See my comments marked <**> below Bob Ammerman RAm Systems (high performance, high function, low-level software) ----- Original Message ----- From: Dale Botkin To: Sent: Thursday, June 15, 2000 10:47 AM Subject: Re: [PIC] How about an open-source emWare like product? > On Thu, 15 Jun 2000, Bob Ammerman wrote: > > > What do you PIClisters think of setting up some sort of open-source project > > to build an emWare like enivoronment? > > I'd go along with the "direct to Net" group on this one. While it's > painfully true that it is not practical to put the entire RFC-compliant > stack in a PIC, I think we could get an acceptable subset working in a > relatively small codespace. <**> I think there are probably applications for both 'direct to Net' and 'gateway supported' connectivity. > TCP is complex, and I'm working now to determine exactly what *has* to be > done as opposed to what we'd like to see. ICMP is a slam-dunk, UDP isn't > difficult at all, IP is dead simple, and SLIP is child's play. I've even > got two different methods of the device determining its own IP address. > One takes more space and is "cleaner" but depends on a particular sequence > of events from the other end of the SLIP connection. The other is slimy, > low-down and dirty, but takes nearly no code and will work just fine. My > point is that SLIP is a whole lot more compact than PPP and can work just > as well. <**> One of the biggest problems with the minimal implementations is that they tend to not have proper error recovery. This is because they don't have the space (RAM) to store enough state, nor the space (ROM) for all the error handling code. This means that they seem to work when everything is clean and happy around them, but break down quickly once things start going wrong.