Dolby CP950 freezing

[Stefan Scholz]

I really like C since it is "close to the machine." I first hand coded MC6800 code (still remember 0x7e is JMP, 0xbd is GOSUB, 0x3f is SWI, etc.). Then 6800 assembly, FORTRAN, COBOL, PDP-8 assembly, PDP-11 assembly, and C. But, as with any language, the machine does what you tell it to do, not what you want it to do.

So true, I started i8080/ i8085 assembler to build control systems at an engineering office, later in Fortran and C, close to machine level. IIn university, they wanted to teach us some weird "programming languages", far from machine level. And I had to work on Motorola 6800 coding (did anybody actually use Motorola microprocessors?).
I passed the exam, just with the assembler coding. I skipped the weird programming language task. As both were 50%, I was fine, and just passed it.
What hate so much about today, none is interested in doing things efficiently. RAM and ROM is ample, and no need to look out for overflow. In theory. Works nice on the bench, where you frequent reboot, turn of power to solder something in/ change.
On for weeks? Trouble, for sure. And yes, audio processors are no longer just source switches with a little EQ on board. Eventually CP 750 has been something like that. CP 950 is a computer with mainly digital audio interfaces, complex decoding, DSP and support for (limited) analog, AES, networked audio.

[Harold Hallikainen]

(did anybody actually use Motorola microprocessors?).

Yes! I designed a couple products around the MC6800 and MC6802. One of them is here. It included a BASIC interpreter we licensed from Microsoft in 1980.

Some amazing stuff is happening with more recent computer languages. Since I started in hardware (vacuum tube circuits in high school), I tend to keep hardware in mind when doing software.

All fun stuff!

[Marcel Birgelen]

I really like C since it is "close to the machine." I first hand coded MC6800 code (still remember 0x7e is JMP, 0xbd is GOSUB, 0x3f is SWI, etc.). Then 6800 assembly, FORTRAN, COBOL, PDP-8 assembly, PDP-11 assembly, and C. But, as with any language, the machine does what you tell it to do, not what you want it to do.

Haha, I guess we'll never get rid of C, although Rust is making inroads... I still don't know what to think about Rust... But well, I actually don't hate C. What I do HATE though, with a flaming passion is C++.

I've done my first programming on the more "managed" programming languages, like BASIC, PASCAL, FORTRAN... My first C experience felt like playing with matches and gasoline... Once I got to know x86 and 6800 assembly, C, as a kind of macro assembler on steroids made a lot more sense to me and that's what I still consider it today: A macro assembler on steroids with some standard libraries thrown into the fire.

I've never done PDP-11 assembly, but I had to keep one alive for many years. It's interesting to see how a platform developed in the 1970s lasted so many years, just like the AS400... The same for COBOL I guess. I wouldn't call myself a COBOL programmer, but I've had the distinctive "pleasure" to fix up some decades old COBOL software throughout the years. As a matter of fact, about a year ago, I did some COBOL to Python translation work, using a lot of help from some of our AI friends... It remains to be seen if that Python code will ever reach the age of the COBOL code it replaced...

[Frank Cox]

"C - the footgun of programming languages"

I've been playing around with Cobol off-and-on for a while lately, as well. I have no actual use for it but it sure has some interesting concepts.

The oldest program I've written that's still running is a water vending machine. It doesn't do much -- counts pulses from the token collector, counts pulses from the water meter and operates a relay to open and close the valve. And tells you how many tokens are supposed to be in the bucket.

The hardware has replaced several times but the actual program has never been changed in any way, since about 1981.

[Harold Hallikainen]

I took FORTRAN and COBOL in classes with punched cards. In the COBOL class, we'd punch our cards, walk over to the HP computer, drop the card deck in and push start to get a printout of our error messages. In that class, we had to write a simple accounting program. The instructor explained that "all you need to know about accounting is that credit goes on the right because it has an R in it." Of course, the common abbreviation for debit is DR, but he did not mention that. Another time, I took my program to him looking for help. He looked at it for a while and then said, "I'm sure glad it's your problem!".

