Classic Computer Magazine Archive COMPUTE! ISSUE 53 / OCTOBER 1984 / PAGE 46

Commodore Prepares To Roll Out The Plus/4

Selby Bateman, Features Editor Tom R. Halfhill, Staff Editor

Here's a hands-on report on Commodore's new Plus/4, a $300 64K computer with built-in productivity software scheduled for release this fall Commodore calls it "The Productivity Machine."

Commodore's new Plus/4 computer is an interesting hybrid: part programming machine and part productivity package.

Commodore says the Plus/4 is not a replacement for the popular Commodore 64, but instead addresses a new market with an emphasis on practical applications for home and small business. It will be accompanied by a new line of peripherals—some of which are compatible with the 64 and VIC-20—plus a scaled-down 16K version, the $100 Commodore 16, which replaces the discontinued VIC.

At the heart of the Plus/4 and Commodore 16 is the new 7501 microprocessor, an eight-bit chip which is machine language-compatible with the 6502/6510 found in the VIC and 64. However, because of memory differences, practically no VIC and 64 software will run on the Plus/4 and Commodore 16.

Since announcing the Plus/4, Commodore has wavered about whether it will actually market the computer. As of this writing (mid-August), Commodore began shipping review units to major magazines and was preparing to launch a national advertising campaign October 8, so it appears the Plus/4 will hit the shelves barely in time for the Christmas season.

Improved Features

As a programming machine, the Plus/4 has several advantages over the two-year-old 64. It has a new, more powerful BASIC (BASIC 3.5) with over 75 commands, including more than a dozen for sound and graphics. There's a built-in machine language monitor with 17 commands. There are 16 primary colors, just like the 64, but each color now has eight luminances (shades), for a total of 128 hues. You can define an independent window anywhere on the screen by specifying its upper-left and lower-right corners, and all subsequent screen output will be redirected to this window. And a new bank-switching technique leaves the 64K computer with a spacious 60K RAM for BASIC programming.

As a productivity machine, the Plus/4 has four application programs built into ROM: a word processor, a spreadsheet, a file manager, and a business graphics generator. All the programs are integrated with each other. For example, a portion of the spreadsheet can be cut and pasted into a document on the word processor. There's also a windowing capability so you can display two of the programs on screen at once. Commodore's marketing strategy for the Plus/4 centers on these built-in applications, titled 3-Plus-l. They were developed for Com­modore by International Tri Micro.

The Commodore Plus/4 may finally reach dealers this fall.


The Plus/4's keyboard differs slightly from those on the 64 and VIC. Above the keyboard are four special function keys with eight predefined functions: RUN 3-Plus-l, DLOAD (disk load), DIRECTORY, SCNCLR (screen-clear), DSAVE, RUN, LIST, and HELP. The new KEY command lets you display the functions currently programmed for each key and easily re-program them yourself.

The main keyboard has 59 typewriter-like keys and four separate arrow-shaped cursor keys. All of the standard PET/VIC/64 graphics characters have been retained on the front of the keycaps, with two additions: FLASH ON and FLASH OFF, to display flashing characters on the screen. The Plus/4 keyboard feels looser and springier than a 64 keyboard, very much like the Commodore SX-64 transportable.

There's also a reset button next to the power switch. It's a cold-start reset that normally wipes out any program held in memory, but if you hold down the RUN/STOP key while pressing it your program will not be harmed.

Peripheral interfaces have been changed on the Plus/4. While it can use the same 1541 disk drive and serial printers designed for the VIC and 64, the Plus/4 has a parallel port for a much faster drive, the SFS-481. The Plus/4's cassette port and two joystick ports are not compatible with current Commodore cassette recorders and game controllers. Another port resembles a Commodore 64 ex­pansion port and is labeled "Memory Expansion," although no expanders for the Plus/4 have been announced. Finally, there are two video output jacks: one for standard composite monitors (including the Commodore 1701/1702), and another which feeds RF signals to a TV.

Despite these improvements, the Plus/4 lacks a few significant features found on the less expensive 64. There's no sound synthesizer chip—just two tone-generators which do not offer the flexibility of the 64's SID chip. And although the Plus/4 has 128 colors and a high-resolution graphics mode of 320 X 200 pixels, it has no sprites. So the Plus/4 and Commodore 64 are differentiated by more than just $100 in price. The Plus/4 is better suited to more "serious" applications and programming, while the 64 has superior graphics and sound.

Instant Software

When you turn on the Plus/4, you can immediately run the built-in software by pressing the Fl function key and then RETURN. Since 3-Plus-l is in ROM, there's no waiting for a disk or tape to load. The computer runs the software instantly, defaulting to the word processor.

You control 3-Plus-l by typing two-letter commands at a special screen prompt. The prompt appears when you press the Commodore logo key and C key. For example, to leave the word processor and enter the spreadsheet, you type the command TC ("To Calculator").

Although having four integrated programs instantly available is a powerful feature, not all of the programs are as powerful as software available separately. The word processor may be the weakest link. For one thing, it limits you to only 99 lines of text, so extended documents are beyond its scope.

Second, the word processor's editing functions are a bit unusual. When you insert characters, the entire document is pushed forward on the screen, not just the text up to the next carriage return. You can disable this movement, but then words start wrapping around into half-lines. Also, the text scrolls hori­zontally as it's entered to simulate an 80-column (actually 77-column) screen. This can take some getting used to unless you've previously worked with horizontal scrolling. Your text marches off the screen to the left as you type, and then wraps around at the start of the next line. Therefore, you can't view a whole sentence on the screen at once, unless it's less than 40 characters long.

New Name, Same Machine

The Plus/4 was originally announced at the Winter Conssumer Electronics Show (CES) in January as the Commodore 264. Although the name has changed, the design is essentially the same—with one important difference. The 264 was going to be offered in several different configurations. Buyers could pick what applications software they wanted built into the computer.

By the Summer CES in June, Commodore had abandoned that concept. Apparently dealers had rebelled against the idea of installing their own ROM chips or stocking many models of the same computer. Commodore also dropped plans to introduce the Commodore 364, a deluxe version of the 264 with a speech synthesizer and numeric keypad.

Commodore plans to release about 30 programs for the Plus/4 to coincide with the computer's introduction. These will consist primarily of productivity packages, with some educational programs and a few of the most popular games available for the 64.

The on-again, off-again history of the Plus/4 means it's possible that Commodore may decide at the last moment not to release the computer. However, a source working with the company claims "all systems are go."

Commodore is obviously banking on its assessment that the next large segment of the computer-buying population wants a productivity-oriented machine at an affordable price. At the same time, the company will closely watch how the new computer affects the Commodore 64, a phenomenally popular computer which continues to sell briskly.