Vintage IBM Mainframes Do IT 24/7 Graphic T-Shirt Vintage IBM Mainframes Do IT 24/7 Graphic T-Shirt Size: M Authentic vintage IBM tech promo t-shirt featuring a "Mainframes do IT 24/7" center graphic and sleeve logo. Classic regular fit cut from 100% heavy cotton Gildan Ultra Cotton fabric. Perfect Y2K era streetwear piece for collectors of corporate and computer history. #vintage #ibm #tech #streetwear #y2k