Commodore MAX Machine

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Commodore MAX Machine
Commodore MAX Machine
Type: Home Computer
Producer: Commodore
Price: JP: ¥34,800, DE: 498 DM, (ca. 250 €) US: $200 (ca. $560)
Released: 1982
Discontinued: 1982
Processor: MOS 6510 @ ca. 1 MHz
Memory: 2.5 KByte
OS: Only with cartridge Mini BASIC I or BASIC V2.0
Info: alias Ultimax (USA) or VC10 (Germany)

The Commodore MAX Machine was released in 1982 and was only sold in Japan for ¥34,800[1]. The MAX Machine used the same architecture as the C64, but only had 2 kilobytes of RAM compared to the C64's 64 KB and had greatly reduced functionality. About 50,000 units were produced during 1982. In Germany it was called the VC-10 and Ultimax in the US, though it likely never saw a release in either region.

Because of its limited capabilities, and the popularity of the more capable VIC-20, the MAX Machine was quickly discontinued.

Hardware differences with the C64[edit | edit source]

Compared to the Commodore 64, the MAX Machine has a number of hardware differences, including the following:

  • Only 2 KB of RAM compared to the C64's 64 KB
  • A membrane keyboard instead of a full-travel keyboard
  • RF output with mono audio via a 1/8" jack; the C64 has RF output in addition to composite, chroma/luma and mono audio via a DIN connector
  • One joystick port on each side of the system; the C64 has both joystick ports on the right-hand side
  • Rear-mounted power connector and power switch; the C64 has these on the right-hand side
  • No Serial Port, meaning no external devices such as a disk drive or printer
  • No User Port
  • No ROM is present, meaning a cartridge must be present to provide functionality,
  • Access to the datasette is only possible with the "MAX BASIC" cartridge, and the maximum program size is 2 KB

BASIC[edit | edit source]

To use the MAX Machine with an OS like BASIC one must plug in one of these two cartridges:

MINI BASIC I[edit | edit source]

Start screen of MINI BASIC I.

The cartridge MINI BASIC I contains a cut-down BASIC V2 with 510 free bytes.

The following commands are missing: ATN, CLOSE, CMD, COS, DEF, DIM, EXP, FN, INPUT#, LEFT$, LOAD, LOG, ON, OPEN, PRINT#, RIGHT$, SAVE, SIN, SQR, TAN, USR, VAL, VERIFY and WAIT.
All error messages (except for INPUT error messages) are displayed as numbered codes. For example, ?SYNTAX ERROR is displayed as ?ERROR2. Because of the cut-down command list, there are only 14 error codes, numbered 1-15 (13 is not used):
Error Code Error
13 Not used

"MINI BASIC I" cover
Mini BASIC PCB, upper
Mini BASIC PCB, lower

MAX BASIC[edit | edit source]

The MAX BASIC cartridge contains the full BASIC V2 with 2047 free bytes.

"MAX BASIC" cover
"MAX BASIC" PCB, upper
"MAX BASIC" PCB, lower

Construction[edit | edit source]

Interfaces[edit | edit source]

rear view

Most connections are on the rear (from left to right):

  • Power on/off switch
  • Power connection (7 pin DIN female) for the power supply (4 pin DIN male)
  • Audio connection (1/8" jack)
  • Expansion Port (44 pin; I/O)
  • Channel select (channel 1 or 2)
  • RF out (RCA jack)
  • Datasette connector (Cassette Port; 12 pin; I/O) for connecting a 1530 or C2N

There is a Control Port on each side of the system.

Mainboard[edit | edit source]

Original package

The MAX Machine uses either an Assy 325565 Rev.A or Rev.B board.

  • Processor: MOS 6510 with ca. 1 MHz clock
  • Memory: 2 KB RAM (M58725P) + 0.5 KB Color RAM
  • Graphics: VIC-II (MOS 6566)
    • Display in text mode (large letters/graphic symbols or large/small letters) 40 (columns) * 25 (rows) chars or in graphic mode (HiRes) 320*200 pixels in 16 colors, 16 frame colors and 16 background colors (additional 8 sprites (HiRes or Multicolor) in BASIC
  • Sound: 6581 SID
  • Miscellaneous: One interface chip CIA (MOS 6526) for I/O (Input/Output), PLA 6703
  • Operating System: None, must be supplied through cartridge ("MINI BASIC I" or "MAX-BASIC")

