It features a 10 MB hard drive, 8 MHz Intel 80286 CPU and a black & orange 9.5" gas-plasma display with a resolution of 640 × 400 pixels.

[2] The portable has a special high-resolution 640 × 400 display mode which is similar to and partially compatible with the Olivetti/AT&T 6300 graphics.

There is a single proprietary expansion slot for 1200 bit/s modem, expansion chassis for 5x 8-bit ISA cards, Ethernet NIC, 2400 bit/s modem, and a 2 MB memory card (thus 2.6 MB in max total).

[3][4] Toshiba T3100 is not a true portable, because it needs an external power source in all except the last version.

Five versions exist: BYTE in 1989 listed the T3100/20 as among the "Distinction" winners of the BYTE Awards, citing its "amazingly clear" display and hard drive.