On 03/04/2013 09:56 PM, Yaro Kasear wrote:
Here is part of a netlist for a device made in microstrip , designed to work at 1296MHz (1.296GHz) The device is made on a substrate which is 60 mil thick with a relative dielectric constant of 4.2. It consists of one input line (1 to 2) two lines coming off the end of that line (2 to3 and 2 to 5) the length (l1) and width (w1) of them to be determined by the program, a resistor between the far ends of those lines, i.e., between nodes 3 and 5, of 100 ohms, and two output lines, one from 3 to 4, one from 5 to 6. This device is called a Wilkinson hybrid. The program will go on to specify the impedance match at each port, the isolation between ports 4 and 6, and will measure the loss from port 1 to port 4. If any of the specifications are not met, the program sill still attempt to meet the requirements, and determine what the best solution is, and print out the results. The variables and their limits would be defined in real life, but are omitted here, as are the isolation value and the thru loss. To draw this graphically, per HP, each line would have all the parameters, including the substrate, listed next to it's picture. The design would take up about 2½ x 5 inches on screen, more than it would actually take when built. Just about all cad tools nowadays work graphically, but the netlist is easier to work with, especially if you want to insert a series component where there wasn't one before. All you have to do is modify the numbering of the points where the new component is placed, not redraw theOn 03/04/2013 08:48 PM, Doug wrote:Oh no, if you read my e-mail a few replies ago my point was NOT "GUI can/should do everything." It was the opposite. I stated I felt this fear of the command line was bad (I like my desktop, I just find there's oodles of power and speed to be had on a command line not had on a desktop.) I was talking about DOS's command line. I *love* POSIX shells, I can do just about anything with them. Not much capability in COMMAND.COM, if you get my meaning.On 03/04/2013 09:07 PM, William Ivanski wrote:Well, it's also used, occasionally, by people who have software the equivalent of which does not exist on a modern system. In addition to programs that were specifically written by a user to solve some problem, there are some commercial programs that have no modern equivalent. One that comes immediately to mind is Eureka, which I think was sold by Borland. Eureka will solve math problems using standard keyboard notation, ala BASIC, which to my mind is much easier to deal with than something like MathCad. If you've ever tried to enter an equation into MathCad, without months of previous experience, you'll know exactly what I mean. I have a DosBox routine installed specifically to run Eureka, which fortunately is now in the public domain. (I once had the non-free floppy disks, but even if I could find them, they are probably unreadable by this time. Or they were 5¼", which amounts to the same thing.) Another program, which I used until I retired in 2002 was EEsof's Touchstone. An extremely expensive RF cad program, it worked with netlist inputs. When HP bought the company, they imposed their graphical interface, which would have worked really nicely if you had a screen about 4 feet by 5 feet to draw your circuit on! I suppose a 30" screen would have worked, but nobody had one in those days. What you could do in two typed pages of netlist would fit nicely on a D- or E-sized drawing, graphically. Sure, you sketched it out on several pieces of paper first by hand, but you didn't put in 4 or 5 parameters for every last component like HP required. There is no modern equivalent that I know of,On 04-03-2013 22:39, Yaro Kasear wrote:When (U)EFI completely replaces BIOS THEN DOS will be completely dead. Right now it's just a horribly obsolete OS used by people afraid of kernels or enterprises that refuse to upgrade some of their infrastructure.It's also used by people who, many years ago, paid for a vital system which runs on DOS, and nowadays can't pay for a better modern systemand the old program is not available at any price. This is progress?(I'm only kidding about that last remark--I wouldn't give up my GUI, but I could wish that some of the old smarts still existed. If you think that the modern graphical approach is so great, try taking pictures outdoors with one of those nice 2" x 3" LCD displays. Give me an eye-levelviewfinder any day!) --dougI'm trying to understand what you're meaning on the Touchstone software... what feature exactly did it have that the billions of other CAD tools don't? I don't know what "netlist" is.Regards.
circuit to make the component physically fit.There are cad tools that really need graphics: they are tools that model the effects of proximity, radiation from the components, etc.
But an awful lot of design can be done without the picture. msub t=60 e=4.2 freq=1.296 mlin 1 2 w=115 l=200 mlin 2 3 w=w1 l=l1 mlin 3 4 w=115 l=200 mlin 1 5 w=w1 l=l1 mlin 5 6 w=115 l=200 res 3 5 r=100(In real life, the line junctions would have bends modeled in; I omitted them for simplicity.)
--doug -- Blessed are the peacemakers...for they shall be shot at from both sides. A.M. Greeley