Brads Electronic Projects Forum

Do you find wire wrapping to be an easy method for building your circuits? The same prototyping methods that are good for digital are not good for analog, and vice versa. For digital , yes, wire wrap is very practical, easy, reliable, and makes for much better density and performance than soldering...

Aries used to sell WW PLCC sockets which I bought years ago http://gw7.no-ip.com/65xx/WW_PLCC_44.jpg and when I lamented on 6502.org today that AFAIK no one makes them anymore, BigEd gave us a link to http://uk.rs-online.com/web/c/?searchTerm=wire+wrapping+std+PLCC+socket&sra=oss&r=t which stocks th...

I've used Jan Crystals too. They used to have (and hopefully still do-- their website is being re-done ATM) an inexpensive service for custom frequencies which I helped myself to when I was active in amateur radio. For processors though, the off-the-shelf frequencies probably are plenty good. To see...

I use an itty-bitty pencil iron with a sharp tip for things like chip resistors and capacitors and SOT-23 transistors and diodes, but a 3mm-wide chisel tip for the ICs. You want it to cover several leads at once. After tacking a couple of corners down with good alignment, you go down the side and pu...

If using a microcontroller, why not just have its clock frequency crystal-controlled, and set up a time to interrupt at every rollover and do the RTC in software instead of using a separate RTC IC.

I also didn't know that there was such a community for the CPU, it is obviously still going very strong.

Actually the 6502 community and expertise are increasing at 6502.org, and there are good things happening there that I would not have expected just a few years ago.

I²C is slower because of the passive pull-ups (just resistors) on the clock and data lines, and the resistors have to charge the bus capacitance. In many cases you can have the clock line fed with a totem-pole output from the master, but that definitely wouldn't work with the data line. Then there's...

Right. A flash converter requires a lot more analog comparators. An 8-bit half-flash converter does the first four bits all at once and then the next four all at once. I'm not sure I've seen any 8-bit (full)flash ones, although I'm sure they exist. I know I've seen 6-bit ones. There are so many thou...

I just remembered that although the bias voltages I was talking about were for bipolars, I also had a situation 25 years ago where I used the pinch-off voltage of a JFET to regulate the low voltage at miniscule current to keep a SRAM alive when the rest of the circuit was powered down, and that when...

http://wilsonminesco.com/6502primer/potpourri.html#ADC IIRC, it's fast enough to just read it like a memory location if you had a bus of only 1MHz. I'm running at 5MHz, so I have the A/D on a 65c22's port. I have a couple of web pages a bout the workbench computer at http://wilsonminesco.com/BenchCP...

I think the only safe thing, if you really want to do it that way, is to use a comparator or op amp. The input voltage will cross the threshold set at the other input, then the output which is either high or low (not in between) goes to the microcontroller input pin. A digital input's threshold volt...

Are you measuring right at the inverter IC, or somplace farther away on the board? (I'm wondering if you're seeing the effects of board problems, not inverter problems.)

I really have hit a wall with assembly so I would like to see if I can make bigger and better things with a language that can help me achieve that. Without speed and memory penalties, you can advance a lot by using macros, including to make program structures like you would find in higher-level lan...

I've done a fair amount of digital recording with my workbench computer, and now am working on something to record on flash with a PIC16F72. Here are the last couple of paragraphs from the A note about A/D and D/A jitter (and other performance considerations) section of the circuit potpourri page of...

discussed on another forum, with names and URLs, at http://forum.6502.org/viewtopic.php?f=1&t=1913