Fun times!

[Caleb Williams]

Just for the curious, here's some hardware info from the CP950:

/etc$ lscpu
Architecture: aarch64
Byte Order: Little Endian
CPU(s): 4
On-line CPU(s) list: 0-3
Thread(s) per core: 1
Core(s) per socket: 4
Socket(s): 1
Model: 4
BogoMIPS: 100.00
Flags: fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid

/etc$ free -h
total used free shared buff/cache available
Mem: 1.9G 659M 827M 37M 495M 1.2G
Swap: 0B 0B 0B


They are running a custom build of Debian Stretch (9) on a 64-bit arm chip. It is a full linux system. This does not apply to the Cat. 1710, which would require it's own secure CPU/FPGA for atmos processing.

I understand the frustration around not wanting to reboot equipment weekly, but I'd like to point out two important reasons to make sure it happens.

1) Software bugs causing memory leaks that lead to the system running out of resources
2) Cosmic rays flipping bits (See Toyota/Belgium Election results)

Both of those issues have more impact the longer the box is running. The CP950 is more capable than its predecessors, but also runs more software to make it more capable.

I do find it strange that using the HDMI input causes instability. It is possible that a low-quality cable is causing a large amount of errors on the link and that soaks up the limited resources of the CP950 as well. Hopefully Dolby has some more information based on the logs

[Marco Giustini]

I don't think data centres reboot their servers weekly It's a matter of developing resources I reckon. The 950 is still a niche product so there won't be a massive team of people behind it. And when it comes to software it's always a matter of priorities. If an issue can be prevented by rebooting the server once a week, then in the cinema world it's a low priority one I suppose!

[Marcel Birgelen]

Modern datacenters have thousands of servers and ten thousands of VM instances or containers. A lot of them reboot pretty regularly due to the never-ending stream of software updates... But we do have a bunch of servers with serious uptime. I wouldn't want my VM hosts to go bonkers every week... Those machines do have ECC memory though, all data to disk should be checksummed, so cosmic rays SHOULD usually be taken care of.

I agree with Marco that professional hard- and software should not need to be rebooted every now and then, just because the software on it is essentially defective. But yeah, that's what we're at... We live in a world where everything is constantly in alpha and beta state.

There is not a single party to blame for this, but one big influence has been a company I've hated with full motivations ever since: Microsoft and their founders (a bunch of who'm apparently had an appetite for young girls...). One of Gates' quotes seemingly was "If you can't make it good, at least make it look good.".

I still remember how they shoehorned Windows 95 into production, which was, back then, one of the biggest commercial successes but technically one of the biggest technical shit shows ever since then. I still remember the BSOD live-on-stage while they were presenting Windows 98... For me, this was the beginning of the "consumer is the beta-tester" era, where it was suddenly normal to ship products that crapped all over you the moment you turned them on.

It's fitting how they delivered one shitty product after another, but to this day are still one of the biggest companies on the planet. Just look at the pile of heaping junk that is Windows 11? Or the steaming mess of a non-product that Outlook has become? Or the frustratingly incompetent piece of garbage called Teams? Or what about Microsoft Word, still not being able to correctly indent an enumeration... still messing around with simple things like where a header starts and where it ends in 2026? Has anybody of you ever had the "pleasure" of working with Azure? The most convoluted, inconsistent, slow-to-provision cloud platform on the world, costing 10 to 100 times more than the competition, yet EVERYBODY needs to put their shit on there? Just yesterday, Outlook/Office 365 was down for MILLIONS of users, the entire day... Nobody seemingly cared.

</rant>

[Gordon McLeod]

I took FORTRAN and COBOL in classes with punched cards. In the COBOL class, we'd punch our cards, walk over to the HP computer, drop the card deck in and push start to get a printout of our error messages. In that class, we had to write a simple accounting program. The instructor explained that "all you need to know about accounting is that credit goes on the right because it has an R in it." Of course, the common abbreviation for debit is DR, but he did not mention that. Another time, I took my program to him looking for help. He looked at it for a while and then said, "I'm sure glad it's your problem!".

