Commodore LCD

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Commodore LCD
Commodore LCD (Prototype)
Type: Home and Business Computer
Producer: Commodore Business Machines
Price: Estimated 600 USD (1984 prices)
Released: NA
Discontinued: NA
Processor: MOS Technology 65C102
Memory: 32kB
(internally expandable with 64kB)
(externally expandable with 64kB)
Info: Also known as CLCD

The Commodore LCD (abbreviated CLCD), is a prototype 8-bit computer with a Liquid Crystal Display (LCD) by Commodore Business Machines.

History[edit | edit source]

The CLCD was developed in late 1984 and first presented to the public at the January 1985 Consumer Electronics Show (CES) in Las Vegas. Following the break-up of the Plus/4 project teams, a number of personnel worked on minor projects that could be developed further. One of these was implementing an LCD screen. Commodore Semiconductor Group (CSG) had an optoelectronics division (at 4350 Beltwood Parkway South, Dallas, Texas, 75234) where research and manufacturing for LCD digital watches took place. In fact, this was the only LCD glass manufacturing company in the USA at that time. Along with portability, there was the intent to include a modem.

It is believed that Commodore’s CEO, Marshall Smith, spoke with the CEO of Tandy about the future of LCD products. When Smith was told that LCD would be going nowhere, he cancelled the project. With no need then for LCD technology, and no real calculator or watch production going on at Commodore, Smith sold-off the entire LCD division. There are rumoured to be 5 machines in existence, however only 2 are verifiable.

Contributors[edit | edit source]

Bil Herd worked on the initial architecture for the CLCD project and also designed the unimplemented MMU, before being moved to the team developing the C128. Jeff Porter, a self-confessed C64 hacker, from AT&T was the modem expert and became leader of the project team when Herd was moved. Ian Kirschman was a lead on the project. Hedley Davis, Judy Braddick, Andy Finkle, and Carolyn Scheppner were coders.

Concept[edit | edit source]

The CLCD was to be "a utilitarian computer for those of you who need a small, light, portable computer for use on the road, in the classroom, or simply in a remote room in your house"[1]. Jeff Porter has stated that he was recruited by Commodore to design "the machine you'd want for yourself" [2]. It was not meant to be a laptop computer, but more of a notebook computer.

Construction[edit | edit source]

Table 1 - Construction of the CLCD
Aspect Detail Image
Dimensions • Width: 11.75" (29.85 cm)
• Depth: 11" (27.94 cm)
• Height: 2.18" (5.54 cm)
• Weight: 5 lbs
Commodore LCD (Prototype)
Top Side • Flip-up hinged LCD screen
• Sliding cover for internal memory expansion
• Mitsumi low-profile 72-key keyboard featuring:
•• 8x function keys, F1 -F8 , non-shifted
• Arrow-shaped cursor keys
• Power button
CLCD top side
Left Side • Power Port +6V DC (unknown connector)
DTE/DCE jumper (DIN rail toggle switch)
DTR/Acoustic Coupler jumper (DIN rail toggle switch)
Acoustic coupler port
• Phone port
• Line port
Barcode Reader port (HP compatible)
CLCD left side
Rear Side • Contrast dial (rotary encoder)
• Master Reset button
Expansion Port (50-pin male connector)
• Master Reset button
Serial Port (6-pin DIN connector)
• Centronics Port (IEEE 1284 36-pin male connector)
RS-232 Port (DB-25 female connector)
CLCD rear side

Technical Specification[edit | edit source]

  • Power:
    • 4x 1.5V NiCd AAA batteries (5 hours of use)
    • 6V DC
  • Central Processing Unit: Rockwell 65C102 @ 1MHz
  • Memory:
    • RAM: 32kB static CMOS (internally upgradable with 64 kB, and externally upgradable with 64 kB)
    • ROM: 96kB CMOS
  • Video: MOS Technology 8653
    • Modes:
      • 80 x 16 character location hires text mode in 2 colors (with a virtual screen of 80 x 25 character locations)
      • 480 x 128 hires bitmap mode in 2 colors
    • Although there was no external video output, Jeff Porter stated that "his team was thinking about a cartridge for the C=LCD which provided 80 column display for an external video display, using the C128's video chip"[3]
Original CLCD 80x16 character location display
Reconstructed CLCD 80x16 character location display

