Projekte / Technologie
Kerberos - C64 MIDI Interface
MIDI Interface für den C64 mit PC/Mac Dateiübertragung und Flash-Speicher.
4.544 €
2.500 € Fundingziel
Projekt erfolgreich
02.12.14, 11:36 Frank Buss
All Kerberos cartridges, USB MIDI interfaces and cables have been shipped now, most of you should have it already. Usually delivery time is less than one week for Germany and less than two weeks for other countries. Please contact me if you don't have it until mid december. If you need another one, there is a special limited edition now with a black case: To be honest: the case manufacturer has no white cases anymore, so this is the reason for the black edition :-) But I have still both in stock at the moment.
31.10.14, 00:42 Frank Buss
Finally I managed to finish a first version of the flash cartridge disk implementation. You can save two D64 images to the flash of the cartridge and define the drive number from 8 to 11 for each cartridge disk. When you start a program from one of the 25 PRG slots, then the program can access the cartridge disk as if it is a normal floppy disk. At the moment only read access is suppported (so BASIC "load", "open" etc. work, and the KERNAL functions for assembler programs, like loading songs and instruments from the cartridge disk for SID-Wizard, but not "save"), but shipping will start anyway next week after some final beta testing, because write support will need some more months. It gets complicated to do some nice flash caching, floppy BAM allocation etc. all in assembler. You can update the menu system over MIDI for write support later, if you need it.
09.10.14, 08:31 Frank Buss
The client for PC/Mac to transfer files and change settings is finished now: Thanks to the tests and ideas of Gert, now it looks much cleaner and is easier to use. Currently I'm working on the cartridge disk emulations (I think I can provide two cartridge disks on the flash), which I hope to finish in a few days and then shipping starts.
26.09.14, 11:18 Frank Buss
There are lots of details and needs longer than planned. This is the current GUI of the PC/Mac application: My beta tester told me that it might be too complicated for the the two most common tasks, save something to a flash slot and run a program, and might overwhelm users. I think he is right and I'll add an "expert" mode for the additional features like KERNAL replacement etc. He also did a very interesting demonstration video for Cynthcart, which shows how to use it with the MIDI interface and how to use some of the old and new Cynthcart functions: And another cool video from someone who used an earlier prototype of the cartridge with Steinberg Pro 16: I hope I can finish the software in a few days and then start shipping the cartridges.
18.09.14, 04:58 Frank Buss
Nicely packed, 10 in each pack: I soldered all through hole parts for one board and did extensive tests and all is working fine. I need still a few days to finish the menu software, but then I can solder and flash the rest and shipping will start, hopefully next week as planned. Paul is busy fixing last bugs and implementing new features in Cynthcart, too, thanks to him and to Gert for beta testing it thoroughly! And there is a new SID Wizard version 1.7, which of course will be pre-installed on the cartridge instead of version 1.6. Check out for the details. An awesome example what you can do with SID Wizard:
08.09.14, 12:17 Frank Buss
A quick update: the delivery of the PCBs are delayed, because one resistor is missing (I used special 1206 size SMD resistors for the MIDI output, to avoid overheating, even if the output is shorted, like from a broken MIDI cable). But the PCB manufacturer expects that I get all PCBs on September 15. I need some days to install the software and do a full flash and RAM test for each cartridge, and to finalize the software, so shipping of the cartridges to you should be at September 22.
09.08.14, 03:26 Frank Buss
Next week I'll present the Kerberos cartridge on the Gamescom faire, on a shared booth from Schreibfabrik: I'll be there at least on Wednesday, but you can test the cartridge on all days at Gamescom. I will setup a small sound station, with a C128, a MIDI keyboard and an external synthesizer. Another good news: Now the cartridge works with the 2 MHz mode on a C128 in C64 mode as well. Some games, like Prince of Persia, uses this mode for acclerating calculations or flash access. Was some work to implement this feature, but with my own logic analyzer with an adapter board for the expansion port ( ) it was possible to measure the timings on different computers and for different memory access instructions, and then verify it with my CPLD implementation.
