CDTV

In 1991 March Commodore released its first CD console, the CDTV (Commodore Dynamic Total Vision). This console was designed around A500 and some components of the A2091 SCSI controller and came in standard 43 cm HiFi format. The CDTV has anticipated many modern design concepts like the integrated CD-ROM drive.

Processor

68000 @ 7-14 MHz
68020 @ 14-33 MHz
68030 @ 16-50 MHz

All CDTVs have a socketed 68000 @ 7.14 MHz on their motherboard. Upgrading the processor requires the use of an accelerator board attached to the 68000 socket - many of those A500 internal accelerators fit inside the CDTV.

Memory

up to 2 MB Chip RAM
up to 32 MB Fast RAM on processor boards
up to 8 MB Fast RAM on expansion cards attaching to the diagnostic port
up to 256 kB on proprietary memory cards

The CDTV has 8 ZIP sockets on its motherboard, which take 256k×4 ZIPs giving 1 MB Chip RAM in total. Chip RAM can be expanded to 2 MB with third party expansions which replace the Agnus chip.
Internal expansion cards, which connect to the diagnostic connector, allow the addition of up to 8 MB 16 bit Fast RAM. Processor cards featuring a 68020 or better may add up to 32 MB 32 bit Fast RAM. The special CDTV memory cards can be used as RAM expansion increasing the RAM amount by 64 or 256 kB.

Custom chips

Fat Agnus - display controller
Denise - display encoder
Paula - audio and I/O controller
Gary - system address decoder
DMAC - DMA controller
(6525) - CD-ROM controller
(6554) - front panel controller
(6500) - keyboard controller
CIA - complex interface adaptor

Supported screen modes
LowHigh
PAL non-interlaced
PAL interlaced
NTSC non-interlaced
NTSC interlaced
320×256
320×512
320×200
320×400
640×256
640×512
640×200
640×400
50 Hz, 15.60 kHz
50 Hz, 15.60 kHz
60 Hz, 15.72 kHz
60 Hz, 15.72 kHz
Supported palettes
LowHigh
32 / 4096
64 (EHB)
4096 (HAM)
16 / 4096

The LC6554H microcontroller drives the LCD display on the front panel, handles the buttons and the infrared port. It communicates with the rest of the system through the 6500/1 microcontroller chip.
All CDTVs shipped with Kickstart 1.3 ROMs. Upgrading to Kickstart versions above 1.3 is only possible with special hardware released by third party manufacturers.

Expansion slots

1× diagnostic slot
1× DMA expansion slot
1× proprietary memory card slot
1× video slot

The 80 pin diagnostic slot offers nearly the same signals as the A500's side expansion connector, it is meant for any type of expansion device.
The 30 pin expansion slot can be used for DMA expansions, e.g. SCSI controllers.
The proprietary memory card slot (40 pins) takes memory cards of 64 kB or 256 kB size. These cards can be used as RAM expansion or flash memory; the content is battery backed up.
The 30 pin Video Slot is occupied by the video module, but this unit can be replaced by other expansion devices.

Look up the CDTV expansions from the database.

CD-ROM drive

The CDTV features a single speed (153 kB/sec) caddy loading CD-ROM drive. The supported CD formats are ISO-9660 CD-ROM, Audio CD, CD+G and CD+MIDI.
CD+G is a special Audio CD containig low resolution still images. CD+MIDI has MIDI tracks encoded along with the CD audio portion, allowing to play along with a synthesizer attached to the CDTV MIDI ports.

Interfaces

1× serial DB25 male, RS232
1× parallel DB25 female, Centronics
1× video DB23 male, analog RGB
2× mouse/game, 5 pin DIN female
2× stereo audio, RCA jack
1× external floppy DB23 female
1× keyboard, 6 pin female mini-DIN
1× MIDI In, 5 pin DIN female
1× MIDI Out, 5 pin DIN female
1× IR port
1× 6.3 mm stereo headphones jack
1× 40 pin CD-ROM header
UK version
1× S-VHF
1× composite video, RCA jack
USA / Canadian version
1× RF In
1× RF Out
1× composite video, RCA jack
European version
1× Scart (CD1321 video module)

All the video connectors (except the RGB port) belong to a removable video module, thus enabling different configurations for different countries. The module is much the same like an internal A520.
The floppy drive controller supports up to four devices, all connected externally.
The CD-ROM interface is a crippled SCSI-I connector and needs a special CD-ROM drive connected to it.
The MIDI ports are a part of the standard serial port circuitry. The CDTV can use either a serial device or a MIDI device, but not both at the same time.

Motherboard revisions

revision 2.1
revision 2.2
revision 2.2.1 (Photo)
revision 2.3

Other components

clock - front panel time display
keys on the front panel to control the CD player
Power and CD drive LEDs
infrared remote controller