Fun times!

When I was in school we used WatFor programing language (University of Waterloo Fortran) and punch cards

[Harold Hallikainen]

Speaking of required reboots, we have several Amazon Echo devices. After a recent software upgrade, they require a reboot at least daily for group playback (simultaneous streaming to multiple devices) to work. I just did the second reboot of the day....

[Marco Giustini]

I still remember how they shoehorned Windows 95 into production, which was, back then, one of the biggest commercial successes but technically one of the biggest technical shit shows ever since then. I still remember the BSOD live-on-stage while they were presenting Windows 98...

For those who don't know what Marcel is talking about: https://www.youtube.com/watch?v=w_aQLBVuZns

It's fitting how they delivered one shitty product after another, but to this day are still one of the biggest companies on the planet. Just look at the pile of heaping junk that is Windows 11? Or the steaming mess of a non-product that Outlook has become? Or the frustratingly incompetent piece of garbage called Teams? Or what about Microsoft Word, still not being able to correctly indent an enumeration... still messing around with simple things like where a header starts and where it ends in 2026? Has anybody of you ever had the "pleasure" of working with Azure? The most convoluted, inconsistent, slow-to-provision cloud platform on the world, costing 10 to 100 times more than the competition, yet EVERYBODY needs to put their shit on there? Just yesterday, Outlook/Office 365 was down for MILLIONS of users, the entire day... Nobody seemingly cared.

I've been a PC guy since Windows 3.1. I've always tolerated and sometimes enjoyed the periodic tantrum Windows had but now I feel the situation has got out of control. As you say, W11 is a gigantic pile of steaming poop, it's slow, unreliable, unstable. I have recently moved to macOS (let's not start a war here) and whenever I use my Windows machine, there is ALWAYS something.

Microsoft have recently promised to fix Windows but then they came back with "in order to fix Windows we're going to re-do the Start Menu" - oh, not again MS! ? Yes, it needs to be fixed but are you going to re-do the Start Menu for the n-th time in 20 years? ?

I can't find the advert I have in mind but you can go to 32:10 if the link below doesn't take you there. It's still relevant.

https://youtu.be/0eEG5LVXdKo?t=1931

Finally, on Microsoft Word:

https://www.youtube.com/shorts/26BDVgIXkTo

[Gordon McLeod]

For those who don't know what Marcel is talking about: https://www.youtube.com/watch?v=w_aQLBVuZns



I've been a PC guy since Windows 3.1. I've always tolerated and sometimes enjoyed the periodic tantrum Windows had but now I feel the situation has got out of control. As you say, W11 is a gigantic pile of steaming poop, it's slow, unreliable, unstable. I have recently moved to macOS (let's not start a war here) and whenever I use my Windows machine, there is ALWAYS something.

Microsoft have recently promised to fix Windows but then they came back with "in order to fix Windows we're going to re-do the Start Menu" - oh, not again MS! ? Yes, it needs to be fixed but are you going to re-do the Start Menu for the n-th time in 20 years? ?

I can't find the advert I have in mind but you can go to 32:10 if the link below doesn't take you there. It's still relevant.

https://youtu.be/0eEG5LVXdKo?t=1931

Finally, on Microsoft Word:

https://www.youtube.com/shorts/26BDVgIXkTo

My invoicing and accounting is still done on a old OS2 (OS2 Warp4) machine that I cant remember when was last rebooted

[Caleb Williams]

I don't think data centres reboot their servers weekly It's a matter of developing resources I reckon. The 950 is still a niche product so there won't be a massive team of people behind it. And when it comes to software it's always a matter of priorities. If an issue can be prevented by rebooting the server once a week, then in the cinema world it's a low priority one I suppose!

