Uh oh, Dan, we agree again. As to Bob's "two boxes" and "power supply" I suggest that you get one bigger box, bolt the external modem into it, and bolt the application board somwhere else in the box. Or maybe inside the modem, if there's room. The power can be handled smartly by having the input jack from the wall wart plug into the application board, which then draws its power from it and passes the rest on to the modem. If the original wall wart is incapable of supplying adequate power, just get a bigger one instead. Or you could charge a (internal) battery and let the modem draw power from there when it needs to run the modem. The modem, after all, only needs power when it's in use. Andy Dan Michaels on 10/30/2000 02:39:43 PM Please respond to pic microcontroller discussion list To: PICLIST@MITVMA.MIT.EDU cc: (bcc: Andrew Kunz/TDI_NOTES) Subject: Re: [PIC]: Modem suggestions Bob Ammerman wrote: >Negatives for external modems: > >-Size >-Power supply >-Two boxes >-"clunkiness" >-Room for end users to goof things up >-Cost > Negatives for internal modems: -Size -Power supply -Two pcbs wired together -"awkwardness" -Pain-ina-butt interfacing to PCI or ISA bus -Writing modem-specific s.w. -Cost [cheap - only advantage I can see] Negatives for integrating chip modems: -Finding a chip <= 64-pin smt -Writing "all" the s.w. -Designing complex multi-layer pcb -Designing complex analog-digital-filtering ckt -Integrating DAA -Getting FCC approval -Cost [chips ain't cheap in < 100,000 qty] -Cost [prohibitive when using available DAA modules] Seems every route has its own personal set of problems. - danM -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics