D2CA.ORG - Dan's 20th Century Abandonware - Legacy Commodore Computer Hardware

D2CA's Legacy Commodore Computer Hardware

Note: The units featured below are a part of my vintage computer hardware collection and are not for sale at this time.

Commodore 64C

Year: 1986
Condition: Excellent
My Cost: US$2.00

Features:
- 2MHz 6510 CPU
- 64K RAM
- 6566/6567 (VIC II) video controller with 2048 bytes of video memory
- MOS 6581 Sound Interface Device synthesizer with 3 "voices"
- 1 user port
- 1 Datassette port
- 1 expansion port
- 1 RF port
- 1 video port
- 1 serial port
- 2 controller ports

Operating System:
- Commodore BASIC 2.0 interpreter

My Comments:
    This is a "second generation" Commodore 64. It can run application software on cartridges, cassettes, 5ź" floppy disks, print, and has a high-quality sound synthesizer that was ahead of its time.
    It can use either a Commodore computer monitor or a TV set for display, use Atari 2600 "joysticks" as "mice" as well as game controllers, and store data on ordinary audio cassettes using a Commodore cassette deck.
    This system was donated to D2CA by Stephen H. of Virginia USA. Thank you, Stephen!

Commodore 128

Year: 1985
Condition: Excellent
My Cost: US$2.00

Features:
- Commodore 128 and Commodore 64 modes
- 2MHz 6510 CPU (Commodore 64 mode)
- 2MHz 8502 CPU (Commodore 128 mode)
- 2MHz Z80 CPU (for CP/M)
- 128K RAM (upgradable to 512K)
- 40/80 column video
- 40-character 6566/6567 VIC II video controller
- 80-character 8563 video controller
- 2048 bytes of video memory
- Bitmap mode
- MOS 6581 Sound Interface Device synthesizer with 3 "voices"
- Machine language monitor
- Keyboard numeric keypad
- 1 RGBI video port
- 1 Commodore video port
- 1 user port
- 1 Datassette port
- 1 expansion port
- 1 RF port
- 1 serial port
- 2 controller ports
- Reset button

Operating System:
- Commodore BASIC 7.0 interpreter
- CP/M Plus 3.0 (Š 1982 Digital Research, Inc.)

My Comments:
    The Commodore 128 is actually 3 computers in one with separate CPUs for each operating mode -- Commodore 64, Commodore 128, and CP/M. This model is much more like a PC in that it can run the CP/M operating system and "boots" to the 5ź" floppy drive, and utilizes 80- character RGBI video. Commodore developed a 2-button mouse for the C128, but it will also accept Atari 2600 controllers like the C64. It will also run Commodore 1541 5ź" floppy drives as well as its 1571 model. It still has legacy support for RF TV video.
    If it only had a hard drive...
    This system was donated to D2CA by Stephen H. of Virginia USA. Thank you, Stephen!

Commodore C2N Cassette Unit

Year: 1984
Condition: Excellent
My Cost: US$4.00 (original: US$72.97)

Features:
- Uses standard analog audio cassette tapes for recording data
- Commodore proprietary data format (TTL logic-level shifts) using pulse-width modulation and square waves that allows for file and
    program naming, verification of programs and end of tape marker sensing
- Write/record amplifier converts data sent from the computer (TTL logic-level shifts) using a pre-amplifier and a power amplifier to
    an output current then sends it to the read/write head, producing magnetic fields representing the data onto a magnetic tape.
- Read/playback amplifier reads previously recorded magnetic fields representing computer data on a magnetic tape and converts
    them to computer data (TTL logic-level shifts) by means of an amplifier limiter removing amplitude variations and a switching
    circuit which toggles output data between 0 and 5 volts (machine language 0's & 1's) then transmits the data to the computer.
- 300 baud throughput
- Programs saved twice for internal error checking
- Data file checksumming
- Software detection key press sensor
- Auto stop
- Hardware RECORD, PLAY, REWIND, FFWD, STOP and EJECT buttons
- Cassette tape counter

My Comments:
    And you thought it was easy for information to be encoded and transmitted from a computer to an audio cassette tape and back again? This isn't like recording A Flock of Seagulls from a vinyl LP album.
    But while all this technobabble may sound impressive, the time it takes for the data to be recorded onto a cassette tape and the time it takes to transfer data from a cassette tape is incredibly slow. 300 baud is a fraction of today's 56K baud modem dial-up Internet speed. A 16K program -- only one of the four memory address segments in a Commodore 64 -- can take over 45 minutes to load into the computer from a cassette tape. Consider if you had a program of such size that it required all four linked memory segments of a Commodore 64 to load. You could wait over 3 hours for that single program to load -- before being able to use it.
    But, to the C2N Cassette Unit's credit, this was, in fact, a brilliant move by Commodore and other computer companies to offer people a low-cost storage solution for their programs and data. The Commodore VIC-20, Commodore 64 and Commodore 128 did not have a hard drive or built-in floppy disk drive. Data storage/retrieval hardware had to be purchased separately as external add- on peripherals. In the early 1980's it was difficult for the average home computer user to afford the US$375.00 Commodore 1541 5ź" floppy disk drive, much less the single-sided 5ź" floppy disks they required. At US$72.97, the C2N Cassette Unit was a more cost-efficient storage solution which could use off-the-shelf blank analog audio cassettes to store and retrieve information.
    I also have a second Commodore Datassette tape unit that is nearly identical in design to the C2N Cassette Unit which I acquired for US$14.00.

