C64 Direct-to-TV

The C64 Direct-to-TV, called C64DTV for short, is a single-chip implementation of the Commodore 64 computer, contained in a joystick with 30 built-in games. The design is similar to the Atari Classics 10-in-1 TV Game. The circuitry of the C64DTV was designed by Jeri Ellsworth, a self-taught computer chip designer who had formerly designed the C-One.

Tulip Computers (which had acquired the Commodore brand name in 1997) licensed the rights to Ironstone Partners, which cooperated with DC Studios, Mammoth Toys, and in the development and marketing of the unit. [ [http://www.gamesindustry.biz/content_page.php?aid=7104 The Commodore 64 bounces back to life as a Direct-To-TV plug and play Joystick! // GamesIndustry.biz ] ] QVC purchased the entire first production run of 250,000 units and sold 70,000 of them the first day they were offered. Coincidentally, QVC's West Chester, Pennsylvania Studio Park headquarters once were Commodore's offices.

Versions

There exist multiple versions of the C64DTV. DTV1 (NTSC television type) comes with 2 MB ROM. It first appeared in late 2004 for the American/Canadian market. DTV2 (called "C64D2TV" sometimes) is a revised version for the European and world markets (PAL television type) and appeared in late 2005. The ROM has been replaced by flash memory in these devices. Unfortunately the DTV2/PAL version suffers from a manufacturing fault, which results in poor colour rendering (the resistors in the R/2R ladder DACs for both the chroma and the luma have been transposed). In the DTV3, a problem with the blitter was fixed. Another DTV variant is the Radio Shack "HUMMER Off-Road Racing Challenge Video Game". [ [http://www.radioshack.com/product/index.jsp?productId=2143057 RadioShack.com ] ]

Hardware Specifications

* Core circuity
** ASIC running at 32 MHz internally, emulating 6510 CPU, VIC-II, SID, CIA, and PLA
* Casing/Connectors
** integrated in a Joystick (as if connected to port 2 of a real C64)
** five additional buttons (acting like keys)
** running from batteries only (four AA batteries)
** Composite Video, monaural audio (RCA connectors)
** looks similar to a "Competition Pro" joystick
* Graphics
** NTSC (DTV2 and later: NTSC/PAL on chip, only PAL wired in end-market devices)
** reprogrammable palette with 4 bits of luma and 4 bits of chroma
** DTV2 and later: "chunky" 256 color mode, additional blitter for fast image transformation
* Sound
** no support for SID filters
** DTV2 and later: 8 bit digital sound, additional options for envelope generators
* Memory
** DTV1: 128 KB (KiB) RAM, 2 MB ROM
** DTV2 and later: 2 MB RAM, 2 MB flash memory
** DMA engine for RAM/RAM and ROM/RAM memory transfers
** DTV2 and later: additional RAM access using bank switching and blitter
* CPU
** emulating a 6510 at 1 MHz
** DTV2 and later: Enhanced CPU (fast/burst mode, additional registers and opcodes, support for illegal ops of the 6510)

Built-in games

The official games for the unit are mostly a mix of Epyx and Hewson C64 games. This list is valid for the NTSC version.

EPYX

* "Summer Games I"
* "Winter Games I"
* "Pitstop I"
* "Pitstop II"
* "Supercycle"
* "Jumpman Jr."
* "Impossible Mission"
* "Impossible Mission II"
* "Championship Wrestling"
* "Gateway to Apshai"
* "Sword of Fargoal"
* "Silicon Warrior"
* "World Karate Champion" (AKA "World Karate Championship"/"International Karate")
* Several events taken from Epyx "Games" series, including "Bull Riding", "Sumo Wrestling", "Flying Disks"

Hewson

* "Tower Toppler" (AKA "Nebulus")
* "Paradroid"
* "Eliminator"
* "Cyberdyne Warrior"
* "Cybernoid I"
* "Cybernoid II"
* "Ranarama"
* "Firelord"
* "Exolon"
* "Uridium"
* "Zynaps"

Image Works

* "Speedball"

Hardware-modding

Since the internal circuit board has exposed solder points for floppy-drive and keyboard ports, hardware modifications of the C64DTV are quite simple.

Known hardware mods
* keyboard connector
* external joystick (Port 1 and 2)
* floppy connector
* power unit connector
* fixing the palette problems of the PAL version (to some degree this is possible in software by adjusting palette entries)
* S-Video connector
* user port
* Original C64 casing and PS2 keyboard [ [http://joco.homeserver.hu/mmc2iecKB/ C64DTV in original C64 case ] ] Additional hardware
* Data transfer cable (Parallel port (or USB/serial port via DTV2ser) to Joystick or user port)
* SD card interface "1541-III" or "MMC2IEC"

The board could be used as a System-on-a-chip (SoC) embedded computer for control applications.

Limitations

The internal flash memory is accessible as device 1. However, software is not included to support write operations so high score saving is not possible. Also, flash devices used in the DTV are specified for a very limited number of write accesses only.

oftware-modding

The DTV contains software-flashable memory. A number of tools have been released to compile programs into a DTV-compatible flash images and load it onto the DTV. People made their own game compilations, adding popular (sometimes DTV-fixed) games that were not in the original DTV, added boot menus to make homebrew software development easier or enable new features, for example transfer programs like DTVtrans for transferring data from PC to DTV RAM and vice versa via the PC parallel port (or USB) and the DTV joystick port.

References

External links

* [http://picobay.com/dtv_wiki/ DTV Hacking Wiki] - DTV versions overview, HOWTOs, DTV Programming guide
* [http://viceplus.sourceforge.net/ VICEplus] - fork of the VICE Commodore emulator including C64DTV support
* [http://www.c64dtv.co.uk The Official C64 DTV site] - user manual plus some other information
* [http://galaxy22.dyndns.org/dtv/ David Murray's Commodore DTV Hacking]
* [http://www.kahlin.net/daniel/dtv/ C64DTV stuff by tlr] Flash Tool, ML-Monitor, PC<->DTV transfer system
* [http://www.geocities.com/dtvhacking/ Mr. Latch-up's C64 DTV & Hummer Advice Column]
* [http://home.wanadoo.nl/richard.lagendijk/Pagina/INFO-DTV-GB.htm A page about the history of the device]
* [http://www.kahlin.net/daniel/dtv/colorfix.php Details on fixing colour problem on PAL DTVs] - Note that surface-mount soldering skills are required.
* [http://www.kahlin.net/daniel/dtv/cable.php DTVtrans, connecting a DTV to a PC via parallel port]
* [http://lallafa.de/blog/index.php/dtv2ser/ DTV2ser, connecting a DTV to a PC/Mac via USB or serial port]
* [http://www.xs4all.nl/~lagendr/Pagina/COMP-C64-DTV2.htm Four ways to turn a C64 DTV into a C64 clone]