Bryan Posted August 11, 2017 Share Posted August 11, 2017 I was looking inside my PRC and I noticed the only significant IC is a custom labelled 44 pin PLCC from Rockwell. My guess is that's some version of an R6501 or R6511 microcontroller. I wonder if there's any way to dump the code out of one of these. Probably not, since you needed to submit the mask ROM prior to manufacture. Anyway, I discovered something interesting in the Rockwell databook: https://archive.org/stream/bitsavers_rockwelldaDataBook_80778847/1985_Rockwell_Data_Book#page/n529/mode/2up Rockwell made (or at least announced) a dual 6502 microcontroller device with shared resources. 3 Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted August 11, 2017 Share Posted August 11, 2017 I look forward to anything else you discover. My P:R:Connection came in a large Atari lot I got 15 years ago or so. I pretty much forgot I had it until several months back when people began discussing how to get online with a Lantronix box, so now this thing serves as my 8-bit's connection to the rest of the world. Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted October 31, 2018 Share Posted October 31, 2018 maybe some sort of modified cartridge dumper... kind of take a look into it that way... Quote Link to comment Share on other sites More sharing options...
sanny Posted October 31, 2018 Share Posted October 31, 2018 If it's a 6501, maybe that is helpful: http://e4aws.silverdr.com/hacks/6500_1/ 1 Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted October 31, 2018 Share Posted October 31, 2018 Nice follow up! Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted November 1, 2018 Share Posted November 1, 2018 The 6500/1 is actually a 40 pin MCU. So if it's true the chip in the P:R is 44pin then probably it's not the 6500/1. Might be a close cousin though. Quote Link to comment Share on other sites More sharing options...
tschak909 Posted November 1, 2018 Share Posted November 1, 2018 I wonder if there's a test pin? Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted November 1, 2018 Share Posted November 1, 2018 Here are some high-res shots I just took of one my PRC PCB's. Maybe this will help others with some initial identification. With this particular one R1: doesn't seem to work, but R2: does,. It appears to have had some sort of humidity exposure, with visible white film on the bottom of the PCB, and rust on the pins of the 44 pin PRC112486 chip which may be related... Heh... PCB has a bold "Made in U.S.A"... but then on the actual controller chip is "MEXICO" 3 Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted November 1, 2018 Share Posted November 1, 2018 Interesting that the controller chip is a a square package surface mount design as early as that. Well, maybe it’s only interesting to me. It’s not at all odd though that the chip was made in Mexico. Rockwell has had a chip fab there forever, seems like. And it is or was still active until relatively recent years. I have some 6532P 40-pin DIPs that have fab dates as late as 2010. 2 Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted November 1, 2018 Share Posted November 1, 2018 (edited) Here are some high-res shots I just took of one my PRC PCB's. Maybe this will help others with some initial identification. With this particular one R1: doesn't seem to work, but R2: does,. It appears to have had some sort of humidity exposure, with visible white film on the bottom of the PCB, and rust on the pins of the 44 pin PRC112486 chip which may be related... Heh... PCB has a bold "Made in U.S.A"... but then on the actual controller chip is "MEXICO" I don't recognize the Rockwell chip part #. Does someone have a contemporary chip catalog from them? *Using the rockwell catalog linked to earlier I didn't find a match for a 44pin MCU. Edited November 1, 2018 by Dropcheck Quote Link to comment Share on other sites More sharing options...
+mytek Posted November 1, 2018 Share Posted November 1, 2018 It doesn't make sense that they've isolated the Dsub mounting pins from the ground plane. Besides not providing a ground for the shield and shielding case of the connector, It also doesn't provide as much strength for the connector PCB mount if left unsoldered. 2 Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted November 1, 2018 Share Posted November 1, 2018 Maybe? https://www.ebay.com/itm/Rockwell-R65C52J-Dual-Asynchronous-Communications-Interface-Adapter-PLCC44-x-1pc/151017742350?hash=item23295be00e:g:PNYAAOxyoA1RUFhj:rk:4:pf:0 Quote Link to comment Share on other sites More sharing options...
