You are, of course, correct, however, the 816 can run 6502 opcodes, witness the accelerator for the Commodore, and the running of Apple ][ and ][+ software on the Apple //GS. It can also run 65c02 opcodes.

Exegete AKA Roy Miller
Faith Orthodox Presbyterian Church
Apple ][ forever!

I meant emulator.

A board, with a PowerPC, or Pentium, (or, for that matter an Alpha) that plugs into a 6502 family computer, and has a software emulator for the host machine's CPU, giving the host vastly improved speed.

I mentioned the 65816 because it can run do hardware emulation of 6502 and 65c02 chips, as well as it's own native code. Bernie II the Rescue, for instance, emulates an entire Apple //GS on a PowerMac, with emulated speeds upto 20 times faster than the original (depending on the Mac of course) and that emulates in software ALL the //GS hardware.

I'd rather see a board in my Apple //GS, or IIe or Atari 800 that only emulates the CPU, while I use the I/O, sound and graphics of the original machine. Kinda like dropping a large V8 into my `68 VW Beetle

Exegete AKA Roy Miller
Faith Orthodox Presbyterian Church
Apple ][ forever!

It's true that the '816 can do those things, but it's not a 6502/65C02, and the problems that have to be dealt with in designing an application, or even in selecting an applicaton for each are quite different. I'm not sure I would design either one into a commercial application these days, simply because I don't recommend the use of sole-sourced components.

A notable exception, however, is when I design in a sole-sourced parte that has my firmware on board. It is nevertheless risky to do that.

Uli

We used to really shy away from sole-sourcing since it can really leave a small company stranded; but unfortunately sole-sourcing is becoming more a part of electronic design these days, since things are getting so specialized. We use Maxim power supply parts, National Semiconductor digital pots, PIC microcontrollers, connectors, switches, inductors, special Os-Con capacitors, and other various parts that have no second source. I just tell our buyer to stay further ahead on those parts so we can go longer if there's an availability problem. Usually if something is going to be discontinued, the company will issue a lifetime-buy advisory statement for long enough that any customers who order it now and then will get the message in time to do what they need to do.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

The reason I'm always fearful when I recommend a sole-sourced device, is that if it's not being bought in large volume, i.e. 10k per week, or something like that, the chances are that I'll have to buy through a distributor. If the salesman at the next desk to "mine" happens to notice that I'm supposed to get my 250 parts this week, but the order he has for his 40K-parts-per-month customer is being stretched out for a couple of weeks, he may snag the parts intended for me so he can claim he's done his customer a favor.

This has happened to my clients several times, particularly with Motorola, and I have seen several of them go under as a result. Unfortunately, this was while they still owed me money. So, you see, it's not end-of-life issues that are at issue, here, but rather distributor integrity.

That's one reason I've not used PIC's in my designs, nor have I recommended the use of Motorola parts that aren't second sourced, e.g. some of the flash-programmable MCU's.

I don't feel the same way about programmable logic, because it's made in such VAST volume that it's nearly never in short supply and, if it is, there's often a suitable substitute. I also don't have this reservation about the UBICOM (formerly SCENIX) parts because I'd program them and sell them to my clients as appropriate, already programmed. That gives me enough lead time to stock up once the demand arises.

I don't believe I've ever sold a job with any volume with even one sole-sourced part. I have too little faith in the distribution system.

With the exception of programmable logic and microcontrollers, few devices are totally without second source or plannable substitutions. Sometimes it's desirable to provide an alternate site on the PCB for a substituted part. The only devices for which I've had trouble second-sourcing or making some other arrangement have been connectors. For some reason, the connectors I can get from multiple sources seldom include the really slick connector I want to use. <sigh>

Uli

For a product we designed in '94, I really wanted to use one of the 68HC11's, but the auto industry had it all locked up and the part was on allocation, similar to what you're describing. Another part I was eyeing was one of the COP-8's, but National basically said they weren't interested in selling to such a small customer. (They've changed their tune since then.) I don't remember what else I looked into. The amount of ROM we needed and the fact that we wanted som EEPROM eliminated a lot of contenders. I seem to remember looking into TI, but I've always had trouble getting samples and information from them, which makes it pretty hard to do business.

What we did instead was to make our own little board with a 65c02, 65c22, 8Kx8 RAM (which we only use a couple hundred bytes of), 8Kx8 ROM (which is about half full of tight assembly code), a serial EEPROM, a 74HC00, and a few small discretes. It bacame easier to develop the code (which was important for this real-time application), and even when you include the small 6-layer board and the assembly labor, the total per-piece cost was only a buck or two more than the HC11 was going to cost. Since then, Rockwell has decided to quit making 65xx parts, so now we have CMD and WDC.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?