Hello to all, frankly I think I'm in a loop. Let's see the summary . Ultimate goal : to install a Compact Flash card <http://www.memoryc.com/images/products/b/adata-2gb-cfc-speedy_4711.JPG> http://www.memoryc.com/images/products/b/adata-2gb-cfc-speedy_4711.JPG on a cf- ide adapter <http://img.dxcdn.com/productimages/sku_0711_1.jpg> http://img.dxcdn.com/productimages/sku_0711_1.jpg on a controller PTI- 227B V2 <http://www.rainbow-software.org/manuals/pti-227b.html> http://www.rainbow-software.org/manuals/pti-227b.html into an IBM PC AT 286 5170 <http://www.vintagesbc.it/?page_id=838&gtlang=en> http://www.vintagesbc.it/?page_id=838&gtlang=en Not being sure of anything I have designed different steps. I ask for help for the first one that is : Make sure that the Compact Flash <http://www.memoryc.com/images/products/b/adata-2gb-cfc-speedy_4711.JPG> http://www.memoryc.com/images/products/b/adata-2gb-cfc-speedy_4711.JPG on a cf- ide adapter <http://img.dxcdn.com/productimages/sku_0711_1.jpg> http://img.dxcdn.com/productimages/sku_0711_1.jpg to boot on an old PIII PC <http://it.gigabyte.com/products/mb/specs/ga-6vxc7-4x.html> http://it.gigabyte.com/products/mb/specs/ga-6vxc7-4x.html that I normally use to transfer files between different diskette's formats and disk that has as OS Windows 98 and its relative DOS . I can also load on it a DOS 3.3 , and so on. If this works I will can try the union of CF + adapter + controller on the same PC and then follow again all into the IBM PC 286 . I premise that the PIII's bios made available to me to set the automatic recognition of geometry of the HD connected once and forever to be sure to not have discrepancies for HD and even for the Compact flash card at each turn on of the computer. Anyway from its bios I can always choose from which drive to boot from . Yesterday , I took an old IDE 6GB HD , I partitioned it to 2GB with a DOS3.3 ( with FDISK first and then with format / s ) so I launched Acronis CD to make a clone of the HD partition on the compact flash . It took a bit to do this perhaps to resize the copy . At the end , however, the boot did not work the same. It was the last attempt after days of testing . Imagining that on a compact flash perhaps the BOOT sector might be seen differently (being theoretically removable) compared to HD . I found an interesting document <http://thestarman.narod.ru/asm/mbr/STDMBR.htm#CHS> http://thestarman.narod.ru/asm/mbr/STDMBR.htm#CHS but it is too complicated for me . I thank you for all your straight. Otherwise, I give up . Enrico