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CBM 4040 5 Flash Failure! Need parts.

D

DistantStar001

Experienced Member
Joined
May 8, 2019
Messages
178
Just as the title says, it was working perfectly, and then it wasn't. Drive 1 spins, Drive 0 does nothing. It doesn't matter which drive is Drive 1. I looked up the error code and learned that it is either the 5630 or 6504. Unfortunately, I have no idea where to get the 6530. I checked eBay and the only ones listed are either part of a Kim 1 or an original ceramic package for $500 (and that's the cheaper option). Obviously, neither is an option. There are a few 6504s listed, but I'm not sure I trust the sources. Also, ArcadeComponents doesn't list the 6530 and the 6504 is out of stock. PolyPlay lists a MOS 901869 / 6530-048, but doesn't list the 4040 as a compatible machine. Is this part compatable? And if not, does anyone know where to get these?

Almost forgot to ask: Laying odds, which one is most likely the culprit?
 
I think someone makes a 6530 replacement consisting of a PIA and a separate ROM if you do a search.

The 6504 is a processor I think... There is no option for this if it is dead...

Dave
 
daver2 said:
I think someone makes a 6530 replacement consisting of a PIA and a separate ROM if you do a search.
Click to expand...
I found it. But the PolyPlay chip is cheaper. And if it's the same part... Less risk of compatibility issues.
daver2 said:
The 6504 is a processor I think... There is no option for this if it is dead...
Click to expand...
An MPU, yes... And no. There isn't an alternative part. They're pretty cheap on eBay, but the fact that I'm having trouble finding them anywhere else is making me nervous.
 
We built a NOP generator for the 6504 once. That will check it out to make sure it isn't dead!

Dave
 
I think you can get what you need from Monotech in NZ:

monotech.fwscart.com

6530 RRIOT Replacement kit for CBM IEEE Drives

If you have diagnosed your CBM IEEE drive and discovered the 6530 is faulty, you can use this to replace it. I also carry other parts used in these drives including 2114 SRAM, and 6502 and 6504 CPUs. This does not come assembled . You must solder it together. The photos only show the completed...
monotech.fwscart.com monotech.fwscart.com

It was based on Ruud's design, they say.

Monotech are a good vendor.

I cannot say much about another source you mentioned. Except to quote a scene from Lost in Space: With the Robot waving his arms and announcing: "Warning, Warning, Will Robinson".

When the robot was asked what was wrong he explained that he received the so called good value part, but when plugged in it cooked up because it was a re-labelled part not even resembling the original IC. But the Robot knew it could just have been bad luck, so he gave the seller the benefit of the doubt and bought another one to try, but history repeated itself. The Robot refused a third attempt because he took the advice of Mr. Einstein: Madness is repeating the same experiment over and over and expecting a different result.
 
Ruud said:
I have spare 6504s if needed.
Click to expand...
I think I might take you up on that. How do we proceed?
Hugo Holden said:
I think you can get what you need from Monotech in NZ:

monotech.fwscart.com

6530 RRIOT Replacement kit for CBM IEEE Drives

If you have diagnosed your CBM IEEE drive and discovered the 6530 is faulty, you can use this to replace it. I also carry other parts used in these drives including 2114 SRAM, and 6502 and 6504 CPUs. This does not come assembled . You must solder it together. The photos only show the completed...
monotech.fwscart.com monotech.fwscart.com

It was based on Ruud's design, they say.

Monotech are a good vendor.
Click to expand...
Unfortunately, they're in New Zeland. Shipping from there to the US is really expensive, making them an admittedly good, but last resort for me. The drive's worth it. But I'd like to explore more affordable options first.
Hugo Holden said:
I cannot say much about another source you mentioned. Except to quote a scene from Lost in Space: With the Robot waving his arms and announcing: "Warning, Warning, Will Robinson".

When the robot was asked what was wrong he explained that he received the so called good value part, but when plugged in it cooked up because it was a re-labelled part not even resembling the original IC. But the Robot knew it could just have been bad luck, so he gave the seller the benefit of the doubt and bought another one to try, but history repeated itself. The Robot refused a third attempt because he took the advice of Mr. Einstein: Madness is repeating the same experiment over and over and expecting a different result.
Click to expand...
The 6504 sources were found on eBay, and located in China. Which is why I'm hesident at best. A cheap chip from China that no one else has...

As for PolyPlay, I've ordered from them before. Mostly C64 stuff, but they've always been reliable (if a bit slow on delivery). They're located in Germany, support any number of retro machines, and their prioces aren't bad.

dave_m said:
The 6530 RRIOT chip part number for the 4040 drive is:
901466-04 (6530-34) - Shugart SA390 drives in 4040, DOS 2.2

Workarounds include using an old 6532 RIOT chip (still found) with an EPROM to duplicate the 1K ROM in the RRIOT.