29.07.14, 18:43 Frank Buss
All details are discussed with the PCB manufacturer, but they need longer than expected. I will get the boards between August 26 and September 2. I think I can program, test and ship all cartridges then in one week.
25.07.14, 22:58 Frank Buss
The tl;dr version of this update: The hardware is tested, no bugs found, and the PCB manufacturer prepares the series production now. The software is coming along, now written in C, with assembler libraries. New features in the CPLD allows to use the cartridge on a C128 in C64 mode and for starting C128 programs without fiddling with jumpers or the need for different menu systems. The details: I ported the menu program from assembler to C with CC65, only the time critical parts are in assembler anymore, which makes it easier to write programs for it. First I implemented lots of tests for the hardware, like a full RAM and flash test and MIDI in/out/thru tests. But there was still some room in the CPLD, so I implemented some more features (and tests) : - RAM as ROM mode: now it is possible to use the RAM on the cartridge as ROM modules (in any combination, like ROM at $8000 only, or ROM at $8000 and $a000), instead of the flash (which is still possible) - software reset generator - not only the KERNAL, but the BASIC ROM can be replaced, too now. This is different from the usual cartridge replacement of $8000-$9fff and $a000-$bfff, because usually it is impossible to replace $a000-$bfff, only (emulating a ROM replacement), but I can do this with the CPLD by setting the EXROM/GAME line only when the address from $a000-$bffff are accessed and not from $8000-$9fff, for a fully transparent BASIC replacement - HIRAM detection for using the C64 RAM under the KERNAL ROM when in KERNAL replacement mode - the ability to override the LED state to turn them on (individually), instead of displaying the MIDI RX/TX state as in the default mode The RAM as ROM feature makes it possible to program the RAM with the autostart cartridge id for the C128 and then generate a hardware reset, which then starts the C128 mode and the code in the cartridge. So the Kerberos cartridge is now one of the few cartridges, which works in C128 mode as well. I'll use this feature to implement a PRG start in C128 mode, same as PRG starts in C64 mode. Nice side effect: no jumpers are needed anymore. The cartridge starts always in C64 mode on a C128, but if you want to start a C128 program, it does setup the external RAM and registers and jumps to the C128 by generating a reset to start it. In combination with the KERNAL and BASIC replacement feature, the RAM as ROM feature allows a quick turnaround time to upload a new BASIC or KERNAL to the cartridge to the RAM instead of flashing it all the time, in case you want to develop some BASIC or KERNAL extensions. The new HIRAM hack allows to implement a fully transparent KERNAL replacement. Programs can still use the RAM below the KERNAL ROM. Unfortunately this hack doesn't work on a C128 in C64 mode, because the address lines are buffered on the expansion port on a C128. But the floppy emulation will still work, if the program doesn't use the RAM from $e000-$ffff, and I'll think of some workarounds with trampoline code in the external RAM, which needs the internal RAM. Then all you have to do is to patch the JSR addreses to the KERNAL function to point to the RAM trampoline code. For all programs with source code this is very easy, so for example with the SID-Wizard you can use the full floppy emulation on a C128 as well, for example to load or save instruments or your composed music. BTW: I tested the EasyFlash emulation on a C128 in C64 mode and work without problems. Unfortunately Ubisoft doesn't allow me to pre-install Prince of Persia, but you can download it from CSDb and install it yourself, if you have a PC or Mac with a USB MIDI interface. I'll pre-install the EasyFlash SID collection on the cartridge. If you are a coder, then C makes it even easier now to write your own programs for the cartridge. I'll provide some libraries and documentation, for example to use the MIDI functionality. Here is a quick test using the current MIDI library, which implements a synthesizer: And this is how it looks like: Next step will be to finish the menu, implementing some more features, like a disk file browser in the menu system to flash programs from floppy or SD2IEC, or to transfer whole disks to and from a PC or Mac, implementing the floppy emulation, and writing more documentation.
