinclair dropped from $150 to $50. Commodore prices dropped just as dramatically. And the real winner of the hardware wars was you, the consumer.

One of the strong points of the C-64 is its processor, the 6510. Its architecture is modeled after the 6502, which is the heart of the Apple and Atari micros. As a result, high quality translations of Apple and Atari games and application software have become available. This library will continue to grow.

But the Commodore 64 is not without its problems. Never known as a company with a remarkable support system, they have run aground on a few reefs of their own making.

Problems with reliability have plagued the C-64 since its inception, and though these problems seem largely to have been solved, there is still a ghost in the machine. Early 64s suffered from serious video problems. Later runs turned up units that were D.O.A. (dead on arrival).

Then there is Commodore 64 Basic. It was pulled over from the Pet and Vic machines, without much alteration. As a result, many of the advanced capabilities of the C-64 cannot be accessed from Basic without recourse to complicated PEEKs and POKEs. Simon’s Basic, an improved language with powerful commands that allow Basic to finally latch in to the potential of the C-64, has just been released. It is the brainchild of a sixteen-year-old programmer from Britain. Not too many serious C-64 enthusiasts will do without it for long. Programming graphics and sound is just too tedious from plain old Basic.

Still, the C-64 can do many things that the more expensive machines can do, and has grown to be a market presence that cannot be ignored. And if the Coleco Adam ever manages to become a marketing force itself, Commodore is ready to cut its prices once again. It’s hard to argue with a strategy like that. At $99.95, the C-64 would be hard indeed to beat.

Changing Colors

David Grosjean

Although many computers have the ability to use colors, the system for using the colors varies from machine to machine and sometimes becomes quite confusing. On the TS2068 and the JR200, for example, the system is rather simple. In this issue we compare color changing on the TS2068 and the Commodore 64 and on the TS1000 which is limited to black, white, and gray.

Cursor Color

Changing the color in which the cursor prints is easy on both the TS2068 and the C-64. On the C-64, color is produced by holding down the CTRL (control) key and pressing one of the number keys 1 through 8, e.g., CTRL 3 produces red. Using the Commodore key instead of the CTRL key produces 8 more colors.

If you are typing in direct mode, changing the color immediately starts the cursor printing that color; however, if you are typing a PRINT line of a program and you wish to change the color, the computer inserts a control character instead of directly changing color. E.g., type

30 PRINT "(CTRL 2) SYNC"

Where you hit CTRL 2, there is an inverse E. When you run this, that inverse E does not show up, but “SYNC” will be in white.

Producing the same effect on the TS2068 is easier. No matter where you are typing, if you change color, the cursor starts to print in that color; there are no control characters. The colors are on the number keys, just as on the C-64. To change colors, push the CAPS SHIFT key and the SYMBOL SHIFT key to get the E cursor. Hold down the CAPS SHIFT key and press the number key of the color you want. You are ready to type. Try the same test used on the C-64.

Borders and Backgrounds

You can also change the color of the border of the screen and the background on both computers.

On the C-64, POKEing a number (1-15 each corresponding to a different color) into location 53280 changes the color of the border. E.g., 40 POKE 53280,2 changes the border color to white. Similarly, POKEing into location 53281 changes the background color.

The following program simply changes the colors of the border and background incrementally with a loop (x). Line 60 is a delay loop.

C-64:
10 X=X+1
20 IF X>15 THEN X=0
30 POKE 53280, x
40 POKE 53281, X+1
50 GOTO 10

The TS2068 has several commands that make changing colors easy. To change the border, simply type BORDER and the number of the color. Also, the background can be changed with the command PAPER and the color number. The background, however, does not change until the screen has been cleared. E.g., type in

10 BORDER 1:PAPER 2:CLS 

RUN this. You will see that the border is blue and the background is red. Add these lines:

20 PAPER 7:PRINT "In and out of Sync" 30 PRINT "colors" 

RUN this. The background is red, but the background of the letters is white. Clear the screen (CLS and ENTER) and the entire background is white.

Individual Characters

You can control the color of individual characters on the screen. The C-64 has a color memory that stores the color of every character on the screen. To change the color of any one character, just POKE the new color into the correct location in this color memory which starts at location 55296 and is 1000 locations long (the screen has 40 x 25 characters). The following program fills the screen with circles and then changes the color of a randomly chosen circle.

C-64:
100 FOR I=1 TO 960
110 PRINT "O"
120 NEXT I
130 POKE 55297+INT (960RND (1)), INT (16RND (1))
140 GOTO 130

On the TS2068 to control the color that characters are printed in, type in INK and the color number. To illustrate this, change line 20 of the TS2068 program above to:

20 INK 1:PAPER 5:PRINT "In and out of Sync"

This gives blue letters on a cyan background. Remember, you can change any of these in immediate mode.

The following few lines better illustrate the use of INK.

TS2068:
100 INK INT (8+RND)
110 PRINT "abcde\a\b\c\d\e"
120 GO TO 100

In line 110, the second half of the string is inverse. Since it is inverse, instead of the characters being the INK color, the PAPER will be the INK color and the character will be the original PAPER color. The INK and PAPER colors are easily reversed by the INVERSE command.

Other commands of the TS2068 that control the display are FLASH, which flashes the specified text, and BRIGHT, which brightens anything printed. Each of these functions is turned on by typing the function followed by a 1, and turned off by typing a 0; e.g.,

FLASH 1:PRINT "HELLO":FLASH 0

Although the TS1000 has is limited to gray, black, and white, still interesting screen displays can be created. The following lines simply fill up the screen with graphics A’s. The other (very close) shade of gray is the graphics on the H key. For a black background, use an inverse space.

TS1000:
10 FOR I=1 TO 22
20 PRINT "\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::\::"
30 NEXT I

We have seen that using colors on the TS2068 and Commodore C-64 is easy. The TS2068 uses the easier functions BORDER, PAPER, and INK. Changing text color on the TS2068 does not require POKEing. Using color and changing color on the C-64 is rather cumbersome. The color of the border and background must be changed by POKEing the correct numbers, while changing text colors uses control characters or POKEing into the color memory. The TS1000 can use black, white, and two shades of gray to add at least some flavor to a screen display.