Commodore 1541 5ź" Floppy Disk Drive

Year: 1982
Condition: Excellent
My Cost: US$210.00 (4 units, original: US$1,500.00)

Features:
- Single-sided 165K disk capacity (formatted, 170K unformatted)
- 144 files limit per floppy disk
- 6502 CPU
- 2 6522 I/O Versatile Interface Adapters and internal I/O timers
- 16K ROM containing the internal DOS 2A
- 2K 6166 RAM buffer
- 2 serial ports
- Ability to "daisy-chain" up to four 1541 floppy drives and one printer

My Comments:
    This 5ź" floppy drive can be used on VIC-20, Commodore 64 and Commodore 128 computer systems.
    Dan's 20th Century Abandonware currently uses a Commodore 1541-N floppy drive for creating D64 disk images. The advantage to this drive is it uses a standard power cord and does not require a proprietary adapter.
    If a drive or a power unit fails, a drive from another 1541 can be exchanged with relatively little effort. I have created one working 1541 drive from two faulty 1541 drives -- one with a good drive and a bad power supply, the other with a good power supply and a bad drive. By replacing the bad drive in the unit with the good power supply with the good drive from the unit with the bad power supply I was able to produce one working drive where two bad drives existed previously.
    D2CA has three Commodore 1541 and one Commodore 1541-N 5ź" floppy drives.
    One Commodore 1541 5ź" floppy drive was donated by Stephen H. of Virginia USA. Thank you, Stephen!

Commodore 1541-II 5ź" Floppy Disk Drive

Year: 1986
Condition: Excellent
My Cost: US$136.00 (3 units, original: US$1,125.00)

Features:
- Single-sided 165K disk capacity (formatted, 170K unformatted)
- 144 files limit per floppy disk
- 6502 CPU
- 2 6522 I/O Versatile Interface Adapters and internal I/O timers
- 16K ROM containing the internal DOS 2A
- 2K 6166 RAM buffer
- 2 serial ports
- Ability to "daisy-chain" up to four 1541-II floppy drives and one printer

My Comments:
    This 5ź" floppy drive can be used on VIC-20, Commodore 64 and Commodore 128 computer systems.
    Dan's 20th Century Abandonware currently uses two Commodore 1541-II floppy drives with the Commodore 128 system (above). The advantage of the 1541-II drives is they have built-in dip switches to change the device number. This eliminates the need to physically alter older 1541 drives or "softwire" two drives for data exchange. They also have a faster data transfer rate.
    One of the drives I purchased also came with a colorful dust cover.
    D2CA currently has three 1541-II units.

Commodore 1084S Computer Monitor

Year: 1988
Condition: Excellent
My Cost: US$2.00

Features:
- 13" viewing screen
- 40-charcter color/monochrome resolution
- Audio speaker
- Hue, brightness, contrast, color, sharpness, volume controls
- Composite-separated LCA / RGB selector
- Composite (NTSC) / Separated Luma-Chroma-Audio switch
- CVBS/L phono, 3 Chroma, 1 Audio jacks
- Left/Right phono jacks for Amiga systems
- TTL RGB, LIN.RGB connectors
- VCR switch
- Vertical height, vertical center, horizontal width, horizontal center controls

My Comments:
This monitor is used for the Commodore 64C and Commodore 128 systems above.
This unit was donated to D2CA by Stephen H. of Virginia USA. Thank you, Stephen!

Commodore MPS-801 Dot-Matrix Printer

Year: 1983
Condition: Excellent
My Cost: US$2.00

Features:
- 6x7 character dot-matrix, 80 columns per row
- Graphics mode 7 vertical dots per column, 480 columns per row
- CPM ASCII Code character set
- 50 characters/sec. printer speed, 10 characters/in. spacing
- 6 lines/in. character mode, 9 lines/in. graphics mode
- 5 linefeeds/sec.
- Self-diagnostics/test pattern
- Tractor paper feeder
- 2 I/O connector ports

My Comments:
This printer is used for the Commodore 64C and Commodore 128 systems above.
This unit was donated to D2CA by Stephen H. of Virginia USA. Thank you, Stephen!

Atari 2600 Joystick Controller

Year: 1978
Condition: Excellent
My Cost: US$20.00 (4 controllers)

Features:
- 360-degree joystick motion
- Tactile "fire" button

My Comments:
This controller is used as a "mouse" and game controller for the Commodore 64C and Commodore 128 systems above.