Dreamcast:Dreamcast Model Differences
Page content & researching taken from io55.net's Dreamcast page with permission, in collaboration.
There is only 1 model of the Dreamcast, but 3 revisions within it.
Models + Revisions
Models are arranged chronologically. Revisions are underneath their respective model.
“Dreamcast” (1999-2001)
The only model of this console. Up front are 4 controller ports, while the top has the drive, plus on/off & open drive buttons. The left side has nothing, and the right side has the large extension port, by default taken up by the Dreamcast’s 56k modem (which is removable). On the back is the AC out (same plug as Model 2 Saturns), plus AV out, the line/Ethernet port (depending on peripheral in EXT), and a serial port meant for link cables. There’s nothing on the bottom. Later revisions have a supposedly better drive, but to the detriment of installing certain ODEs. All Dreamcasts have certain issues between the PSU-board connection, but this can be fixed with just a clean, or a soldering/replacement job.
“VA0” (very early 1999)
These systems can be hard to find in America, and are definitely more common in Japan. Here, the motherboard runs hotter, warranting a more robust cooling solution. Furthermore, chips in the system that the GDEMU ODE uses, output a hazardous voltage level. This can damage the GDEMU install if not taken into account. For this reason, be wary of these systems. However, some say they have a superior build quality. To identify, go to the bottom of the system; look for the “0” in the circle, to the left of the [NTSC | U] box on the sticker.
“VA1” (1999-2000)
A vast majority of NTSC-U Dreamcasts are of the VA1 revision. These can play burned discs, and can support an install of GDEMU. To identify, go to the bottom; look for the circled “1”, next to the NTSC-U code.
“VA2” (2001, to 31st March)
Quite rare, but not as rare as the VA0s, although this is not confirmed. Here, the drive controller is now integrated with the board itself. As of 2022 there is no GD-ROM emulator replacement for the VA2 models. Furthermore, the drive does not support playing burned discs. To identify, go to the bottom, look for the circled “2” next to the NTSC-U code.
References
https://dreamcast.wiki/MIL-CD_compatibility
https://www.reddit.com/r/dreamcast/comments/lfhr2z/great_dreamcast_hardware_revision_database/
https://www.reddit.com/r/dreamcast/comments/8zaxni/i_just_found_a_rev_0_ive_read_this_is_the_best/
https://gdemu.wordpress.com/details/dreamcast-details/
https://gametrog.com/sega-dreamcast-information-specs/
http://www.tankgirl.info/8bit/images/sega/dreamcast/modem.jpg (removed modem, reveals EXT)
https://cdn.shopify.com/s/files/1/0049/8719/1386/products/image_ed7b0f8a-d94a-4749-9ca9-cca916f238f8_500x205.png (sticker on the bottom, showing the circled number for revision)