In the reference manual of the Nexys 4 in Pag 10 you can read the USB part. "The Auxiliary Function microcontroller hides the USB HID protocol from the FPGA and emulates an old-style PS/2 bus. The microcontroller behaves just like a PS/2 keyboard or mouse would. This means new designs can re-use existing PS/2 IP cores. Mice and keyboards that use the PS/2 protocol use a two-wire serial bus (clock and data) to communicate with a host. On the Nexys 4, the microcontroller emulates a PS/2 device while the FPGA plays the role of the host. " In Short, the microcontroller PIC24FJ128 of the Nexys 4 read the data from USB but the Mouse and Keyboard have to be COMPATIBLE with PS/2 protocol. So, any USB keyboard compatible with PS2 protocol will work.
THANK YOU for this added information. It explains so much and also makes it easier to understand and identify why/which keyboards will work. Pinning this comment!
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The community currently experimenting with a less expensive Wukong FPGA which will drive the price down more. What parts of the MEGA≡65 do you feel are unpolished?
I think that may be a more advanced model? Part number on mine says P/N JK-0800EU-0/02. I’ll see if I can find the thread on Discord and provide my lsusb output. I also have a list of some other keyboards that don’t work :(
Very interesting video and glad to see the project working. I appreciate that you mentioned perhaps the main limitation, the inability to connect a joystick, be a DB9 or USB joystick. I'm also curious if it will use a mouse for GEOS, although it seems unlikely. So, while this is attractive as hobbyist and for the developer, i think people wanting to actually play any games on it will need to save for the actual Mega 65.
Until I can find a mouse that works, I won't be able to test GEOS and honestly without two USB ports, it is limited, so I go back to the possibility to add a 9 pin DIN via a PMOD but again, that requires development of the bitstream and I'm not sure how much longer the Nexys will receive specific hardware support.
If you use a Keyrah interface You can connect the c64 keyboard as well as a DB9 joystick. Also the Nexys 4 (the non DDR one which is exposed here) is not for sale anymore. Also the Nexys 4 DDR has been rebranded as Nexys 7. The Mega65 team support and will keep publising the Mega65 for the 3 Nexys boards. The main difference between these 3 boards are the following : Basically the Nexys 4 (the non DDR one) could use its additional memory as Attic RAM because the MEGA65 team has implemented the code (but it has been disabled so far). For the Nexys 4 DDR / Nexys A7 there's no implementation at all for memory expansion since it would require the implementation of a DDR memory controller which has not been done so far. So if you can manage to get a Nexys 4 (non DDR) from an old stock this is definitely the card to get. Also keep in mind that depending on the Nexys Board you get, you must be very carefull with the core version you use, i.e., do not flash a Nexys 4DDR/NexysA7 board with a core made for the Nexys 4 non DDR and vice versa. There's no garantee it won't damager your board.
The non DDR is available here: digilent.com/shop/nexys-4-artix-7-fpga-trainer-board/ Thats the one you are talking about. Correct? I'm going to play with the Keyrah. I have one available that I can test with the Nexys.
@@OlivierSimpleLife @retroCombs that would be an interesting test. Of course it also depends on how the keyrah is perceived by the board and if the core is prepared to use it. If it acts as a USB hub the board may not be able to use it at all.
@@retroCombs Indeed that's the one, only 13 are in stock and definitly so far, even if the code has been disabled in the core, it's the only one which has an implementation for ATTIC RAM. This means that potentially (unless a DDR controller is implemented in the core for Nexys4DDR/NEXYSA7) it's the only board which can take advantage of the additional memory.
Its probably n-key rollover that's messing with the keyboard success since that either works with proprietary drivers or emulates an unreasonable number of usb hid devices to work and overcome the usb hid rollover limits. Some keyboards such as an older Corsair board i have have a bios compatibility mode that disables n-key rollover but the stock firmware seemed to have a bounce problem after updating the firmware it worked much better without proprietary drivers.
