Intel 8748/8749 PIC, compatible PICs available anywhere?

Spendy.

Reason I'm asking is that it would actually _work_ with a primitive use of the parallel port on PCs, as a way of expanding it's ability to control I/O lines and for sinking capability (5mA on all 16 pins at the same time.) Of course, parallel ports are going away, too. Oh, well. I suppose, sine the max delay was about 700ns or so, that a micro using an internal RC osc could kind of double for it in many circumstances and possibly for less than $3.71 (24 pins do cost money, though.)

Thanks, Jon

Nope, it's what the new law forces them to do. A classic case of where un-leashed lawyers can cost a company sales and good will, whilst they are doing what they are supposed to do, which is protect the companies trademarks. If something passes into general use, then it is not trademarked.

With something like PIC, it hardly seems worth the bother!!.

-jg

I'm aware of the idea that if a company doesn't work to aggressively protect trademarks, that they lose the right to enforce them on others.

Perhaps. But you'd think that intelligent people are in charge and can tell the attorneys what to pursue and what not to pursue.

Yes, that much I understand.

It does.

I'm still not sure if Intel's use was considered infringing. There is no question in my mind that Intel used the term, PIC. You didn't address this, either. Is it? Or not? If not, doesn't that block Microchip's right to enforce it? I'm confused about this.

Jon

Nah, not really. Interesting to learn about the history of PIC. My apologies that I asked for an Intel 8748/49 PIC and not a simple µC.

Thanks, I got that. I´d be a newbie in developing any microcontroller code at all. It´s really the case that I am stuck with a garage door opener which just failed and which was installed into my garage back in 1990.

I see. Well, I´m not yet decided how much effort and/or money I am going to invest into the garage door opener just to get it going again. On the other hand, the garage door opener´s hardware itself is really rock-solid. Thus, I will definitely not be decided before I will have exchanged the PCB´s capacitors first, just to see whether they are the culprit ones on my defective PCB.

Thanks, got that now.

I know. *sigh* Even I studied computer science back in 1995, I was never in charge of having to do any code development for microcontrollers at all. So this is my first time to having to make up my mind about µCs, especially about 8748/8749 ones. :)

Thanks for your kind offer. I´ll get back to it when I´ll be decided to take the adventure to start developing own µC code for an alternate microcontroller for my garage door opener.

Right. Or to simply skip the use of any microcontroller at all and to realize an alternate control PCB which is mostly based on contactors/relais like they are still widely used in elevator control systems. *g* Ok, but I didn´t intend to get any offtopic here.

Kind regards, Joachim

Right. And thanks a lot. I really highly appreciate your quick reply. I´m sorry I didn´t find any more time before the weekend to continue reading all replies. My apologies.

Of course; - a much more sensible approach would be to see that any users acknowledge that it is a tm of Microchip, and even say 'used with permission of..' - but now Microchip are now a 'billion dollar company', so they get the billion dollar mindset, especially in the legal dept, and one gets the impression the lawyers are running the place.

Not a good look, for a tech company, and bad for long term business.

What intel did 25 yrs ago does not bother today's lawyers. So long as they bang off a few cheap letters, then can say they are currently protecting the trademark

The only thing that would block 'Microchip's right to enforce it', would be for someone to take the considerable expense to argue that in court, and win.

-jg

Well, the IC is a 16-pin component. I currently don´t have any more than a meter with a built-in logic tester. While the PCB is resting silently in front of me and is connected to +12V (and to +5V via a voltage regulator on the PCB) the 16-pin IC shows up with the following readings:

Pin 1: Low , 0.000 kHz, 0.231 V Pin 2: Low , 0.000 kHz, 0.167 V Pin 3: Low , 0.000 kHz, 0.230 V Pin 4: ----, 0.050 kHz, 3.468 V Pin 5: High, 0.000 kHz, 4.979 V Pin 6: High, 0.000 kHz, 4.979 V Pin 7: Low , 0.000 kHz, 0.202 V Pin 8: Vss (GND) Pin 9: Low , 0.000 kHz, 0.204 V Pin 10: High, 0.111 kHz, 4.971 V (frequency slightly alternating around this frequency of 0.111 kHz) Pin 11: Low , 0.000 kHz, 0.012 V Pin 12: Low , 0.000 kHz, 0.012 V Pin 13: ----, 0.000 kHz, 3.335 V Pin 14: High, ?.??? kHz, 4.987 V (frequency randomly alternating from

0.000 kHz to more than 2 MHz) Pin 15: Low , 0.000 kHz, 0.000 V Pin 16: High, 0.000 kHz, 4.984 V

PCB front side:

PCB back side:

I hope not to become any offtopic. If so, please apologize and simply ignore.

Thanks and kind regards, Joachim

I should have reviewed that past posts. I had a simular problem with a burned out transistor in a garage door opener. ( controlled that light with a relay) I could not find a transitor that would work in the circuit. I guessed that the rest of the circuit was also burned out.

So I ended up buying another unit.

( Wife got tired of me fooling with it, no sense of adventure ;-)

donald

Perhaps the Philips PCA8574 ?

Good question. Could it even be the case to be a PAL, i.e. a Programmable Array Logic?

No, I know of no 16 pin SPLDs, but the 82S123 (bipolar PROM) comes in

16 pins, and we have use those as PALs many years ago.

One clue is how warm it gets :)

-jg

Circa 1980, Intel introduced HMOS including an upgraded HMOS 8x49/39 and

*some* variants of 8x48. Intel referred to their microcontroller families as MCS, not PIC. I consider MCS-48 an abomination compared to MCS-51 which succeeded it.

I have some used 8748s, plus one of those cool ceramic bond-out versions with machined sockets to piggy-back a standard (2716?) EPROM. (That is to say, "standard" as of 30 years ago!) I think the piggy-back version cost several hundred U$D back in the 1970s. I also have a "1981 MCS-48 User's Manual" and other related "ancient" items.

I am located in the USA. If you are unable find any locally, Joachim, I would be willing to part with any/all of these treasured antiquities.

Regards, Steve Hoyt

--
Hoyt Engineering
http://www.HoytEngineering.com

Thanks a mil, Steve. I will see what I can still get here in Germany. And I may come back to your kind offer.

Thanks, Joachim

Well, a German guy just gave me the hint that the 80(C)48/80(C)49 are pin and opcode compatible. I just started to check for pin compatibility and it really seems to me that they are pin compatible. Can anyone here please give his or her experience when it comes to opcode compatibility? I know that the 80(C)48/80(C)49 are equipped with a PROM only and not with an EPROM. But that´ll not be a problem for me. :)

TIA, Joachim

I forgot to mention: The 80(C)48/80(C)49 are from OKI Semiconductor.

The 8748 and 80C48 bith use the MCS-48 instruction set.

I thought you were trying to fix a garage door opener ?

- The 80C48/80C49 are mask ROM versions, so have MOQs of some thousands. The 80C35/39 were the external memory model, tho the 80C48 can be used in romless mode with external memory (latch+flash), which costs many package pins.

- but you'll need to get the code somehow first, and the original chip may be damaged...

-jg

The -only- difference between the 8x48 and the 8x49 is the amount of memory.

The -only- difference between the 878x and the 804x is the type of memory.

The 804x does have an 'EA' pin, which will cause it to use external memory.

Email me. I have a small stack of 8748's somewhere.

G=2E

Thanks for your kind offer. Currently, the small company who manufactured the garage door opener are still searching in their archive for already programmed 8748/49 for me. My garage door opener was installed 17 years ago. So, this may still need some time. I can´t hurry things up, but I will keep you all posted.

Kind regards, Joachim