Release 6.3i - Promgen G.35
Copyright (c) 1995-2004 Xilinx, Inc.  All rights reserved.
0x72864 (469092) bytes loaded up from 0x0
Using generated prom size of 512K
Writing file "now_this.mcs".
Writing file "now_this.prm".

PROMGEN: Xilinx Prom Generator G.35
Copyright (c) 1995-2004 Xilinx, Inc.  All rights reserved.

promgen -p mcs -w -o now_this.mcs -u 0 now_this.bit 

PROM now_this.prm map: Fri Mar  9 16:36:41 2012

Format        Mcs86 (32-bit)
Size          512K
PROM start    0000:0000
PROM end      0007:ffff

        Addr1        Addr2 File(s)
    0000:0000    0007:2863 now_this.bit