6502.org

I taken some 65C02P4 and R65NC22P4 from utsource (i live in italy), and all chips was good (and fast delivery).
Greetings
Marco

Hello Marco,

Grazie for your answer ; I tried to order from UTsource some weeks ago : very strangely, I've never been able to complete successfully the payment procedure, whatever I tried. I exchanged a few mails with them : they couldn't solve the mystery. I used 3 different browsers, each on 3 different computers from 2 different places... !

Anyway, I found a solution last week, from this post related to AliExpress :

viewtopic.php?f=1&t=4169

I successfully placed an order, now I'm waiting for the parts to arrive (shipped on last Sunday, delivery delay is 20-40 days). I'll tell you more about all that after receipt.

Marc

Hi,

Today I received the last 2 thirds of my order from AliExpress (Rockwell 4-MHz chips) : the R65C22 and R65C51 chips. The R65C02 arrived 10 days ago. I ordered 10 items for each reference, and to say the least I'm disappointed. It's really some kind of lottery, here's why :

R65C02P4 : packaging OK (antistatic tubes), the chips are in good condition excepted that some pins are slightly bent, it seems that they suffered from some rough handling. It's also clear that the pins were re-tinned : the insertion force needed is higher than as usual, and during insertion they seem to "stick" -I don't know if I make it clear, it's what I feeled. Anyway, no bad surprise, they work.

R65C51P4 : first bad surprise with their packaging, they are all piggy-backed, and wrapped into some kind of not-at-all antistatic plastic film ! Second bad surprise : the first one I tried exhibited strange symptoms after 5 minutes : it transmits OK at 9600 baud, but stays mute at 2400... ? I tried 2 other ones, they seem to work. I didn't test them all because.....

...R65C22P4 : same ugly packaging, no antistatic at all ! But the worse is to come : no 4-MHz part. Four of them are 3-MHz, five others are 2-MHz and the last one : 1-MHz. That is really disappointing. Luckily I already had 4-MHz VIAs, those ones I ordered were for spares. Well, I didn't even tested these chips, I'll do that some day when I've got nothing more interesting to do.

I perfectly know that we're speaking about "pulled" parts, not brand new ones from WDC, but not getting what is claimed is absolutely unfair. To me, it's not worth trying to argument with the seller since the price is so low, I'll simply leave the comments he deserves.

Besides all that, there's a funny thing about the ACIAs : 5 of them are marked on both sides :

Top : R65C51P4 / 11470-11 / MEXICO / 0212 A29587-3
Bottom : 11470 / 78647-4 or A31673-4/ MEXICO

??? I don't know what to think about that (rebadged / faked ?)... Maybe someone will tell more ? Thanks in advance ! ...and be cautious with those Chinese suppliers... surely I'm not the first one being unhappy with them.

Regards,
Marc

I'm suspecting that you were shipped counterfeit 65C51s. Someone else around here ran into a similar problem some time ago. I have absolutely no trust of Chinese suppliers. As the old saying goes, the bitterness of poor quality lingers long after the sweetness of the low price. It may cost more to get the genuine WDC parts, but you will not be left with something that isn't what it claims to be.

Hello BDD,

...i've just finished posting a question in the Hardware section viewtopic.php?f=4&t=4231 related to that strange double marking, you were quicker than me

It's what I supposed and feared anyway. You're right, we get what the low price can afford, no more. Even before placing the order I knew that it could happen.
It would be interesting to decap these chips to actually see what's inside ?

I'm sorry this happened to you—it's very frustrating to be all excited about getting your system working, only to end up with faulty parts. While it's entirely possible the 65C51s are simply defective (being pulls, that is always a possibility), my knowledge of what it's like dealing with Chinese vendors makes me feel that isn't the case.

Is there another parts source you can use so you can order the genuine WDC items? I would suggest looking at distributors in the UK, but with their recent decision to leave the EU I'm not sure whether ordering from a UK source would be viable for you.

Yes, it's frustrating but... I do have WDC parts it's simply that I had the futile idea to populate a board "the old way", nothing more. (and I really don't like the broken 'C51s from WDC)

Makes me wonder when/if WDC will get that problem fixed.