Specifications[edit | edit source]

The serial number is always greater than 10000!
  • Dimension: MAX Machine: 350x185x60mm, Box: 445x330x140 mm
  • Weight: 1820 g
  • Keyboard: Membrane keyboard with 66 keys (QWERTY layout)
  • Power supply: 5V DC and 9V AC
  • Power consumption: 25W
MAX Machine power supply

Ultimax-mode[edit | edit source]

MAX Machine cartridges are compatible with the C64, since the C64 has a MAX Machine compatibility mode. Freezer cartridges for the C64 used this compatibility mode to write their ROM in the address section of the hardware interrupt vectors $FFFA to $FFFF (for normal C64 cartridges, these addresses are not accessible) and so they can freeze a program without crashing the CPU or modifying the RAM content.

Block diagram[edit | edit source]

MaxMachine block diagram.png

Memory map[edit | edit source]

Memory map (hex) Memory map (decimal) Standard configuration Cartridge Mini Basic I Cartridge Max Basic
$E000-$FFFF 57344-65535 - 8KB Kernal/BASIC/Char-ROM 8KB Kernal/Char-ROM
$D000-$DFFF 53248-57343 I/O-area I/O-area I/O-area
$A000-$CFFF 40960-53247 - - -
$8000-$9FFF 32768-40959 - - 8KB Basic-ROM
$1000-$7FFF 4096-32767 - - -
$0800-$0FFF 2048-4095 - - 2KB RAM (on the cartridge)
$0400-$07FF 1024-2047 screen RAM screen RAM screen RAM
$0200-$03FF 512-1023 0.5KB RAM 0.5KB RAM RAM (system area)
$0000-$01FF 0-511 RAM (zeropage, stack) RAM (zeropage, stack) RAM (zeropage, stack)

Note: Green background means free BASIC memory.

Cartridges[edit | edit source]

Game cartridge: Gorf 3404
Game cartridge: Billiards 3510
Game cartridge: Slalom 3512

Most MAX Machine cartridges were published in 1982 and all were only released in Japan. They can be also used on the C64.

Part No. Name ROM-size ROM-chip Description
3101 Mini BASIC I 8KB 901233-01 (Kernal+BASIC+Char) Application
3102 Max BASIC 8KB
901231-01 (Kernal+Char)
901230-01 (BASIC)
HM6116P-4 (RAM)
3201 Music Composer 8KB Application
3401 Omega Race 8KB Game
3402 Wizard of Wor 8KB Game
3403 Kickman 8KB 325362-02 Game
3404 Gorf 16KB Game
3501 Avenger 8KB 325350-01 Game
3502 Jupiter Lander 8KB 325351-01 Game
3503 Super Alien 8KB Game
3504 Radar Rat Race 8KB 325352-01 Game
3505 Road Race 8KB Game
3508 Mole Attack 8KB Game
3509 Clowns 8KB 325356-01 Game
3510 Money Wars 8KB 325357-01 Game
3511 Bowling 16KB Game
3512 Slalom 16KB Game
3xxx Le Mans 8KB Game
3xxx Billiards 8KB Game
3xxx Music Machine 4KB Application
3xxx Pinball Spectacular 16KB Game
3xxx Sea Wolf 8KB Game
3xxx Speed/Bingo Math 8KB Game / Learning software
3xxx Visible Solar System 8KB Application

MultiMAX Cartridge[edit | edit source]

The MultiMAX [2] is a cartridge for the MAX Machine developed by Rob Clarke and Michael Pleban. It was introduced at the Vintage Computing Festival in New Jersey in April 2014. The price of a complete cartridge is US$29.95 [3] plus US$4 for shipping (albeit uninsured), although it is sold out as of December 2020. It is also compatible with the C64 and C128.

The MultiMAX PCB uses a 1 megabyte EPROM (27C801) which contains all published games and applications for the Commodore MAX Machine. A 2 kilobyte RAM chip (6116) is also installed, as it is required for "MAX BASIC". After powering on the computer, a program menu appears where the user can select a program. The cartridge has also a reset button so the user can switch between programs without needing to power cycle the computer.

MultiMAX cartridge
MultiMAX menu

References[edit | edit source]

  1. Commodore MAX Machine commercial
  2. MultiMAX Cartridge
  3. MultiMAX selling price

Links[edit | edit source]

WP-W11.png Wikipedia: Commodore MAX Machine