Looks like youtube deleted my comment. Just wanted to follow up my previous comment and say I found in forum64 and youtube evidence that keyrah works with the Nexys to provide joystick input, but creates a possible issue in that it means a C64 or C65 keyboard is then needed. Even if one can find a C64 keyboard, then there would be the question of whether not having the additional C65 keys would create a problem for some of the functionality, such as selecting core, etc. You can find a video called "mega65 with keyrah v2"
Thanks for sharing. I have a Keyrah. It could be a fun experiment. I also gave a spare Plus/4 and VIC-20 keyboard, but like you wonder how well it would work with the missing keys. Thanks for sharing and for watching! Not sure what happened to the original comment. Did it include a link?
@@jalzate Agree! I checked to make sure I had the moderation settings and comments with links are allowed. Very odd. Thanks taking the time to repost though.
Not sure I understand the question/statement fully (apologies). Do you mean the MEGA65 includes some proprietary hardware? If so, yes. The board is a custom implementation of the Xilinx FPGA.
@@retroCombs Yes, my apologies, the statement was not clear . Based on what I understand from the video the ROMs are closed source . And maybe the sources for the fpga too. Am I right? If this is right then this changes my vision about the project, added the fact that the machine is quite expensive too.
@@MrRobbyvent That is correct, but there is an open ROM and you can patch the original C65 .ROM. I should probably add more information on the companion blog post about these ROM types or create a separate post/video.
Bitstream is not closed. The .ROM, due to license, is not available without a MEGA65 purchase; however, the is an open ROM available and you can patch the original C65 ROM.
@@codingwithculp I feel your pain! Still, this is a fun project. You'll have a good time with it while you wait. I love my Dev Kit, but this is a more portable version.
@@retroCombs That link works, many thanks! Btw great Video, i will join when the nexys4 boards are available at my german online shop. Keep up the good work !
@@retroCombs I will clearly end up buying one of these, spending all this time just re-watching these two videos! The level of "cool" this thing eminates is unreal. The inclusion of BASIC and PETSCII keyboard, my oh my I need a glass of cold water over the head 🥛😎
@@DailyCorvid If you do, you must let me know how it's going. There's currently work on an add on board that will add a joystick port. Something I want to attack soon.
I've not been able to get one working yet but there may be some updates coming that fix this. Not timeline though. Of course, I haven't tried this in awhile either. Might need to give it another shot.
200 is still to much for a System that have Like 0 Software, 0 Brands, only some dreamers behind. So you will only use the C64 Mode at end. 10 Mins 65 fun then only C64 what every calculater can Emulator today.
Check out files.mega65.org. There's a lot of fun software to explore with more on the way. For me, it's not about the package software but the upgraded BASIC 65. It's a blast exploring this language again after 40 years. I get it. This project isn't for everyone but for hard-core Commodore fans, like me, there's a lot of fun to be had.
In the reference manual of the Nexys 4 in Pag 10 you can read the USB part.
"The Auxiliary Function microcontroller hides the USB HID protocol from the FPGA and emulates an old-style PS/2
bus. The microcontroller behaves just like a PS/2 keyboard or mouse would. This means new designs can re-use
existing PS/2 IP cores. Mice and keyboards that use the PS/2 protocol use a two-wire serial bus (clock and data) to
communicate with a host. On the Nexys 4, the microcontroller emulates a PS/2 device while the FPGA plays the
role of the host. "
In Short, the microcontroller PIC24FJ128 of the Nexys 4 read the data from USB but the Mouse and Keyboard have to be COMPATIBLE with PS/2 protocol.
So, any USB keyboard compatible with PS2 protocol will work.
THANK YOU for this added information. It explains so much and also makes it easier to understand and identify why/which keyboards will work. Pinning this comment!
I just found your channel. You just earned a subscriber.
You made my day! Thanks for being the most recent subscriber of the day and hope you enjoy the content! Welcome to the retroCombs community! We've got a small but friendly group of retro-computer enthusiasts.
Great video! So useful and comprehensive.
