CUPS Dyesub Backends

This is my personal to-do list for printer-related tasks, encompassing both changes to Gutenprint ( and the CUPS backends (

IDTask TypeCategorySummaryStatusLast Edited
597Feature RequestCommon CodeAllow for aliases in backend names?New2018-02-22 Task Description

That would allow us to present a 'modern' name for the backend but still provide backwards compatibility.

eg: dnpds40 -> dnp_citizen or mitsu9550 -> mitsu9xxx or mitsup95d->mitsu_p9x

Another approach would be to make things more fine-grained.


596TODODNP/CitizenFigure out if Citizen CW-02/OP900II are closer to CX or...New2018-02-22 Task Description

...or if they need their own designation in Gutenprint and selphy_print.

It looks like they don't map entirely cleanly to either for avialable print options, but the real question is the firmware version tests for features.

595Feature RequestCommon CodeWhen trying to enumerate printers, don't block for a lo...Assigned2018-02-16 Task Description

This is a particular problem when we have more than one model of the same printer family attached, and one or more of them are busy doing something -- but we can't query the serial number when the printer is claimed.

This may require a two pass approach -- first try to probe everything with minimal timeouts.  If we don't succeed in finding the one we want, re-try the probe with longer timeouts.  In both cases, we shouldn't report a failure until we finish walking the entire list.

592Feature RequestOther printersInvestigate Sony UPCX1New2018-01-28 Task Description

300 dpi, 4" or 5" wide media.

Not sure if it uses sheet or roll media.

591Feature RequestOther printersInvestigate Kodak DL2100New2018-01-27 Task Description

It's a duplexing "electro-photographic" (AKA laser) printer @600x1200dpi.  They rarget photo books and calendars with it.


Appears to be a rebranded version of the Oki C712.

590Feature RequestOther printersInvestigate Kodak D4600 / Mitsubishi CP-W5000New2018-01-26 Task Description

Duplexing 8x12" models, capable of cuts along both axes.

 589 Bug ReportMagicard family Fix 8bpp->6bpp color scaling Closed2018-01-04 Task Description

Right now we just shift the color data over by 2bits.  It looks like that's naive; it looks like we need some sort of gamma-aware 8->6 mapping on a per-channel basis.  This may require Gutenprint to spit out RGB data, and we perform the YMC conversion at the same time we apply gamma?  (not unlike the Mitsu D70 family..)

The printer's "gamma curve" settings don't seem to have any major effect.

It's also possible that my printer's head is just plain shot (there's already a bad row of pixels..), and that everything is actually fine.

588Bug ReportMagicard familyRegistration/Alignment issue with Black planeNew2018-01-04 Task Description

K extraction appears to work well, but when printing there's a registration problem.  The black layer appears to print several pixels higher than the color layers.

I'm not sure if this is something that needs a fixed offset applied, or is something that can vary printer-printer.

 587 Feature RequestMagicard family Figure out Magicard Duplex and Mag-stripe encoding. Closed2017-12-16 Task Description

Support is in for basic stuff, but it's not clear how to proceed with Duplex and Mag-stripe stuffs.

586TODOCommon CodeAdd JSON outputNew2017-11-24 Task Description

This might not be feasible in a general sense due to the need to interact with CUPS.  But it's worth investigating.

585Feature RequestOther printersAdd support for Zebra or other ID card printers.Assigned2017-11-24 Task Description

 584 Feature RequestOther printers Support Magicard Card printers Closed2017-11-24 Task Description

A backend's in place that can read the printer status but it doesn't parse/send over jobs yet.  Still haven't figured out the image dara format.

 581 Feature RequestCanon Selphy CP/ES Add status query to Canon Selphy backends Closed2018-01-04 Task Description

Query printer status -- eg loaded paper type, error codes, and whatnot.

The raw data is already there, but it would require a different code path to parse things for human output.

580Bug ReportCanon Selphy CP/ESDetect when on battery power and handle it gracefullyNew2017-04-11 Task Description

User reported the CP800 failed to print when on battery power, turns out one of the status fields changed causing us to fail.  I believe that's resovled for the older SELPHY CP models, but the newer ones (including the CP790) and the ES series are likely to have a similar problem.

Not sure what can be done about this without getting the battery and experimenting...

 577 Feature RequestMitsubishi MedSci Add ability to query status from cmdline Closed2018-01-08 Task Description

We don't get much info, but we can at least find out if any errors are pending, and if the printer is busy..

576TODOMitsubishi MedSciInvestigate P91DWNew2017-03-23 Task Description

There's a USB and Parallel version.  Might be worth trying to get hold of a USB model, but can't really justify buying one.

