DVI specification was officially released in April 1999. So only cards released after April 1999 can have DVI. It is worth to know that sometimes card's manufacturers were adding DVI to GPUs released before year 1999. The oldest one I found is Riva TNT2 from Creative. It is just a matter of sticking TMDS chip to the board and you can make most of 1998 cards DVI capable. GPU chip needs only to provide I2C video output on its pins to connect TMDS DVI transmitter chip. The only company at that time making TMDS chips was Silicon Image. On some cards DVI needs some activation tool to make it working so beware in DOS because since a long time manufacturers do not provide DOS tools.
Remember that card having DVI connector may not support digital signal but pure analog only.
DVI-I is analog + digital
DVI-A is analog only
DVI-D is digital only
http://en.wikipedia.org/wiki/DVI
There are also some industrial connectors who look like DVI but are not DVI:
http://en.wikipedia.org/wiki/DMS-59
http://en.wikipedia.org/wiki/Low_Force_Helix
They may have digital DVI signal but not for sure. For sure they need special cable with DVI-D on one end and provide DVI-D signal to make LCD panels working with such card.
If you are looking now for Geforce/Riva cards on PCI bus there are very easy to find because Riva TNT/Geforce 2 MX or other old GPUs are still manufactured in small quantities for Industry needs (their PCs have only PCI bus) and have DMS-59 or LFH connector.