<There are a few good tricks to get PDP11 with odd configurations to load. T Boots for this list were found in the RT11 pocket guide, the longest was 31words. Most about 20. rx01 rx02 tm11 tju16 rp02/3 rjs03/4 rk11 rf11 dectape(tu60) dectapeII(tu58) RL01/2 Rk06 <first is the venerable paper tape bootstrap. It consists of only 8 instruct <(28 bytes) and works on serial ports. It then loads the 'absolute loader' The tu58 is also short and can load any program with code in block 0 (default boot block). the tu58 can also simulate a console driving ODT. The best part if TU58 is serial interface and can be hooked up to any unix/linux/dos/cpm/Whatever box that has a serial port. <On the subject of bad blocks, V6 and V7 offered no bad block strategies. <The DEC spec for RK05's was 200 tracks by 12 sectors by 2 surface plus 3 <bad block tracks for 4800 blocks plus 72 spare. The media was generally pre <good, and all Unix versions used 4872 block filesystems. the above describes a strategy. Well, transparent or system based the blocks are allocated. CP/M does not do block replacement but utilities can mark bad blocks by allocating them, or revector them at the hardware level. I believe mkfs does this. Some disks like the RQDXn do this at the hardware level. Allison