05.07.14, 13:11 Frank Buss
I fixed some minor problem with missing traces and some missing resistors and this week I got the (hopefully) final prototype of the PCB and soldered all components: Works good so far, no manual jumper wires are needed anymore. The new schematic and all source code changes are in the Github repository. Another interesting news: Someone suggested to support EasyFlash CRTs. EasyFlash is a cartridge developed by skoe with 1 MByte flash memory. It is supported in VICE as well. There are some high quality software collections available for it on CSDb: So I implemented an EasyFlash emulation for the Kerberos cartridge (EasyFlash 1). Now it is possible to use the second mb of the two mb flash to store an EasyFlash CRT. I compiled EasyProg for it, with an implementation of EAPI for my cartridge, and tested it with a few releases on CSDb and it worked great, even saving and loading savegames and highscores were no problem. EasyProg loads the CRTs from a floppy disk or SD2IEC, but I plan to enhance my software so that EasyFlash CRTs can be flashed over MIDI, too, same as it is already possible for the other normal PRG slots on the cartridge. Next week I plan to do some more software and hardware tests, with more C64 and C128 and then I'll order all PCBs. The manufacturer will need about 3 weeks to produce them, so you should get your cartridges in August as planned. Today I'll play some more Prince of Persia for the C64 on the real hardware, just for stress testing the cartridge :-) the end of level 2 is really tricky.
05.06.14, 14:28 Frank Buss
If you missed the funding phase, you can now pre-order the cartridge here: I will ship pre-ordered cartridges after all crowdfunding supporters got their cartridgdes. The stretch goal for the hard plated gold edge connectors was nearly reached, thanks again, so I decided to do it anyway. You can read more about the details here: That's just the process description, I'm using a local manufacturer for the PCB ( ).
29.05.14, 03:42 Frank Buss
The repository with all source code which I wrote so far, Eagle schematics (you can view it with the freeware version of Eagle) and the board layout is public now: There are still two wires missing in the schematic, which I had to solder on my prototype, so I have modify the board again, but it is only a minor change, should be easy. The KERNAL replacement feature (without any additional line from inside the C64, just the cartridge in the expansion port) is already working, see this video: Notice the first line on the C64 screen :-) I'm using the same trick as EasyFlash, switching to Ultimax mode dynamically when the KERNAL space is accessed, and then switching back to normal mode. Now I can implement the load/save emulation to use the internal flash and finish the rest of the software. Another good news about Cynthcart: Paul, the developer of the Cynthcart program, told me that he plans to implement MIDI CC messages as well, so it might be possible to use a pitch-wheel or a rotary encoder to adjust the pulse width of a square wave oscillator and other parameters, for interesting live performances and easier SID configuration.
27.05.14, 12:43 Frank Buss
The cartridge is funded, thanks! Now I'll finish the software (besides the already working menu, I have some good ideas and suggestions from people what features it should have, like an additional file browser for SD2IEC integrated in the menu, some useful MIDI tests etc.) and prepare the production, I'll keep you informed of any progress. I'll open the github repository in a few days, after cleaning it up a bit. Planned shipping is in August.
26.05.14, 17:57 Frank Buss
Steinberg sent me a package with the manuals and the original disks of the Pro-16 sequencer software (the plus version with addtional "graphic editor" aka track editor). I scanned and OCR'ed the manuals (for full text search), copied the disks with KryoFlux, and prepared a PRG file which will be used for the cartridge. Already tested with the new CPLD version of the cartridge and works like a charm. Steinberg gave me the permission to release it independently from the cartridge as well, see for the full package.
