| ??? 10/18/06 22:32 Read: times |
#126710 - Been there, done that ... Responding to: ???'s previous message |
Erik Malund said:
Richard Erlacher said:
to what are you saying "nope," here? That you HAVE to use a drop-in replacement. You can just as easily use another devboard. Unless, of course, you "get cought with your pants down" and find that you have misjudged the processing power needed. Erik Malund said:
Richard Erlacher said:
I've looked at SiLabs' boards and, if any of them were competitively priced and had a sufficient prototype area on them, I'd have some of them in house. I don't. Of course, nobody can compete with someone selling something designed when the king of diamonds was a jack, the investment in design etc. has been recovered many times over. and if enough people are sensible enough not to buy antiques, the boards will be "priced to unload" HOWEVER I am really curious what you are making that a $99 devboard will make it too expensive (I recall something about your rates). Also, if you "looked at SiLabs' boards" a bit more closely you would find that they have plug-ins. Anyhow, as usual (re the WSI chips) you do not catch that an example is an example. You are, by no means, forced to use SILabs to abandon the past, there are many other protoboards with current technology e.g Phytec. Erik Malund said:
Richard Erlacher said:
It's clear that you don't do standard parallel interfaces much, else you wouldn't spout such drivel. If a "standard parallel interface" means 8255 I happily agree; however in the last, say, 6 months, I have done, at least, six. It is clear that you do not use current technology, else you wouldn't spout such drivel about your favorite antique. erik I think you've misconstrued what's been said. I've pointed out many times that I don't like MOS LSI for I/O because they don't have enough output current, hence, you can't do much with 'em, e.g. drive a BJT to do useful work, or, in some cases, even drive a MOSFET, since the Vgs must be higher that it can tolerate. When I've used 8255's myself, I've done so because they were already on the board I was using. My first one was on an 8080-based Multibus board made by Intel. Even Intel recognized that they wouldn't do useful work, so they provided TTL buffers to drive the I/O cables. The 8255 is flexible enough that it's been used to implement SASI, SCSI, IDE/ATA, Pertec, and other similar interfaces. "Standard" doesn't mean 8255, but 8255 will do it if called upon. I use boards that allow me to put together simple functions, and also support construction of more complex ones. I don't like what Phytec and several other manufacturers have done, limiting their "expansion" to their own products, mostly by using small, fragile, connectors unsuited to many tasks, and making their proto boards as small as they have. My favorite CPLD board is about 9" x 10" and consists mostly of prototype area. My favorite FPGA board is one that's no longer made, but has about 1/3 of its area in proto space and has plenty of I/O. My favorite 805x board is the NMIY-0031 costing $39, not because it's cheap, but because it hasn't got features that get in the way, though it does have features. It also has a DIN41612 connector site at the far side of its prototype area in case one needs to expand. I can run the DS89C450 on it from internal memory (with one "adjustment" to the board) and at whatever rate I like. Of course, it won't run its local memory at full CPU speed, but who cares when I can stretch the bus cycle to accomodate it. I've combined over a dozen, sometimes two dozen, of these or similar boards, sometimes with various MCU's, in one or another system for purposes of proving concept, which is what I do, mostly. When I'm done, the boards and cables go back on the shelf. RE |