For design info, see these old designs that are no longer for sale:

http://blog.tynemouthsoftware.co.uk/search/label/6530

http://www.baltissen.org/newhtm/6530repl.htm
Click to expand...
Yeah.... Admittedly I've already jumpeed the gun on this, as I've already ordered the afore mentioned chip from PolyPlay, and it's too late to cancel now.

I found the troubleshooting guide and from what I can tell, it likely won't work (Unless I replace the drive mechanisms). I thought that it was only responsible for the zero page, but it seems to have additinal code that makes them drive-mechanism specific. In any case it won't hurt the chip to try, and it's not going to be here for a few weeks at best. I guess, worst case, I have a rare chip I can traid. And who knows, maybe I'll get lucky and it's the 6504 that failed.
 
When you get your replacement chip, from wherever you get it, after you insert it, put your finger on it, then power up the drive. If it is a relabeled IC, with different internal architecture, likely it will heat up fairly violently, so it is worth double checking as left long enough other IC's connected to it could possibly be harmed. If you chip from Poly play works, can you report that result on this thread ? I have been looking for a source for these working IC's too.

The Monotech option is the way to go, despite the extra shipping cost as it is proven to work by them and it would save you a lot of grief. Also, if that did not fix your problem, you could then be 100% confident your fault was elsewhere and move on with the repair, otherwise you might end up in no-Man's Land.

It is good advice, have a look at post #19 #20 on this thread:


Generally, if I receive fake IC's from an ebay seller I don't name and blame the seller because, in many cases, they have no idea about it, have no way to test the chips and they get deceived by their supplier or the supplier who supplied their supplier etc,etc,etc until you get back to the house that Jack built. So, all I can really do is give you a hint and you would have to read between the lines and pick up on the clues. It is "fakes in a supply chain" problem.
 
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Hugo Holden said:
When you get your replacement chip, from wherever you get it, after you insert it, put your finger on it, then power up the drive. If it is a relabeled IC, with different internal architecture, likely it will heat up fairly violently, so it is worth double checking as left long enough other IC's connected to it could possibly be harmed. If you chip from Poly play works, can you report that result on this thread ? I have been looking for a source for these working IC's too.
Click to expand...
Sure thing. But if it works that means that the chips from the 8050 and 8052 drives are interchangeable with the 4040.
Hugo Holden said:
The Monotech option is the way to go, despite the extra shipping cost as it is proven to work by them and it would save you a lot of grief. Also, if that did not fix your problem, you could then be 100% confident your fault was elsewhere and move on with the repair, otherwise you might end up in no-Man's Land
Click to expand...
If replacing the 6504 doesn't work, that will be my only option. Interestingly, the bulk of the cost of the Monotech part is the 6532... Which I can't seem to find either. At least outside of Monotech ($15 extra, but if you ca't find it anywhere else, I guess that's a deal!).
 
So... I've now replaced both the 6504 and the 6530 (with the Monotec replacement) and I'm still getting the 5 flashes. I'm going to replace the sockets and see if that is the issue. As it is, the Monotech part did make a bit of an improvement as drive 1 spins for a moment then stops. The original either has no drive activity at all or the drive spins continuously. But if the sockets aren't the problem, any ideas on what else it could be?
 
Well, I seem to remember (ages ago) that we made a NOP generator for one of these beasties and worked through the schematic in a logical way (in a similar manner to a PET repair).

Dave
 
OK. Going on advice I got from the Commodore PET group on FaceBook I was advised to replace the 2114 RAM. I've done so, along with the socket for the 6530. Now, instead of a 5 flash error, I'm getting 1 flash. So progress I think. However, this means I probably have an issue with one or both 6532 RIOT chips (according to the manual). Any idea where I can get those?
 
Hen's teeth I am afraid (unless you get a donor machine - and they may be faulty also)...

There is a small PCB available that can take an EPROM and a conventional PIA to 'make' a RIOT.

Dave
 
daver2 said:
There is a small PCB available that can take an EPROM and a conventional PIA to 'make' a RIOT.
Click to expand...
The 6532 doesn't contain ROM, that's the 6530. The 6532 is an IC that cannot be replaced with another IC, except a FPGA or CPLD. And 6532s can still be found.
 
Hugo Holden said:
@DistantStar001: What happened when you got the chip from Polyplay, did it work ?
Click to expand...
Sadly no. Like i said, it was meant for a 8050 or 8052. So installing it gave a solid light error. I suppose I won't know if it's good or not until I can install into one of those drives.

To be fair to PolyPlay, this info was disclosed in the description, and everything else I've gotten from them (mostly C64 chips) have been both functional and authentic. Honestly, their a very reliable company.

On a side note, I replaced the sockets for the 6532s and still get a single flash error. So I guess I'll have to find some replacements after all.
 
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