575TODOOther printersInvestigate Sony B&W Thermal MedSci models New2017-03-27 Task Description

UPD-897MD, UP-X898MD, and so forth

the UP-D898MD appears to be superficially similar to the Mitsubishi models, complete with the 1280 pixel print head (maxing out at 1280x4000ish) and similar adjustment knobs. They may have the same engine under the hood, but they're not likely to be semi-compatible with the Mitsubishi models.

 574 TODOOther printers S6145 -- don't generate an OC layer if not needed Closed2017-03-30 Task Description

And don't bother sending it over unless it's a matte print.


Actually I think the library already handles this okay, but we still have to allocate the space and generate things regardless.  A waste of CPU cycles, but otherwise harmless.  Probably not worth doing without direct access.

573Feature RequestShinko CHC-S6145S6145: Have Gutenprint generate planar YMC directlyRequires testing2017-11-24 Task Description

That way the backend won't have to do the conversion, saving some processing overhead.

(Re-purpose an unused field in the header, and clear it afterwards.  Not unlike how the D70 backend does it!)

572Feature RequestMitsubishi MedSciFigure out how to set printer sharpening on the P95DNew2017-03-23 Task Description

The P93D supports it via the driver, but the P95D doesn't.  However, it can be set on the front panel..  It's in there somewhere, I bet.

Bonus -- Can we enable/disable iserial support?

571Feature RequestKodak 605Check for error statuses in the Kodak 605 processing lo...New2017-03-23 Task Description

We don't check any error codes at all.  In part because I don't know what's an error and what isn't.  With access to a printer this would be a lot easier..

 570 TODOCommon Code Iterate through all printer interfaces and altsettings  ...Closed2017-11-08 Task Description

We assume that the first interface/altsetting is what we need.  And, for that matter, that the first set of endpoints is what we want.

569Feature RequestMitsubishi CP-9xxx familyFigure out image processing algorithms for CP-98xx fami...Assigned2018-01-22 Task Description

They're an older-generation of the D70 family's.  Data tables are unfortunately embedded inside the drivers, which makes this a lot more challenging. Sigh.

(If nothing else, simply obtaining the RGB->YMC conversion/gamma tables would make the printers immediately useful..)

568TODOMitsubishi CP-D70 familyFigure out how to set the "user string" that's supposed...New2017-03-23 Task Description

There's a proper serial number returned so that's not so critical.

567Feature RequestMitsubishi CP-D70 familyFigure out how to query the overall job status on the D...New2017-03-23 Task Description

The command I know about just returns an endless status stream..

 566 TODOMitsubishi CP-D70 family Dig up firmware update package for CP-K60DW-S 1.04 Closed2017-07-19 Task Description

Then add the checksum to the backend so we can complain if the firmware is out of date.

565Feature RequestMitsubishi CP-9xxx familyCP-9600 family supposedly supports some sort of multicu...New2017-03-23 Task Description

This references a lot of firmware images, including 'Firmware CP9600 for 13x18,10x15(x2),11.5x15(x2).zip -- None of those sizes are covered in the current Gutenprint code.

564Bug ReportMitsubishi CP-D70 familyD70 fails to print on Raspberry Pi systemsResearching2017-07-19 Task Description

We get failures when sending the printjob to the printer, with libusb reporting USB timeouts at random places.  There seems to be no consistency to when a transfer fails.  Using a hub makes this worse.

I have an additional two reports of a RPi3 failing USB transfers to a D80 when there is no ethernet cable plugged into the interface!


The K60/EK305 appears to work okay.

563TODOCommon CodeSupport more printer attributesNew2018-02-16 Task Description

...especially the printing started/finished stuff.


 562 Bug ReportMitsubishi CP-D70 family Quality problem with the D70 family image processing li ...Closed2017-03-19 Task Description

It's most obvious when printing something with a deep black; you'll see it bleed past a bit.

It's worse in Fine, better in SuperFine/UltraFine.


561Feature RequestCommon CodeUse USB VID/PID instead of 'UNKNOWN' when we can't dete...New2017-03-12 Task Description

 560 Bug ReportMitsubishi MedSci P95: Failure to parse printjob when 'clear memory' is e ...Closed2017-02-12 Task Description

The problem is that two commands of different length use the same 2-byte prefix.  To distinguish between them we'll need to read the third byte, but only in that case as there are some commands that are only 2 bytes.


Or re-architect the command parser to handle this without extra hacks.

 559 TODOCommon Code Pull copy generation out of backend Closed2017-11-09 Task Description

Gutenprint 5.2.12 now supports generating multiple copies.  The backend shouldn't do it internally (nor should it print hte PAGE output)

 * Printers that have a copy count in the job header -- use the printjob number if it's >= the cmdline copy one.

 * Otherwise, backend should loop and generate copies.

 * If *not* invoked from within CUPS, print the PAGE output.