22.05.14, 22:41 Frank Buss
The attached image got lost in my last blog posting, this is the new prototype:
22.05.14, 22:36 Frank Buss
I substituted the discrete logic gate ICs with one CPLD. This means no jumpers are needed anymore for configuring the MIDI emulation (Datel, Namesoft etc.), it is configured by software. The plan is to add a setting to the PC/Mac software to select which interface the software needs (can be different for each slot), which is then saved with the configuration info on the flash. Now there is only one jumper left, to disable the flash, if you want just the MIDI interface, or if you want to use it with a C128 in C128 mode. The new CPLD made a new 3.3V flash possible, which is now a 2 MB version instead of 512 kB. And I added a 128 kB RAM. My plan is to use the same concept for changing the KERNAL as Easyflash 3 does. Then the RAM can cache a block of flash. What this all means: It should be possible to emulate a floppy disk drive, for all programs which uses KERNAL functions, with read/write to D64 images in the flash memory. Needs still some work and the CPLD is nearly full, but I think I can do it. Reading/writing to the flash and RAM, the menu system and the MIDI interface are already working. And last but not least, I added two LEDs, which lights up if MIDI data is received or sent. Replacing most through hole parts with better but fewer SMD parts resulted in only slighty cost increase, but of course the price is the same for you. I hope the project gets funded, only 10 days left. Now it's time to tell your C64-friends about it. Same in German: Ich habe die diskreten Logic Gatter ICs durch ein CPLD ersetzt. Das bedeutet, daß keine Jumper mehr erforderlich sind um die MIDI Emulation zu konfigureren (Datel, Namesoft etc.), geht jetzt alles per Software . Der Plan ist, die PC/Mac Software zu erweitern, sodaß man das Interface auswählen kann, was die Software braucht (kann pro Slot unterschiedlich sein), was dann mit im Flash gespeichert wird. Jetzt gibt es nur noch einen Jumper, um das Flash zu deaktivieren, wenn man nur das MIDI Interface haben möchte, oder wenn man es am C128 im C128-Modus verwenden will. Der neue CPLD ermöglichte auch, einen neuen 3,3V Flash Baustein einzusetzen, der jetzt 2 MB statt 512 kB groß ist. Und ich habe noch ein 128 kB RAM hinzugefügt. Meine Idee dabei ist dasselbe Konzept zum ändern des KERNALs einzubauen, wie beim Easyflash 3. Dann kann das RAM einen Block des Flash zwischenspeicher. Was das bedetuet: Damit sollte es möglich sein, ein Floppy-Laufwerk zu emulieren, für alle Programme, die KERNAL Funktionen verwenden, mit Lese-/Schreibzugriff auf D64 Images im Flash Speicher. Ist noch nicht ganz fertig, und der CPLD ist auch fast voll, aber sollte ich schaffen. Lesen/schreiben zum Flash und RAM, das Menüsystem und das MIDI interface funktionieren bereits. Und zu guter letzt habe ich noch zwei LEDs eingebaut, die leuchten, wenn Daten empfangen oder gesendet werden. Der Austausch von fast allen bedrahteten Bauteilen durch bessere aber weniger SMD Bauteile führte nur zu einer minimalen Kostenerhöhung, aber der Preis bleibt natürlich derselbe. Ich hoffe das Projekt wird finanziert, sind nur noch 10 Tage Zeit. Jetzt ist ein guter Zeitpunkt, euren C64-Freunden von dem Projekt zu erzählen.
30.04.14, 23:19 Frank Buss
Now the project is in the funding phase and you can claim your rewards (more than one reward is possible, please choose the right shipping reward). Currently I'm improving the circuit, so that no jumpers are needed anymore for configuring the MIDI emulation and the MIDI-out/thru selection. And another claim is available: Cynthcart. This program is free, but I'm developing a MIDI interface with the author for it, which you can buy pre-installed on the cartridge for additional EUR 5. Last but not least, EA has answered my question, I'm allowed to pre-install one of my favorite old game on the cartridge, too, Archon 2 (see for a video of it, two player mode is really fun).

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