+mytek Posted November 1, 2018 Share Posted November 1, 2018 Maybe? https://www.ebay.com/itm/Rockwell-R65C52J-Dual-Asynchronous-Communications-Interface-Adapter-PLCC44-x-1pc/151017742350?hash=item23295be00e:g:PNYAAOxyoA1RUFhj:rk:4:pf:0 That's only a dual UART similar to two 6551s in a single SMD package. What you would need would be the micrcontroller version. But personally I wouldn't go that route since it's unlikely you will find a good sustainable source for that part. And of course you still need the firmware and a means to program it. Maybe time for an entirely new version based on current tech as has been suggested. A PIC or AVR would have everything needed on board, and could likely get rid of some of that extra glue as well. But of course it would require some pretty serious firmware development. The only other recourse would be to create the microcontroller from discrete components as I suggested in your Mini 850 thread, but you will still need the firmware from the Rockwell chip and some adjustments of such to fit the revised memory mapping. And then we still have the bottleneck that is SIO to contend with. A PBI version with fully buffered UART would yield the best results, but once again we are looking at a considerable development effort to bring something like that into reality. Quote Link to comment Share on other sites More sharing options...
Gunstar Posted November 1, 2018 Share Posted November 1, 2018 Interesting that the controller chip is a a square package surface mount design as early as that. Well, maybe it’s only interesting to me. It’s not at all odd though that the chip was made in Mexico. Rockwell has had a chip fab there forever, seems like. And it is or was still active until relatively recent years. I have some 6532P 40-pin DIPs that have fab dates as late as 2010. That TOTALLY took me by surprise to see a surface mount chip on the PR: connection! I didn't realize they had surface mount IC's in general use that far back either! 1 Quote Link to comment Share on other sites More sharing options...
+mytek Posted November 1, 2018 Share Posted November 1, 2018 That TOTALLY took me by surprise to see a surface mount chip on the PR: connection! I didn't realize they had surface mount IC's in general use that far back either! Yeah it surprised me as well . So if you look at the part number being used on that 44 pin Rockwell (PRC112486), it's pretty obvious that this was a custom chip made specifically for the PR Connection. Hence the PRC part of the part number. Most likely it's based on one of Rockwell's 6500 cores, with custom firmware that makes it into a serial/parallel interface. I did a reverse image search of the chip, but came up with nothing. I sent an email to someone that may have the IP on this particular ICD product, and asked him if he still has anything related to the PR Connection, and if so, whether he would consider releasing it into the public domain. It's a long shot, since I haven't communicated with him in quite sometime, but I figured what the hey, it don't hurt to try . 6 Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted November 1, 2018 Share Posted November 1, 2018 That TOTALLY took me by surprise to see a surface mount chip on the PR: connection! I didn't realize they had surface mount IC's in general use that far back either! We can only expect the hardware/software genius Mike Gustafson was on top of the latest hardware available, and to make it in the most cost effective way! 3 Quote Link to comment Share on other sites More sharing options...
JR> Posted November 1, 2018 Share Posted November 1, 2018 I guess there were different versions of the custom chip too. The one in mine is labeled PRC9985-6. Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted November 1, 2018 Share Posted November 1, 2018 I guess there were different versions of the custom chip too. The one in mine is labeled PRC9985-6. What's the board version? The one in the pic is V 4. Quote Link to comment Share on other sites More sharing options...
JR> Posted November 1, 2018 Share Posted November 1, 2018 What's the board version? The one in the pic is V 4. Also REV 4 2 Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted November 1, 2018 Share Posted November 1, 2018 Interesting. Yours: week 18 1986 Mine: week 19 1987 Since the device wasnt released until 86, maybe all production units are Rev 4, and earlier PCB revs were incremented during development. Have to crack open a few more. Quote Link to comment Share on other sites More sharing options...
JR> Posted November 1, 2018 Share Posted November 1, 2018 3 Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted November 1, 2018 Share Posted November 1, 2018 Mentioning the part # explicitly in the documentation like that would seem to indicate they had some pride in their chip creation. Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted November 1, 2018 Share Posted November 1, 2018 (edited) The each pin needs to be identified as best it can to match the chip up, you can see some of what's what pretty simply... you can be sure the chip is used in many things with the custom part being some programming and assignment- customized print on the chip is also common. Edited November 1, 2018 by _The Doctor__ Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted November 2, 2018 Share Posted November 2, 2018 PRC.jpg That pretty conclusively proves that we are talking about one of Rockwell's 6500/1 chips.in a PLCC 44pin package. Arggg! Now to find the datasheet. Quote Link to comment Share on other sites More sharing options...
+mytek Posted November 2, 2018 Share Posted November 2, 2018 That pretty conclusively proves that we are talking about one of Rockwell's 6500/1 chips.in a PLCC 44pin package. Arggg! Now to find the datasheet. So far not a peep from the guy I contacted that should have all of the IP on this device. If by some miracle we connect up, I'll be sure to ask him for the Rockwell chip datasheet so that the IO assignments can be determined. Because nothing I've found in the wild matches up with it being in a 44 pin SMD package. 1 Quote Link to comment Share on other sites More sharing options...
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