now you got me thinking, Zane. I have FIS in my 11/44, and I am not sure I have CIS either installed in the /44, or the module is somewhere, or I passed on it for the same reason I did not install the CIS chip in the QBUS-based 11. My 11/35 OTOH does have FIS and CIS (and MMU plus SLR), but that's just to have a complete CPU with *all* options :-) - Henk. ________________________________ Van: cctalk-bounces at classiccmp.org namens Zane H. Healy Verzonden: vr 10-02-2006 20:27 Aan: cctalk at classiccmp.org Onderwerp: Re: What's CIS for? (was RE: Original 11/74 front panel) As I recall, it's for *business* computing, rather than *scientific* computing. I think it speeds up Cobol, and maybe some other stuff. Out of *all* of my PDP-11's, the only system I have with the CIS option is a /23+. I rather wish I had it for my /44, though I don't actually need it :^) Zane This message and attachment(s) are intended solely for the use of the addressee and may contain information that is privileged, confidential or otherwise exempt from disclosure under applicable law. If you are not the intended recipient or agent thereof responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, please notify the sender immediately by telephone and with a "reply" message. Thank you for your cooperation.