kgallen

There seem to be conflicting usage of the I2C bus from the uC. On the 640 this bus is used to implement the keyboard interface. On the S50 it's used via an I2C buffer chip to implement the PC-Link. So from what I can see keyboard vs PC-Link are mutually exclusive and there is likely different firmware in the uC for each variant to account for this. FWIW the I2C buffer chip, IC800 is a standard NXP part, P82B715TD .

Careful otherwise you're going to become some intermediary seller for us in the UK!

It's perfectly possible this comes down to cost and device availability. If Sony have a number of population options in their products they can go with the flow and choose the cheapest option at the time of build, or are more robust against yield issues on a particular part. Silicon memory faults are the most likely cause of device yield dropoff, particularly on-chip flash which will require different processing steps and different silicon implants in the wafer fab compared to SRAM and random logic which are more "standard". Mixed-process devices are more problematic (and it's very impressive that the Sony CXD chips have on-chip DRAM mixed with "normal" VLSI digital logic, SRAM and probably even some analogue interface circuitry - very impressive for the year, and Sony are "fabless", so they don't have the luxury of in-house processing they can tune and tweak like Intel). If all machines of a given model have the same device population then that would indicate an engineering requirement. Where there is population variability it probably is a decision made on BOM cost at the time.

The external Flash chip, IC2, is padded out but is is populated? In my 440 the chip is not populated, but IC2 is shown on both 440 and 640 schematics. I see similar in my two MDS-E10's - one has the external Flash chip populated the other doesn't. I wondered why this is. Is it CYA for when the firmware grows too large for the flash inside the uC? Or maybe a cost option, external flash might have been cheaper at some point than the next uC up the scale with larger internal Flash? What I'm saying, is the population of this Flash chip really feature dependent or just an evolutionary precaution or an option for BOM cost tradeoffs? i.e. having the flash or not, is not necessarily an indicator of functional capability. In the S50 SM, page 40, the schematic outlines a few components in blue, and some not. The external Flash, IC2, is not outlined. The footnote says "There are a few cases that the part isn't mounted in model is printed on diagrams" (sic). In fact on p42 of the S50 SM, which is the uC sheet, the external flash is not drawn. S50 uC=M30805MG-211GP [144 pin QFP], 440/640=M30805SGP [144 pin QFP]. I'd need to investigate the uC datasheet to see if there is enough information in these part codes to indicate a different variant of the part is selected. S50 timeline suggests it came out a few months after 440/640 so it's possible Mitsubishi revised their uC family slightly and Sony started to order using the new part code - when under the hood they had the same requirements on the uC for internal RAM and flash etc.

It is, so what the heck are you doing up on the Forum - get some shut-eye! :-P

Assuming one could get the right parts especially the connectors then the PCB pads are there for the taking. Is this an S50 option? So the hardware is probably do-able in a fashion (connector bodged onto the back panel for instance). The firmware might be the issue. I don’t know if they load all these machines with the same uC firmware. There are pins on the uC labelled ‘model’ but these don’t seem to be tied either way on the 440 or 640 - often 0R links are used to set a binary code. My 440 knows it’s a 440 (from info in Service Mode) but it’s not clear how it knows that unless it has a fixed 440 firmware load. (@sfbp are you able to break this out and create a new topic with the last couple of messages here to preserve the OPs thread?)

It is indeed! I have the lid off now and have been looking around this for a while! (Initially looking at the parts for optical out). Indeed the board is mastered for the 640 and I also see silk screen for the S50 front panel connector. I'm just comparing and contrasting the 440 and 640 schematics wrt the PCB build. I was just eyeballing the headphone amp section fitted for the 640 and not the 440. Good deduction young man @NGY! :-) (Waaaay off topic but this machine plays properly but has record issues. The OP is adjusted to spec with the LPM-1 and the IOP [using said MDM7 jig]. Tracks will record in that there are no errors and TOC is apparently written - track can be titled! But whilst the new track number is detected the new track can't be read - deck (this or E10) can't retrieve the track time or play any audio. OWH measures out at 1.8 ohms so is not open circuit. With the lid off trying to play the track I can see the OP constantly seeking around where the track start is. I've just recorded some tracks at IN, MID and OUT and these all now read, so an intermittent issue. Sometimes it seems the OWH head drops slowly, so maybe this is a lubrication or not-used-for-a-long-time issue - although this is consistent and only happens when the OWH drops to write the TOC - it's like it's sneaking up on the disc slowly to avoid frightening away the track data that doesn't yet have all of the TOC pointers in place! Interestingly if the TOC is clean and then I title the track only, then the OWH whacks straight down. But if I record audio, title and then eject to write TOC, the OWH drops slowly again. This seems repeatable and deliberate. Hmmmm... <cheeky> Ideas welcome! </cheeky>)

Sorry @R_V it seems I owe you a reply here! There are two ribbon cables that go from the main board to the drive. They are about 25mm wide and very thin. Here is a photo showing them, see the top left of this photo, circled - although this picture is from a 440 or 480, I don't recall. Yours will be in a slightly different place no doubt, and the main board will look different, but you're looking for thin ribbon cables that look like this whatever the details inside your particular machine. In this picture, ignore the narrower one in the middle of this picture, that goes to the front panel. You might have one also in your machine but this one is not of interest at this point. The way to remove and insert these is to use both hands, with each end of the ribbon between thumb and first finger, holding down as close to the connector as possible. Pull up gently, keeping square and re-insert with a firm but gentle push down, again keeping the ribbon square with the connector. Total travel is only about 3mm. Overall, where did you get to with your two machines?

