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TACHYON O/S V3.0 JUNO - Furiously Fast Forth, FAT32+LAN+VGA+RS485+OBEX ROMS+FP+LMM+++ - Page 109 — Parallax Forums

TACHYON O/S V3.0 JUNO - Furiously Fast Forth, FAT32+LAN+VGA+RS485+OBEX ROMS+FP+LMM+++



  • K6MLE wrote: »
    Has anyone written the code to support the RA8875 display board from Adafruit? I'm attempting to do this, but didn't want to reinvent the wheel. It will be my first 'driver' foray with Tachyon!

    There was something similar with a QVGA TFT driven from an SSD2119 via SPI. I must say that the "board" which is basically the chip is more expensive than a 5" TFT with the chip!

    Are you on this thread because you are still using V3? Bear in mind that V4.7 is the latest supported version and V4 has its own thread too.
  • Hi Peter,
    I'm using v4.5 on this particular project. How does it differ from 4.7?
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2018-02-02 08:22
    K6MLE wrote: »
    Hi Peter,
    I'm using v4.5 on this particular project. How does it differ from 4.7?

    4.7 packs more into the cog kernel by encoding common 2 to 1 operations such as AND OR etc as a wordcode with the 9-bit PASM instruction embedded. So some of the previously slower instructions now run straight from the cog and there are more of them since the only cost of having the more esoteric instructions was a header. The only sacrifice here was that the 2:1 ops ran a little slower but overall the system ran faster. There were some other instructions added as well as a single 32-bit SPI write etc and maybe add back in a fast SPI block read after I squeeze out a couple more longs.

    At the moment I am adding automatic 16-bit CRC handling to the HSUART ROM to support MODBUS and it may include more still. For a test I have five coms ports (besides the console) active and unlike the 4-port serial from the OBEX, these ones are specialized to easily handle 2M baud or more jitter-free as well as RS-485 or single wire autoduplex serial. The user parameter supplied to the HSUART ROM is also being simplified, just point to 3 longs in memory that specify pins as a &mode.te.txd.rxd style long, speed, 16-bits for rxbuf size, and 16-bits that point to the data structure (txbuf,stat,rd,wr,rxbuf). You can send commands to HSUART itself via a 16-bit command (vs 8/9-bit data).

    Since this thread is sooooooooooooooo long, I have a new thread for V4.

    EDIT: EXTEND for 4.7 allows includes extras plus the new style .AS" for printing formatted numbers and text.
  • livinlowe wrote: »
    Hi Shawn, I am assuming you are trying to download serially to the running kernel. Have you set your terminal to 15ms or more LINE delay (not character)?

    Otherwise a little more information will help, it doesn't cost anything and saves a lot of time.
    LOL, yeah more info would be good. I copied and pasted the source code into the propeller tool and was doing a compilation check when I got the errors. pwm32 is already defined. I have tried to copy and paste the whole google page versus just the source code section, but the prop tool found tons of errors when I did that.

    BTW, this is a pretty impressive thing you have created and you should feel proud of your hard work. I have downloaded tera term and set the line delay to 20, just cant get the program to compile so i can download it into the propeller.

    Looking forward to playing with tachyon( which I only barely understand because I used a HP48 in college so I understand the stack concept)

    Thank you for your time

    I also came to Tachyon by way of HP48 infatuation. Been at it by inches for several years now and Peter's work continues to impress. I add my thanks to yours.
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