Hi Olivier, Thanks for your help. I downloaded the 'prol' program that you showed to me. I ran it on a rules file that i created using included samples as a guide. The program created a '.rds' file that i subsequently used with 's2r.' 's2r' complained initially that it had encountered an unexpected 'eof' and that there were missing definitions. Subsequent comparison of the new '.rds' file and cmos_7.rds showed that there were in fact portions of file that apparently were not created by the 'prol' program. I suspect that the missing elements are required for features that were added after the 'prol' program was written and that this is probably the reason that 'prol' is obsolete.... I then copied what appeared to be the missing parts of the file from 'cmos_7.rds' to the new '.rds' file. 's2r' now reads the new '.rds' file up to the DESIGN_RULE section at which time the program exits with a 'syntax error.' I can no obvious syntax error. Is there any documentation that specifies the required elements of the technology file? By the way, I have looked through the 'search' section of the alliance web page where i found lots of interesting information, but nothing that helps with this problem. Thanks in advance for your help. Sincerely, Ken Spicer spicer@atmel.com