Actually, it turns out that that's not quite true. We heard some of the history of the 1800's development from Neil Hillier, this 1800's former owner. He was on the design team. While the 1800 has the same instruction set as the 1130, the CPU's hardware design was done by a different team to meet different performance goals, and thus the implementation is not the same. We're hoping to give Neil a formal and thorough grilling, er, interview for ibm1130.org after he's finished his move to Montana. Brian =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- _| _| _| Brian Knittel _| _| _| Quarterbyte Systems, Inc. _| _| _| Tel: 1-510-559-7930 _| _| _| Fax: 1-510-525-6889 _| _| _| Email: brian at quarterbyte.com _| _| _| http://www.quarterbyte.com