Thanks so much. It was a blast to put together.
And with this hardware the internet engineering - price ratio is balanced again. Thanks for this video. The Mega65 is too unpolished for its price.
The community currently experimenting with a less expensive Wukong FPGA which will drive the price down more. What parts of the MEGA≡65 do you feel are unpolished?
In case anyone else is still looking for a working keyboard. Cherry KC 1000 JK-0800EU-0 worked for me ($15 from Micro Center)
And thanks for this video by the way 👍
And thanks for adding another keyboard to the list of working models!
Looks like $25 at Amazon. This one? amzn.to/3z4GXe4
I think that may be a more advanced model? Part number on mine says P/N JK-0800EU-0/02. I’ll see if I can find the thread on Discord and provide my lsusb output. I also have a list of some other keyboards that don’t work :(
Just saw that the one I linked to had a card reader. Rats Close but no cigar.
Very interesting video and glad to see the project working. I appreciate that you mentioned perhaps the main limitation, the inability to connect a joystick, be a DB9 or USB joystick. I'm also curious if it will use a mouse for GEOS, although it seems unlikely. So, while this is attractive as hobbyist and for the developer, i think people wanting to actually play any games on it will need to save for the actual Mega 65.
Until I can find a mouse that works, I won't be able to test GEOS and honestly without two USB ports, it is limited, so I go back to the possibility to add a 9 pin DIN via a PMOD but again, that requires development of the bitstream and I'm not sure how much longer the Nexys will receive specific hardware support.
If you use a Keyrah interface You can connect the c64 keyboard as well as a DB9 joystick. Also the Nexys 4 (the non DDR one which is exposed here) is not for sale anymore. Also the Nexys 4 DDR has been rebranded as Nexys 7. The Mega65 team support and will keep publising the Mega65 for the 3 Nexys boards. The main difference between these 3 boards are the following : Basically the Nexys 4 (the non DDR one) could use its additional memory as Attic RAM because the MEGA65 team has implemented the code (but it has been disabled so far). For the Nexys 4 DDR / Nexys A7 there's no implementation at all for memory expansion since it would require the implementation of a DDR memory controller which has not been done so far. So if you can manage to get a Nexys 4 (non DDR) from an old stock this is definitely the card to get. Also keep in mind that depending on the Nexys Board you get, you must be very carefull with the core version you use, i.e., do not flash a Nexys 4DDR/NexysA7 board with a core made for the Nexys 4 non DDR and vice versa. There's no garantee it won't damager your board.
The non DDR is available here: digilent.com/shop/nexys-4-artix-7-fpga-trainer-board/ Thats the one you are talking about. Correct? I'm going to play with the Keyrah. I have one available that I can test with the Nexys.
@@OlivierSimpleLife @retroCombs that would be an interesting test. Of course it also depends on how the keyrah is perceived by the board and if the core is prepared to use it. If it acts as a USB hub the board may not be able to use it at all.
@@retroCombs Indeed that's the one, only 13 are in stock and definitly so far, even if the code has been disabled in the core, it's the only one which has an implementation for ATTIC RAM. This means that potentially (unless a DDR controller is implemented in the core for Nexys4DDR/NEXYSA7) it's the only board which can take advantage of the additional memory.
Its probably n-key rollover that's messing with the keyboard success since that either works with proprietary drivers or emulates an unreasonable number of usb hid devices to work and overcome the usb hid rollover limits. Some keyboards such as an older Corsair board i have have a bios compatibility mode that disables n-key rollover but the stock firmware seemed to have a bounce problem after updating the firmware it worked much better without proprietary drivers.
That's an interesting take. Wish we could get more keyboards working.
What nice infromative video
Thanks. Its a bit long and may not be for everyone, but if you want to try and build a MEGA65 with a Nexys, hopefully this will help.
Finally!
I know! Whew.
Nice but I am ok with the C64
TheC64 is a great device, as you can tell by the many videos I've created for it.
Will you update the blog post link?
