The Maxxi was one of the first Brazilian clones of the Apple II and Apple II+.
It was manufactured in 1982 by Polymax, a subsidiary of Abicomp, which headquarters were located in Porto Alegre. Polymax also manufactured larger computers for commercial applications.
It has a slightly different design than other Apple-compatibles, with a taller case that supposedly facilitated internal ventilation.
Due to the success of Apple in the North American market, several Brazilian manufacturers produce Apple compatible computers, to benefit from one of the largest application software libraries available in the world.
Maxxi followed the same philosophy as Apple, facilitating user access to internal circuits. Despite having a design a little different/taller from other Apple II compatibles, Maxxi has the same electronics as the original North American product. Its case has a cover that can be easily removed, giving access to the circuit board and expansion connectors.
Based on the 6502 microprocessor, the Maxxi operates at a clock frequency of 1 MHz. The user has at his disposal eight internal connectors (slots) where he can place memory expansions, printer interfaces or floppy disk drives expansion cards. It's also possible to add a very large set of expansion boards, with the most diverse functions.
The 12 KB ROM contains in addition to the operating system (monitor), the Polysoft BASIC language. RAM can go from 16 KB to 64 KB on the motherboard itself. Thanks to the expansion board and software-aided addressing, the RAM memory can go up to 128 KB.
Like all computers of the Apple lineage, the Maxxi can be operated with a second microprocessor through a Z80 expansion card. It then can use CP/M, widely used in larger microcomputers and featuring a large number of programs for commercial applications. The RAM memory added by the Z80 board overwrites the ROM memory, which can only be used by the 6502, resulting in 64KB of RAM, available to the CP/M.
Maxxi has four analog inputs for connecting game controllers (joysticks); without the need for additional interfaces, a cassette recorder can also be connected as an auxiliary memory unit.
Depending on the number of expansion boards placed in the Maxxi, ventilation may be necessary to avoid heating problems. This is performed by a small fan attached to the side of the power supply, ejecting hot air outside of the Maxxi.
Maxxi's ON/OFF switch is located in the top right corner of the case instead of being on the back panel as with other models in the Apple family. On the back are the connectors for the cassette recorder, the output for the video monitor and three holes for peripherals cables such as floppy disk drive and printer.
Maxxi's keyboard is QWERTY with 51 keys. As with the other models based on the Apple II Plus, the keyboard is relatively simple, with no separate numeric keypad or full cursor movement keys (only left and right). Some characters, which are obtained with the combination SHIFT and other alphabetic keys, are not engraved on the keys. For example, the @ character is obtained with the SHIFT-P keys. With the ESC key, you can move the cursor to a certain position on the screen and edit the content of a program line, or "use" a command already written to execute it again. By pressing ESC once, the I, J, K and M keys command the cursor movement in the four directions. Pressing ESC again turns the cursor movement mode off. On the other hand, the simultaneous combination of the CTRL key with some alphabetic keys results in control commands, such as processing interruption (CTRL-C), sounding alarm (CTRL-G) and others.
The default video output of the Maxxi is composite. Altogether, sixteen colors can be generated, producing color images with low or high resolution. Working in high resolution, the number of available colors is reduced to six, two of them with two different shades.
The default text resolution consists of 24 lines of 40 columns with uppercase characters only. Low graphic resolution offers 40 x 48 (big) pixels or 40 x 40 pixels plus four lines of text at the bottom of the screen. At high resolution you can access 280 x 192 dot graphics on the full screen or 280 x 160 dot graphics with four lines of text. At high resolution, Maxxi uses 8 KB from the main RAM. 80 columns display is possible with an expansion card.
For data storage, the Maxxi uses a tape recorder in its most basic version. The data transfer and read speed for the cassette is 1200 baud, or approximately 120 characters per second. You can of course add floppy disk drives and hard disk drives (Winchester type). Each 5 ¼-inch floppy disk drive can store approximately 150 KB. Each floppy disk control board (interface) can command two floppy disk drives.
The operating system and the BASIC language, residing in 12 KB of ROM, are the same as the original Apple II+. The disk operating system is compatible with Apple DOS 3.0, and Polysoft BASIC with Applesoft, both with translated error messages in portuguese. DOS needs to be loaded and works in conjunction with BASIC. The characters shown on the screen can be in reverse, flashing or normal mode.
Using the Z80 expansion board with the CP/M operating system, instead of using ROM-resident BASIC, you can have use many other languages such as MBASIC and CBASIC, COBOL, FORTRAN, etc.