Tachyon Forth / Blog: Recent posts

Seems some people have had problems formatting 32GB or larger SD cards on Windows to FAT32. Sure, it will format to "FAT", but that is exFAT, a proprietary filesystem. But have no fear, download the latest TAQOZ binary in TAQOZ./binaries/_BOOT_P2.BIX or TAQOZBOOT.zip

Load it onto a working FAT32 SD card and boot up with the terminal set to 921600 8N1 and preferably ANSI/VT100 without any CRLF translations.
I use minicom on Linux but TeraTerm on Windows. Both of these are proper ANSI/VT100 terminal emulators.... read more

I have been using bit-bashed SPI bus for the SD card which works out to about 1/10 of the P2 clock or about 32MHz maximum for a 320MHz P2 clock. There is a way to do it with smartpins SPI mode but it is messy and awkward to use and I have avoided it. Now I have hit upon a way to use a smartpin to generate 32 clocks at 1/4 of the P2 clock and while that is happening to just have 2 instructions repeated to handle the data 32 bits at a time.

Now this can run with an 80MHz SPI bus speed and surprisingly the SD card which is specified at 50MHz maximum just works anyway. Nonetheless I have also discovered CMD6 in the SD specs to switch to high-speed mode which I now use. I've confirmed this with different Sandisk cards but I can achieve 60Mbps data speeds and block read speeds of 7.5MB/s. This is really really good especially considering that it is only using 1-bit SPI mode. ... [read more](/p/tachyon-forth/blog/2021/03/bit-smashing-the-50mhz-sd-barrier/)

For many years I have hosted code on my publicly shared Tachyon Dropbox folder, and even various Google documents.

Well, that was easy for me and all my PCs would synch automatically but it was only a repository, not a web presence but I was busy developing Tachyon, and hardware, and commerical products, so I left it at that for several years.

Recently I have been using Mecrisp Forth that is hosted on Sourceforge by Mattias Koch. I had a need for a tiny support mcu that happened to be an ARM M0 core with plenty of Flash and enough RAM to host an interactive Forth, so I thought I would use Forth for its firmware rather than struggling with assembly or C libraries. ... read more