Thanks for letting me know the link was broken. Not sure what happened, but all works now: www.stevencombs.com/mega65-nexys4
the bit file is no longer available for download. typical
Just saw in the Discord you found it: files.mega65.org?id=a2b3c6a2-be4c-4b98-9df4-2bc14df0f222
Looks like youtube deleted my comment. Just wanted to follow up my previous comment and say I found in forum64 and youtube evidence that keyrah works with the Nexys to provide joystick input, but creates a possible issue in that it means a C64 or C65 keyboard is then needed. Even if one can find a C64 keyboard, then there would be the question of whether not having the additional C65 keys would create a problem for some of the functionality, such as selecting core, etc. You can find a video called "mega65 with keyrah v2"
Thanks for sharing. I have a Keyrah. It could be a fun experiment. I also gave a spare Plus/4 and VIC-20 keyboard, but like you wonder how well it would work with the missing keys. Thanks for sharing and for watching! Not sure what happened to the original comment. Did it include a link?
@@retroCombs yes, it had a link to the video I mentioned. But come on youtube, it was a link inside youtube!!! :D
@@jalzate Agree! I checked to make sure I had the moderation settings and comments with links are allowed. Very odd. Thanks taking the time to repost though.
so the Mega65 project is closed in some components....
Not sure I understand the question/statement fully (apologies). Do you mean the MEGA65 includes some proprietary hardware? If so, yes. The board is a custom implementation of the Xilinx FPGA.
@@retroCombs Yes, my apologies, the statement was not clear . Based on what I understand from the video the ROMs are closed source . And maybe the sources for the fpga too. Am I right? If this is right then this changes my vision about the project, added the fact that the machine is quite expensive too.
@@MrRobbyvent That is correct, but there is an open ROM and you can patch the original C65 .ROM. I should probably add more information on the companion blog post about these ROM types or create a separate post/video.
Bitstream is not closed. The .ROM, due to license, is not available without a MEGA65 purchase; however, the is an open ROM available and you can patch the original C65 ROM.
You just caused me to spend about $250....
Awesome! Glad I could deplete your bank account. 😂
@@retroCombs Which pales in comparison to the $850+ I spent on the Mega65. But since it isn’t here yet……
@@codingwithculp I feel your pain! Still, this is a fun project. You'll have a good time with it while you wait. I love my Dev Kit, but this is a more portable version.
Hm cannot join discord channel, the invitation ist invalid.....
Try this one: discord.com/invite/5DNvESf
If it works, I'll update the blog post.
@@retroCombs That link works, many thanks! Btw great Video, i will join when the nexys4 boards are available at my german online shop. Keep up the good work !
@@hauiproductions8710 Glad that one worked. Let me know when you are able to get your hands on the board in Germany.
Not for 700 quid!!!
Pricey for sure, but I've been all in since the Dev Kit!
@@retroCombs I will clearly end up buying one of these, spending all this time just re-watching these two videos! The level of "cool" this thing eminates is unreal. The inclusion of BASIC and PETSCII keyboard, my oh my I need a glass of cold water over the head 🥛😎
@@DailyCorvid If you do, you must let me know how it's going. There's currently work on an add on board that will add a joystick port. Something I want to attack soon.
@@retroCombs Hey, is there any chance you can support USB controllers? Just I have a dozen or so of them already (versions of all the classics!),
I've not been able to get one working yet but there may be some updates coming that fix this. Not timeline though. Of course, I haven't tried this in awhile either. Might need to give it another shot.
200 is still to much for a System that have Like 0 Software, 0 Brands, only some dreamers behind. So you will only use the C64 Mode at end. 10 Mins 65 fun then only C64 what every calculater can Emulator today.
Check out files.mega65.org. There's a lot of fun software to explore with more on the way. For me, it's not about the package software but the upgraded BASIC 65. It's a blast exploring this language again after 40 years. I get it. This project isn't for everyone but for hard-core Commodore fans, like me, there's a lot of fun to be had.