From the beginning, the 6551 was not a good design, both in hardware terms and the programming model. Long ago when this stuff was still relatively new, a lot of designers interfaced the Motorola 6850 into 6502 designs, as the 6850's programming model, as well as performance, was better. Of course, that is all old silicon.

Long ago, I got busy on finding a better UART that could be adapted to the 6502 bus and would support much higher data rates. I settled on the Philips/NXP SCC26xx series and have used them for more than 25 years. Oddly enough, although the 26xx series is designed around the Intel x86 style bus, they are readily attached to a 6502 with simple logic. My POC v1 unit currently uses an NXP 28L92, which is a dual channel part. In the past, I've run a 26C92 and 2692A, also dual channel devices. POC V2, which is under construction, will be using the NXP 28C94, which supports four independent TIA-232 ports.

For single channel use, NXP makes the 28L91, which is essentially one half of a 28L92, and would make an excellent alternative to the 65C51. Aside from the UART itself, there are programmable I/O pins and a high resolution counter/timer for use in various ways. In POC V1, I use the counter/timer to generate the jiffy IRQ that maintains the system clock, an uptime counter and a software timer used for generating accurate time delays. Unlike the timers in the 65C22, the UART timer runs at a constant speed that is ultimately determined by the 3.6864 MHz clock driving the device. This means the Ø2 clock rate can be arbitrarily changed with no effect on timekeeping accuracy.

All of the NXP UARTs support a wide range of data rates, up to 921 Kbps. Interfacing to the 65xx bus is not complicated.

Thank you very much for your suggestions, BDD !

I've been reading for a long time your NXP-related posts, these components are valuable. My current purpose was about speeding up a board using exclusively "old silicon". That said, of course I'd switch to tne NXP family if I were on the way to a new project.

About WDC not fixing their ACIA bug : I suppose that it's a mere mask geometry defect, such as a missing or parasitic connection. Mr Mensch already has the cure, undoubtedly ! I suppose that the main reason for not doing it lies in a huge batch of yet-to-sell chips added to the high cost of a mask set, other reasons are probably linked to what you mention : not so good design, a marginal market for DIP packaged 'C51s... The latter one is what makes me question the financial (non)sense of producing counterfeits for this precise circuit...

You're welcome.
I started a topic a while back on the NXP UARTs in the hardware forum. When i have some spare time I will post information on how to interface one to the 65C02 and 65C816. Basic logic gates are all that is required.
The reality is probably there is little demand for the 65C51, other than to hobbyists. WDC's 'C51 is a relative new product when compared to the 65C02, 65C816 and 65C22. I'm puzzled as to why they made the investment to design and produce it.
Dunno. There may be enough demand from hobbyists to warrant a fake knockoff.

I wonder how many of these things are not knockoffs at all, but that everyone in the Orient has a brother-in-law or other connection to slip them some genuine product under the table to sell.  WDC is a fabless house.  What secret things are going on at the fab houses they use?

One does have to wonder about that. My understanding is industrial espionage is rampant in the Orient. If a fab is making your devices how do you know that they aren't supplying others with your technology and trace secrets, or even dice so others can cobble together knock-offs?

For a counterpoint, see Bunny Huang's guide to Shenzhen, or the documentary
https://www.youtube.com/watch?v=SGJ5cZnoodY

There's a healthy sharing economy going on, which has more to do with innovation and getting products out than to do with the idea of knocking things off. There's certainly a culture where personal relationships matter more than how much money you have - if you just throw money at a problem and apply no due diligence, you deserve what you get.

The bottom line is, and this should be blindingly obvious, not all suppliers are the same - whether they are American or Chinese or European, you need to take reputation into account. Alibaba is a market, and the various suppliers there should not all be taken to be equal.

I do find prejudice rather distasteful - let's not slip from anecdote to generalisation to prejudice.

I subscribe to your various points of view in that it's easier to put more trust in well-known and established suppliers.

By the way : these R65C51P4 chips draw less current than the older R65C51P2 ones (20 years before), I still need to accurately measure that. I only noticed that the 7805 regulator runs cooler. It could be that Rockwell improved their process, which naturally gives less power-hungry chips. -provided they're actually genuine...

For what it's worth, the 65Cxx chips (most of them R65CxxPx, a dozen or so) I have bought on Ebay over the years, from e.g. utsource and adeleparts, have been exactly as described, and all in good shape.

-Tor