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#cbm — Public Fediverse posts

Live and recent posts from across the Fediverse tagged #cbm, aggregated by home.social.

  1. Here is another project I've been working on: github.com/ytmytm/1551-RAMBOar

    It's a RAMBOard, but for 1551. As far as I know this is the first of its kind. Just like on 1541-II a small daughterboard that plugs into the ROM socket. It adds 8K of RAM ($8000-$9FFF) plus 8K of extra ROM space ($A000-$BFFF).

    There is a patched ROM which uses the extra RAM as a track cache: it reads the entire track in one disk revolution, then serves subsequent sector reads from memory. Same idea as the track caching ROMs I did for 1541 and 1571.

    The project also includes a tiny fastloader wedge (HypaRAM) that calls the code embedded in the patched ROM. The same fastloader is already supported by the latest version of Parobek ROM for C16/116/Plus4.

    The performance is on par with DolphinDOS - about 27x faster than a stock 1541, about 7x faster than a stock 1551.

    #commodore #commodore16 #plus4 #hardware #8bit #cbm

  2. Now I have finalized the TCBM2SD firmware. I managed to squeeze in read-only support for disk images (D64/D71/D81).

    This pretty much completes what I wanted to achieve. The next step could be a cycle-exact 1551 emulator (Pi1551 base on Pi1541, but that's a completely different project).

    The author of Directory Browser kindly shared the source code with me, so there is now a version that supports the native fastload protocol (23x, ~9KB/s) for files and directory listings. The browser can be easily loaded using the SHIFT+RUN/STOP combination.

    Everything about the project is open-source and published at github.com/ytmytm/plus4-tcbm2s

    But if you own a Commodore C16/C116/Plus4 and you'd like to buy a ready-made TCBM2SD from me, please send me a message. Let me know how many you'd like and include your country of residence. I'll be ordering PCBs soon, so I’d like to estimate how many will be needed. Once I have that information, I’ll get back to you with a price offer.

    #1551 #tcbm #sd2iec #commodore #plus4 #cbm

  3. I made tcbm2sd!

    It's like Tapecart or SD2IEC but instead of IEC bus it uses native TCBM connection to C16/116/Plus4, simulating 1551 drive.

    github.com/ytmytm/plus4-tcbm2s

    Normal people would try to find a sd2iec and JiffyDOS for Plus4. I had no patience for that, so I spent last month developing this project.

    It's my first project with CPLD and it worked on the first try.

    The first revision uses Arduino Mini Pro with ATmega with 32K flash. It's not enough for full sd2iec port to service disk images, but works very well for file-based programs.

    It's fast! The embedded file browser (available always when you load '*' file) has a special fastloader feature, over 23 times faster than stock 1541, on par with DolphinDOS.

    See for yourself: youtube.com/watch?v=Cf42Z9H2Ji

    #1551 #tcbm #sd2iec #commodore #plus4 #cbm

  4. Attention #commodore #retrocomputing folks!

    I found a CBM-II keyboard and a CBM610 (w/o PCB) in my attic (yes, I should go up and dig more often, I suppose 😉 ).

    I wonder whether there's a turnkey solution out there to connect it to a PC (using USB). I am aware of Jens Schoenfeld's (iComp) "Keyrah v3". But have the strong feeling I am missing some essential point.

    #CBMpet #CBM
    #helpneeded #retrogaming

  5. In memory of Jack Tramiel who left us 11 years ago today 😢

    Born: December 13, 1928
    Died: April 8, 2012 (aged 83)

    #JackTramiel #Commodore #CBM #Atari #C64 #RetroComputing