"ADDCARD" as advertised in PCM and 80-Micro by Discount Computer Supplies looks to be exactly what we original T1K(A)'ers need to expand our lowly three slot machines... The board (costing $99 not $79 as advertised on one of the mentioned magazines) is a little over 3.5 x 8.5 inches and simply plugs into "the slot nearest the disk drives" once you have mounted all the 8" or shorter boards on the ADDCARD board. It also mentions in the instructions that you may, (read that have to) remove the metal tab mount from the card before inserting it into the ADDCARD board. The slots on the board are spaced 0.75" inches apart, providing for a tight fit for some boards. My first problem was trying to mount a stock Tandy RS232 card onto the ADD- A-SLOT board. After removing the metal tab, plugging in the board, and "eyeballing" the fit into my stock 1000HD, i noted the metal cage around the fan and the power supply (something lacking from my early 1000) butted right up against the 25pin connector for the RS232 card eliminating the possibility of plugging a cable onto it. The second problem was the major one with me. After mounting the hard drive controller card onto the ADDCARD board, and plugging it in. My T1000HD failed to recognize the hard drive no matter the slot used on the ADDCARD board. Granted the controller card could be moved to the middle slot, but it would be necessary to make (or have made) special cables rerouting around the ADDCARD board which has to reside in the slot closest to the disk drive(s). It was at this point that I packed up the ADDCARD board and am returning it to the distributor. My impression of the board itself is it's pricey. For $99+ you're getting little more than a piece of circuit board with 4 female and 1 male connector, a metal tab (incidentally not compatible with the T1K's back mount), and a very simple trace pattern connecting the connectors. T1000HD owners also note the placement of your hard drive makes the lowest slot on the board unusable unless you have a VERY-short board to install. The board probably performs quite well as long as you have cards to install on it that fit the parameters of the space you have available. I just gave up on both ADDCARD and this review when I found the my stock Tandy hard drive controller card would not work when installed in ADDCARD.