Magnus, See my post of a few minutes ago.
The GRI and Delay counters need to be 5 decimal digits. My current thinking is manual entry of the numbers via BCD coded thumbwheel switches. LORAN-A has 24 possible GRIs; in three blocks of 33 PPS; 25 PPS; and 20 PPS. It also has 4 RF frequencies. Currently I plan only one Slave, but a second would be an easy addition. -John ============== > On 08/01/11 03:28, J. Forster wrote: >> I'm looking at building a LORAN-A simulator to run a vintage display. > > Hmm. Generating blips programmed in repetition rate and delay as steps > of a 10 MHz clock should be sufficient and fairly straight forward. A > lower clock such as 1 MHz would probably work well (and simplify the > design). A programmable delay (needs to be 19 bit for 10 MHz and 15 bit > for 1 MHz) using standard synchronous counters should not be too hard. > Once designed it's a matter of deciding how many slaves shall be > supported. A PIC or AVR could do the NMEA position to delay conversions > needed, and I mostly worry about the math-support on them, which only > shows that I haven't done any real project on any of them. > >> I used to design stuff with gates and counters by hand, and can still do >> so, but it's tedious. >> >> Does anyboby know of any freeware that can be used to draw up logic and >> simulate its operation, including propagation delays? I don't need >> exotic >> chips or any analog functions. A library of common 74... and 40.. would >> be nice. >> >> Freeware strongly preferred. > > Eagle, GEDA/GNUCAP, Electric and KICAD would be my main suspects. > > Cheers, > Magnus > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
