IBM yesterday trickled out a number of software enhancements for the RT Personal Computer, notably software emulation of MS-DOS, and added four mainframe printers including a 3800 that uses a Kodak engine and can use cut sheet paper. The AIX/RT Personal Computer AT simulator is a $500 program due June that runs multiple real-mode PC-DOS 3.3 sessions concurrent with AIX sessions, and the facility to exchange files between the two. X Window 2.1 will be out September. Samna Plus IV for the RT arrives April at $700 single user, $2,000 multiuser. A 6156 Portable Disk Drive, 114Mb per module costs $4,600 plus $850 for the adaptor, from June, or $5,100 in a three-module housing modules $3,900 apiece. New 2.2 releases of AIX/RT and Virtual Resource Manager are $2,300 and $895. The 92 page-per-minute IBM 3827 cut sheet duplex – Kodak – printer at $185,000 arrives in May, and the 3835, 88ppm, takes fanfold paper up to 15 wide at $135,000 from mid-year.