I mean, they chose the Electron framework to make gui components for the web interface and the front panel ui. Electron is huge, buggy as hell, and they even have a systemd service that watches for when one of the Electron UI components uses up too much memory and kills it. Spoiler, that happens regularly, (like every 5 minutes).

I also think another component of this is the fact that a lot of cinema equipment is actually an FPGA/CPU amalgamation, and is very different than what you'd normally think of as a VM/workstation you'd use every day. The cpu and supporting components run some flavor of Linux (for Dolby that's generally Debian), (for Christie S3 that's OpenSuse), etc. that handle basic networking and data streaming, but the real data processing happens in the FPGA. For the CP950 that makes some sense because an FPGA can handle a LOT more data simultaneously and with the extremely tight timing tolerances audio processing requires. The Linux system just runs the management suite that keeps the FPGA fed. One downside of using an FPGA is the extreme challenge of managing many simultaneous operations without creating race conditions that corrupt the data you're working on. With an audio stream a variation of more than a number of nano-seconds can render data in the stream out of order or otherwise corrupted. The same is true for content running through any media block processing video/audio assets.

The FPGA is likely reloaded with it's configuration at every bootup, creating a clean-slate to start from. It makes some sense that the chosen resolution to some of these issues is the periodic reboot, because of the impossible complexity of the FPGA programming and troubleshooting. It would be very difficult to narrow down exactly what caused the problem after more than a month of uptime, and it's just simpler to start fresh. The CP950 is a much less mature platform than the one used in cinema servers such as the IMS as well, contributing to it's lack of long-term stability.

In summary, FPGA's allow for extreme data throughput and accuracy, but are very difficult to program due to the complexity required of the application.

[Ioannis Syrogiannis]

[...]I have recently moved to macOS (let's not start a war here) and whenever I use my Windows machine, there is ALWAYS something.[...]

If I could have what I wanted, I would have only used a Linux distro, or I would have been able to keep updating the software of my Intel Mac, that I can't any more, or I would not have been forced to upgrade to Win11 (funny thing, I was under the impression that there would only be newer, up to date versions of Win10, and not any new Windows OS, from the moment 10 were out).
The hard truth for me to digest, though, is that proprietary software, hardware and closed "ecosystems" are never going to allow me to keep a computer or an operating system on which I will be able to work, as long as the hardware will be able to run, like Gordon implies.

And God forbid, if I need an on-board serial port, or a program that Sony decided to only support for Windows 7, or secure boot, or some Final Cut Pro version that was not messed up, or a laptop that will not need a dock to connect to a USB thumb drive, etc. etc.

That same "there is ALWAYS something" feeling I often get when I boot into Linux, or first install them, and (often enough) into Windows. Yet, I equally find tiresome the fact that, when you are looking for specific programs or utilities, or open source solutions, or even something as simple as a UCI Viewer application or a working ClairMeta installation that doesn't need something like Docker, "there is SCARECELY anything". Even more, compared to what is available as open source on other platforms.

I enjoy Macs, because -among other things- I like the UNIX side of them, but the days of the trouble-free, well designed system and applications are gone. At least when one needs to use more than what is already there when the system is bought.

Unfortunately, there is no safe or trouble-free platform that covers all our current needs. We have to accept the situation we live in. And that is the CP950 that is showing the Tux penguin when it boots and its necessity of rebooting.

I am contemplating buying another laptop, to replace my 11 years' old one that works, but doesn't speak the exactly same language as the new ones, and the battery of which I can't source to restore its autonomy, and it's really hard for me to decide which way to go. Especially if I want the machine to be used universally and to last for at least eight years . (Yes, of course, remote administration and virtualization saves the day!)

[Caleb Williams]

Apparently not all CP950's are equal. I just had to reboot one at a remote site that had been up since December 2025 and was only started having issues this morning during the first show of the day. I can't speak to the HDMI weirdness (only because we don't use it on the CP950), but with cinema/non-sync only programming they seem to have reached an acceptable amount of stability with the latest firmware. Other units at that site have been up for the same amount of time and have not needed to be rebooted yet