Whatever, we're now "HOT HOT HOT" so @JonasE gets some kudos for his thread :-D (ps Sorry @zedstarr for waking you from your MD slumber! Let's ping you again :-D )

4 of these are "for" the kids - I bought a pair but had issues with them (so are now sitting in a drawer) so ended up buying another pair that thankfully work. The only portable I use is my MZ-R700 which I've had from new (maybe 2000), which I have in the office at work [not been there for some months now with the C* thing] with my stack of "legacy audio media" as my colleague call my pedestal drawer full of minidiscs...

They are Class II, nothing to test really. Inspection is key. As these machines have transformers then you could do an insulation test with the probe on the metal case, but there is little to be gained with this, you can spot the main faults with your in-built test equipment (your eyes). Of course, I take care of my equipment and ensure it is in a safe state. This is common sense. This kit is only really formally inspected and tested because (a) I'm a pedant and like to button things up (b) strictly it's needed for me to take my kit into the halls we use for our shows. No I don't "PAT test" my house equipment, I'm not that bad! (Well I might if I did a repair to something where putting it on the tester makes sense). I don't want to talk about "PAT testers". Such discussions can be better covered by others, like BigClive.

Nobody yet has pointed out the clocks are different! :-D

Yes, other equipment was done on 1/Jan. Jeez, it was cold in the shed! Such is life... how sad!

No hijack - nice to see a few friends on the thread, seems I'm being watched (eh, Chris... ;-) ! Eeeek! Actually my apols to the OP, it seems I'm the one heading towards a thread and project hijack!

So yes, as I was saying before I got my cover blown... I have two E12 joined in a rack (well only ‘cos I haven’t added the third ;-) :

Oh darn, the boys have been keeping an eye on me this morning :-D I think most are listed on my profile (I think...!). But then you lot keep encouraging me to watch more on eBay!

I want to join the two E12s with coax SPDIF and a-n-other cable and do a disc clone, audio and text. I could do this with two MDS-JE530 machines if I connect coax or optical for the audio and the two A1 ports. However I only have one 530 (in amongst the maybe 20 machines I have, shhhhh :-)

Seems like the E12 has CTRL-S which is input only, doh. So that means I can't link two E12's by CTRL-S. I thought this was a newer version of the Control-A1 I have on my MDS-JE530 but it seems not. That means I need to find another way to get the track names across. I was looking for another 530 but the prices have gone through the roof... So maybe I can do the name copying with your software magic and the E12's after all?

I've got one (and just bought another as it happens!). Not sure if you'll get much inside in addition to the existing stuff. A small Xilinx Spartan on a custom board at best? Let us know what you're up to with it (on a new thread).

It was @zedstarr's and @NGY's fault, they put me through the mill with it!

Did you see our work here (page 2 on)? This could be done in a different way in FPGA but there is some analysis and info here (and the final FSM) that will be useful information. The clock recovery (not in the scope of the below thread) is one of the hardest parts - possible you could integrate part of this into digital logic in the FPGA and maybe even use one of the on-chip DLLs (depending what family you're using), or use an external PLL chip like the various Elektor designs of old. ETA: MDS-E12 has fully copy-bit control, so a "killer" is not needed. Don't know about your MDS-E11.

I would like to be able to make an MD disc clone (so I can create a backup disc of a master with SFX/music on for theatre) - well at least copy all audio and title tracks. Possibly I can already do this with the SPDIF plus CTRL-S link. But it was a thought, I'm intrigued by the control possibilities...

No problem! Personally I'm not too worried about that COMBINE command, but I'm happy to try and help debug your implementation of it! I'm interested what can be done over this interface, particularly how I might either link two MDS-E12 together or if I could create an interface to my lighting console - so being able to trigger the MD players from a DMX or Art-Net or sACN command. This of course would require me to use something like a Raspberry Pi to interface between the two, but from the software side I'd be interested if your code could run on a Pi (of which I know relatively little, generally being an Arduino user).

I have a PC with DB25 serial port running Win7, so I'll be happy to give this software a go with my MDS-E12 machines (assuming I can find an RS232 DB25-DB9 serial lead!). Kevin

Well I've been playing about with my MD-350 for a while now. Of the very many I've tried, I can’t seem to find any sort of button combination that gets me in to any Service Mode (holding buttons in whilst turning on with the power switch[*] and continue to hold buttons for a while longer). I now seem to have got a little distracted with playing with SP/LP2/LP4... so that's today gone! [*] The MD-350 has a "proper" clunky on/off switch, not a standby/on like the domestic Sony MDS decks.