Am Samstag, den 21.05.2011, 14:23 +0200 schrieb Miguel Angel Rodriguez Jodar:
> El 20/05/2011 19:37, Urs Koenig (QL) escribió: > > > @Miguel (Angel Rodriguez Jodar): Any news? > > Hi! I've made some improvements to the SPI code, so it works very reliable > for > all SD cards (not SD-HC) I've got at home. Currently I'm studing the inners > of > QDOS and learning how to write a directory device driver (I'm new to the > QDOS/SMSQ world). > > Using the Retro-X software ans dome custom C code, I've been able to make > longer > "QL movies". Some days ago I copied a whole Big Bang Theory episode into an > SD > card and replayed from my QL :) > > In the meantime, I've received a batch of more than 50 small flash EPROM > chips > (PLCC32). Half the size of a regular DIP EPROM, flash, not UV, and 128K size. > Being flash means that I can offer an option to let the user burn a new > firmware > version. As they are 128K insize (eight times the size I really need), I can > have a "fail safe" option, suitable for recover from broken firmware. > > My roadmap is: > - To have a design that let me operate a SD/MMC card from the ROM port (done!) > - To have a reliable and consistent set of low level routines for SPI > operations > (done!) > - Write a small device driver (not a directory device driver) to train > myself. > This device driver will use the SD card as a charactger device (in progress). > - Continue learning about QDOS/SMSQ and directory device drivers (I have the > source code of QUBIDE driver to assist me, and a book recomended by Rich > Melchor) > - Hopefully, have a firmware that let me use the SD card as drive MMC1, MMC2, > etc. > - Improve the design to acommodate a flash EPROM. Add the necesary logic into > the CPLD to let the user burn new firmware inside this flash. > - As this will mean I have to use a bigger CPLD (the current one is a > XC9572XL-PLCC44, with all pins used), I probably add logic into it to control > the SPI clock speed, so the initialization sequence will be consistent to the > SD > specification. I'm thinking of connecting the rest of the SD pins so it would > be > possible in a future to use the SD native mode transfer (4x faster) and > support > SD-HC cards. Currently, the speed obtained is fast enough to serve data to a > MC68008 at its maximum speed (is there anything faster than 128 instructions > move.l (a1),(a0)+ to copy 512 bytes from the SD card to memory? ) > - Betatesting phase. > - Available to the public Hi, this is actually a very interesting project. Expanding the QL with an SPI implementation could really open up a bunch of possible extensions , like communication to AVR microcontollers or even Ethernet. Some questions (I did read through the forum thread, but could not really find something: - How is the communication designed (especially, how did you implement write access) to the ROM port? - You seem to be planning to use a larger CPLD, could you add some select lines to implement more than one device on SPI? Cheers, Tobias _______________________________________________ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
