Apr 27,2020
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  • Hi C64iSTANBUL, Here is a challenge for you.... I was thinking about your project and I did some digging in my parts bin. I found an old Vic 20 NTSC main-board. The Character ROM UD7 socket is very tight. It will not fit a regular 27C512 EPROM socket because of the total length of regular versions ROM replacement adapter. There is about a 5mm gap between the 24 pin socket and the VIC chip RF shielding. How hard would it be to say shift the EPROM back so that it is the same as the original 8-kilobyte 2364 ROM chip socket? The adapter has exactly the same wiring as the C64 EPROM replacement board. It is just a question of creating enough space.

    (DIY) C64iSTANBUL 2020-06-20 20:06:41Reply

    Hello Mr Eddie Bannister, I sent you an e-mail. Thank you.

    Mr Eddie Bannister 2020-06-21 11:20:04Reply

    Thank you very much C64iSTANBUL. I will report back as soon as I have build it.-

    Tuomas Kivistö 2021-01-14 13:47:36Reply

    Hi Guys! I would be interested in a vic-20 char rom adapter too. They seem to be very hard to find

    Mr Eddie Bannister 2021-01-29 03:43:02Reply

    Hi Tuomas, C64Instanbul has actually made one. I requires a very small wiring modification to make to compliant with the way the VIC 20 addresses chips compared to the C64. I made one my self and had it running in a Vic 20 for over 3 hours no problems. It suits all Vic 20 mainboard variants. An extremely well layed out design. Of course it will fit the C64 as well. Here's the link https://www.pcbway.com/project/shareproject/CHARACTER_GEN__ROM_REPLACEMENT_ADAPTER_FOR_COMMODORE_VIC_20_and_C64.html You will need a very small wiring mod. Which if done carefully won't be noticeable. Here is a video of it working with the mod... https://youtu.be/f_DzuPC9OdU I will post something on my modification. I am hopeful that C64istanbul can incorporate the changes into his great PCB design. I'll get back to you....

    Reply
  • Another sensible project, nice.. I think you can use this as a replacement for the Basic and Character ROM too. I have seen these jumpers used on a PCB. They have a nice action and the added benefit that the jumper never gets lost . https://www.acalbfi.com/be/Switches/DIP--DIL--SIP--SIL-/p/2-way-Jumper-Switch--Slide--2-54mm-pitch/0000000E3B another example https://www.pinterest.co.uk/pin/294774738089272822/

    (DIY) C64iSTANBUL 2020-05-20 22:14:02Reply

    Thank you very much Mr Eddie Bannister, I am very happy about your interest. This can be used for basic rom, but character rom is 4KB. Later I will draw a PCB for it, for multi language users. You can look at the image below. I like attractive colored jumpers, I agree you, you are right about them :) Thank you. https://www.commodore.gen.tr/forum/index.php?action=dlattach;topic=17182.0;attach=31270;image

    Mr Eddie Bannister 2020-05-29 07:06:51Reply

    I think your project is fine the way it is... Here's what to do regarding the CHAR ROM image...... Download a free windows program called HJ Split (you can do it from the windows command line- it's built in) to concatenate 2 x 4kb CHAR ROM files together. Now you have a an 8KB ROM image you can use in the E/PROM without messing up the ROM table jumper locations... This has been tried and I can confirm it works 100%.... https://hjsplit.en.softonic.com/ds ... Alternatively ... http://tech.guitarsite.de/eprom_image_multi_bin.html ........If you incorporate this project to C64iSTANBUL's COMMODORE 64 - KERNAL TABLE (901227 KERNAL ROM REPLACEMENT ADAPTER)...... https://github.com/svenpetersen1965/C64-Keyboard-Controlled-Kernal-Switch .........You have a non invasive way of changing the Kernal from the C64's key board....

    (DIY) C64iSTANBUL 2020-05-30 09:20:22Reply

    Thank you Mr Eddie Bannister. You are right about CHAR-ROM image, But while moding C64 to multi language we need to change both kernal and character rom. Kernal table and character rom table need to be placed side by site. this kernal table will not fit double of it side by side, Pins on the PCB should to be drawn "some kind of mirored". . I know Sven Peterson, he is a good man, his project is better than mine, but I want to keep it simple whitout any SMD components. Thank you very much. :)

    Mr Eddie Bannister 2020-05-30 10:46:27Reply

    Interesting. If you maybe say place an empty socket under one of the ROMS would that give enough lift to clear the 2 adapter boards placed side by side?

    (DIY) C64iSTANBUL 2020-05-30 20:05:37Reply

    You are right, It may be a good solution worth trying. Thank you.

    Reply
  • Thank you for your participation in our 3rd PCB Design Contest. 7 Tips On How To Make Your PCB Entries Stand Out 1.Choose the appropriate color of soldermask and silkscreen for your PCB project. 2.In addition to the PCB images generated by our website, you can upload more photos of the project. 3.The more detailed project’s description is, the better judges and other makers understand it. FYI, it is a good idea to insert a video, currently our platform supports “YouTube” and “Vimeo”. 4.Open for Gerber download and BOM download. 5.Frequently share your entries to your social media and some open source forums, allowing more people to vote your entry, like it, download the Gerber file and also place orders for your work. 6.After uploading your entry, please constantly pay attention to its page. There will be other makers asking questions about your PCB project, and timely responses and multiple interactions will be additional points. 7.Earn PCBWay Beans for participating in this contest: *Submit a project entry: 100 Beans *A complete introduction(Including BOM, project guide, code files, production and marketing plans): 200 - 500 Beans *With video introduction: 1,000 Beans

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