558Feature RequestOther printersInvestigate new Sinfonia S3 (CHC-S2245)New2017-03-19 Task Description

It's not available yet, or even announced, but I found a site listing it for preorders.


557Feature RequestOther printersInvestigate Sony DPP-FP30New2017-03-23 Task Description

And other members of that consumer printer family.  Not sure if they're still relevant commercially.

556Feature RequestSony UR-DP150/200status queries and flow controlNew2016-12-19 Task Description

It would be really nice if we could figure out how to query the UP-DR200's printer status, media counts, flow control, etc etc.

 555 Feature RequestMitsubishi MedSci Investigate Mistubishi P93 and P91 Closed2017-02-10 Task Description

Now that the P95 is in solid shape, I don't imagine that the other models would pose much of a problem.

 554 Feature RequestCanon Selphy CP/ES Get USB IDs for Canon SELPHY CP820 Closed2017-03-27 Task Description

They're needed by the 'canonselphyneo' backend, and I've been unsuccessful in scrounging them up. 

 553 Bug ReportCanon Selphy CP/ES Back-to-back CP1200 prints hang the printer Closed2016-12-03 Task Description

User repors that back-to-back prints cause the printer to hang.  This is with the stock USB backend that relies on standard flow control.

Fixing this will first require printing stuff back-to-back under Windows and sniffing it to see if there's any flow control in use.  Bleh

552Feature RequestCanon Selphy CP/ESWrite network backend for CPnP printersAssigned2016-12-22 Task Description

The 'selphy_go' code showed how to detect CPnP models and send JPGs over to be printed..

Using the CP900, I discovered how to send raw YMC data over CPnP.  This means we can write a native CPnP CUPS+Gutenprint backend for that model.

Unfortunately we won't know if the newer selphyneo models support non-jpeg CPnP printing -- The Windows driver uses WSA/WSD and Macs appear to use AirPrint.  The only way to find out is to write it first.

 551 Feature RequestMitsubishi CP-9xxx family Add CP-9600, CP-9800, CP-9810 support to CP-9550 backen ...Closed2016-12-03 Task Description

They're all closely related, so this is the right thing to do.

550TODOMitsubishi CP-D70 familyVerify support for D707Waiting on Customer2018-01-04 Task Description

Code's complete, but needs to be verified.


548Feature RequestShinko CHC-S6145Add support for Sinfonia CHC-S6145-5A (aka CS2-c)New2017-11-24 Task Description

It's a card-sized variant of the CS2.  89mm cards of various widths.

 547 Feature RequestCommon Code Add printer icons to Gutenprint Closed2016-10-13 Task Description

*OPIcon Manufacturer: "...."

*OPIcon ModelName: "...."

The data is UUEncoded/Base64 64x64 PNG or an SVG image.


I see printers.xml gaining a reference to the image files, and the PPD generation code reading the image, encoding it, and shoving it into the PPD.  It's a minor thing, but nice to have.


 546 Feature RequestCommon Code Extend Gutenprint's option infrastructure to allow for  ...Closed2016-09-09 Task Description

The work's done, but it's not merged yet.

 545 Bug ReportCanon Selphy CP/ES Figure out how to make the CP820/CP910/CP1000/CP1200 ac ...Closed2017-04-21 Task Description

It would be *really* nice if we could figure out a way to ditch the component Y'CbCr output and use native YMC, but it's likely that only Canon ultimately knows if that's possible, and how.

 544 Feature RequestDNP/Citizen Investigate and support new RX1HS Closed2016-10-07 Task Description

DNP's introduced the RX1HS to replace the RX1.  I'm told it's the same hardware, but requires different media.

Initial investigation shows it's added some features that were first introduced in the DS620.  (iSerial support, maybe more).  Backend changes will likely be minimal, but Gutenprint may require a tweak to expose any new features.

Further work will have to work until I get documentation or access to a printer.

543Feature RequestOther printersIntestigate Color Sony MedSci modelsNew2017-03-23 Task Description

 UP-DR80MD, UP-DR25MD, UP-DR23MD, and so forth.

541Feature RequestMitsubishi CP-D70 familyInvestigate CP-D90DWWaiting on Customer2018-02-23 Task Description

It looks like it's an evolution of the D70 family, with one critical exception -- it appears as if the color/thermal compensation is performed in the printer instead of the driver!

540TODOOther printersInvestigate Fuji ASK 2000/2500/4000 (aka Nidec Copal DP...New2018-01-27 Task Description

They are all related; The 4000 is an 8" version, and the 2000 is an older, slower version of the 2500, both 6" models.


All are rebadged versions of Nidec Copal printers -- ASK4000 == DPB-4000C1, ASK2500 == DPB-7000, ASK2000 == DPB-6000

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