Chipset[edit | edit source]

Motherboard[edit | edit source]

Chipset of the CLCD Motherboard
PCB ID Type Manufacturer Code No Pins Remarks
U1 CPU Rockwell R65C102 40-pin DIP
U2 Gate Array MOS Technology 48-pin DIP Possibly Video Display Controller (VDC)
U3 Gate Array MOS Technology 48-pin DIP
U4 VIA Rockwell R65C22P2 40-pin DIP
U5 VIA Rockwell R65C22P2 40-pin DIP
U6 ACIA Rockwell R65C51P-1 28-pin DIP
U7 28-pin DIP
U8 OKI 16-pin DIP
U9 Texas Instruments 20-pin DIP
U11 6-pin DIP
U12 14-pin DIP
U13 Octal Buffer and Line Driver Texas Instruments SN74HC244N 20-pin DIP
U14 20-pin DIP
U15 20-pin DIP
U16 Char ROM 28-pin DIP
U17 Hex Schmitt Trigger Inverter Motorola MN74HC14N 14-pin DIP
U18 Programmable Quad Comparator National Semiconductor LP365N 16-pin DIP
U24 Quad 2-line Multiplexor Texas Instruments SN74HC157 16-pin DIP

Memory Daughterboard[edit | edit source]

Chipset of the CLCD Memory Daughterboard
PCB ID Type Manufacturer Code No Pins Remarks
U101 Texas Instruments 14-pin DIP
U102 ROM Mitsubishi M5M27C512AK-15 28-pin DIP
U103 ROM Mitsubishi M5M27C512AK-15 28-pin DIP
U105 ROM Mitsubishi M5M27C512AK-15 28-pin DIP
U105 ROM Mitsubishi M5M27C512AK-15 28-pin DIP
U106 ROM - 28-pin DIP Empty
U107 EPROM - 28-pin DIP Empty
U108 Texas Instruments 14-pin DIP
U109 RAM 28-pin DIP Expansion RAM
U110 RAM 28-pin DIP Expansion RAM
U111 RAM 28-pin DIP Expansion RAM
U112 RAM 28-pin DIP Expansion RAM
U113 RAM - 28-pin DIP Empty
U114 Texas Instruments 14-pin DIP
U115 RAM 28-pin DIP Built-In RAM
U116 RAM 28-pin DIP Built-In RAM
U117 RAM 28-pin DIP Built-In RAM
U118 RAM 28-pin DIP Built-In RAM
U119 28-pin DIP Spare

Software[edit | edit source]

The main menu offered a few utilities for copying from the internal RAM disk to an external drive, or for downloading over the built-in modem. On the ROM were a number of packages:

  • Wordprocessor: A fully-featured word processor with justification options, search phrases, headers and footers, underlined and in bold text, centering, cutting and pasting, and storage. Operates in split screen mode.
  • Spreadsheet: A-fully-featured spreadsheet similar to Microsoft's Multiplan.
  • Terminal: A telecoms package, which works with the built-in built-in 300bps auto answer/auto-dial modem. It can send and download files, it has a buffer interception and auto-managing by phonecall be associated with a built-in address book. All parameters can be modified. It can emulate both the DEC VT52 & VT100 terminals.
  • Memopad: A simple scratchpad program for making notes. It can be invoked while running other programs
  • Calculator: Can be run in business, scientific and programmable formats. It includes hex and binary mode. The program can be invoked while running other programs
  • BASIC: BASIC 3.6 is almost downward compatible with BASIC 7.0; however commands such as COLOR or system-specific POKEs will not work.
  • Monitor: A machine language monitor which is similar to that found on the Plus/4. The 65C102 has new addressing modes for ten 6502 instructions and eight new instructions[4]:
    • branch always (BRA)
    • command stack for the registers X and Y (PHX, PLX, PHY, PLY)
    • store zero in the memory (STZ)
    • testing, setting and resetting memory bits with battery (TRB, TSB)

Links[edit | edit source]

WP-W11.png Wikipedia: Commodore_LCD

References[edit | edit source]