Constructing and Installing an ACU (Adapter Card Unit) The following procedure explains how to build an ACU and add it to the IBM PS/1 2011 and 2121 model computers. IBM no longer manufactures the ACU as a complete option; however, you can purchase the seven snap-together parts to construct your own ACU from IBM's National Parts Center (1-800-388-7080.) The seven parts needed are as follows: 1383604- Adapter card (riser card) 1383605- Power card 1383610- Fan assembly 1383625- Adapter card base assembly 1383626- Adapter card unit cover 1383628- Power card guide and cover 1383632- Adapter card unit bezel To Assemble the ACU 1. Hold the adapter card base assembly so that the large rectangular opening is in the bottom, rear, left-hand corner. The front of the adapter card assembly should be bent upward with the small square opening in the center. 2. The power card guide is "L" shaped and attaches to the inside right rear of the adapter card base assembly. The short leg of the guide stands right and holds the rear of the adapter card. 3. The adapter card (riser card) is "T" shaped with two adapter card connector slots on the left and one on the right. Insert the card so the bottom of the "T" goes through the narrow, center, rectangular opening in the bottom of the adapter card base assembly. 4. Attach the rear of the adapter card to the power card guide and its front edge to the adapter card base assembly's center upright arm. 5. Insert the power card so that it fits into the power card guide and the small connector slot on the right rear of the adapter card. 6. Snap the power card cover into the power card and power card guide. 7. The fan assembly attaches to the small square opening in the front of the adapter card base assembly. Its power cable attaches to the lower, right-hand, front edge of the adapter card. To Install the ACU 1. Remove the bezel (face plate) and system cover from your PS/1 system unit. 2. Slide the new adapter card unit cover onto the PS/1 system unit. This will replace the PS/1 system unit cover you removed in the above step. 3. Align the ACU so it fits down over the four corner legs on the top of the adapter card unit cover (the ACU fan should face forward). The connector from the adapter card should fit through the narrow rectangular opening in the center of adapter card unit cover, and plug into J8 (adapter card connector) on the planar board (mother board.) 4. Carefully align the adapter card so it fits into connector (J8) on the planar board (mother board) and push down gently to seat the unit in place. 5. The PS/1 system unit and ACU are now ready for the addition of adapter cards (i.e., new high speed modems, game cards, and sound cards). 6. Once you have installed the new adapter cards, reinstall the original system cover on the adapter card base assembly. 7. Reinstall the PS/1 system unit's original bezel and install the adapter card unit bezel on the adapter card base assembly. For additional information on installing adapter cards (i.e., modems, sound cards, game cards) look in the Answer Bank under "Hardware and Accessories" "Grow the PS/1." If you have any questions about this procedure, please post a note in the appropriate topic or forum area.