Using 4000 series logic to drive....?

piglet... my buddy. :^)

George (a bear with very little brain) H.

Many years ago I had problems with that "white proto-board" at

You mean you've never used the crescent hammer? (whatever tool is handy, is my motto.)

I've got what I call a monkey wrench that has a nice flat hammer head on the back. (two square jaws, the lower threaded, a bit like a pipe wrench, but not as wiggley.)

George H. George H.

Sure, I've had my share of problems with flaky connections and such... I'll also make flaky solder joints that will drive me nuts.. till I find it. (I'm not giving up solder. :^)

George H.

The problem I encountered was cross-talk... to damn much capacitance pin-to-pin... even at 40kHz :-( ...Jim Thompson

I haven't used one in 45 years. ...since the bad connections kept burning up 709s and my college adviser getting pissed that I was burning up $2 parts every few minutes. Well, he was pissed before he burned his finger too. ;-)

Be careful with screws. Anything structural needs structural screws. Nails are soft steel and will bend rather than break. Most screws are hardened and will fail if used as structural fasteners. In particular, sheetrock screws are useless for anything other than sheetrock.

Why not glue the carpet? It'll hold better, particularly when the rack gets wet.

Everything new from X and A is very expensive. They're really only interested in the very high end and if you need it, you'll pay. However, the volumes for the applications are typically miniscule.

OTOH, there are MCU makers that are embedding DRAM (also not monolithic) in application specific MCUs. These aren't excessively expensive. The markets won't allow it but make up for it with volume.

Lattice makes some really nice parts. The onboard flash can be programmed over I2C (and can be accessed from the FPGA fabric). Makes for some interesting reprogramming or in-situ update possibilities.

There's the trick of running a ground line/section between two traces.. but I'll admit tricks at 40 kHz is pathetic... white proto, it is what it is.

George H.

It's about 2 pF row-to-row, which is enough to cause problems in lots of situations. (Audio not so much.) Ground inductance is pretty evil too.

Cheers

Phil Hobbs

It's surprising how often that something within reach will work.

FWIW my present prototype mix includes: push in plastic board, wirewrap vectorboard, soldered veloboard (stripboard), soldered vectorboard, soldered DIP board, soldered dead bug, soldered Manhattan, and soldered one-off PCB. SMT winnows the mix down to soldered Manhattan and one-off PCB.

SMT dead bug's probably too surreal/cubist for me. SMT DIP carriers may enable older tools to stay in the mix.

Thank you,

We use modest volumes of both, with piece prices from about $10 to $180. Both X and A seem to be dismissing the small-volume market lately.

Buy a few tens of their top-end FPGAs and they'll probably talk to you again.

??? You have it wrong. They dismiss the low profit market. They make chips that they sell very few of *ever*, but at thousands of dollars each they don't need to sell many.

They are happy to sell high volumes and will even test chips to your specific design to approach ASIC price levels.

They just don't deal much with small volume buyers of low priced chips. Never did, never will.

Last year we bought about a tray of $10k FPGAs. The support we received was equally crap before and after.

Allan

Odd, I've wired up a Z8 as a BASIC computer on the white pincushions, it was fine. Logic margin and low gain helps, I suppose.

Most boards are helped by bolting 'em to a metal plate (and grounding it, if you can), and by using long-lead transistors (so you can plug the gate/base into a quiet neighborhood).

I guess it's because it's more expensive to manufacture anything mechanical.