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DragonMMC progres report.

Posted: Fri Apr 08, 2016 10:46 am
by prime
Hi all,

Just a little progress report for where I'm at with this project.

Hardware is pretty much stable now, I'll need to do another minor revision before going gold as it where but that's mainly to tidy things up so the final board doesn't have patch wires on it......

Software is now working fairly well, and can do the following :

On startup detects machine it's running on and uses the appropreate version of the firmware for that machine (Dragon or CoCo).
Has access to the FAT filesystem on the SD/MMC card through custom commands, can save & load directly to FAT.
Emulates tape loading to load / save .cas files from the SD/MMC, but obviously at much higher speed.
Can load cartridge images into the onboard RAM and optionally autostart them.
Has (optional**) emulation of Dragon DOS (1.3) and RSDOS, dependent on machine, and can have up to 4 disk images loaded at the same time.

** Dos emulation can be switched on and off with a configuration option, you simply set the option, and hard reboot the machine either by power cycling or setting $0071 to 0 and resetting.
This allows the loading of programs that will not work with dos enbabled.

The firmware is now completely field upgradeable, the onboard AVR microcontroller, can bootload it's own firmware and can also program the CPLD firmware when needed.
Since the Dragon / CoCo firmware is in an EEPROM this can also be updated via a program run from the SD/MMC card.

Comments ?
Anything people would like implemented?

Cheers.

Phill.

Re: DragonMMC progres report.

Posted: Fri Apr 08, 2016 11:05 am
by admin
I *think* this may be there already - but ability to automatically mount and run a specific CAS file - such as Autoboot.cas so we can autoload a menu system??

Re: DragonMMC progres report.

Posted: Fri Apr 08, 2016 12:03 pm
by prime
admin wrote:I *think* this may be there already - but ability to automatically mount and run a specific CAS file - such as Autoboot.cas so we can autoload a menu system??
Yep that's there, set by a config option, actually not a specific cas file but a basic program saved on the FAT with MSAVE.

Cheers.

Phill.

Re: DragonMMC progres report.

Posted: Fri Apr 08, 2016 12:26 pm
by pser1
Hi Phill,
glad to hear about your project again!
Talking about autorun CAS files, there are some that load a small amount of code (in the hooks area) that
autoruns and then it controls the needed data-code blocks to be loaded.
I assume that this will work too, unless they use internal non std ROM calls instead of the known and
recommended entries (bit-byte-block in-out ...)
I look forward to see how it evolves.
By the way, have you planned to make a small batch to sell?

cheers
pere

Re: DragonMMC progres report.

Posted: Fri Apr 08, 2016 1:18 pm
by prime
pser1 wrote:Hi Phill,
glad to hear about your project again!
Talking about autorun CAS files, there are some that load a small amount of code (in the hooks area) that
autoruns and then it controls the needed data-code blocks to be loaded.
I assume that this will work too, unless they use internal non std ROM calls instead of the known and
recommended entries (bit-byte-block in-out ...)
Most of them should work, I've tested a few, if you know of some you think I should test :)
I look forward to see how it evolves.
By the way, have you planned to make a small batch to sell?
Yep will be making some once it's been tested a little, Simon has one of the V1 boards, and Bas (on the FB Dragon group, not sure if he's on here), has the other V2 prototype.

Cheers.

Phill.

Re: DragonMMC progres report.

Posted: Fri Apr 08, 2016 1:38 pm
by pser1
I am really interested on this project, so put me down for one board.
If I could be of help, just let me know ... I will have a peek at some 'strange loading'
CAS files along this weekend.

cheers
pere

Re: DragonMMC progres report.

Posted: Fri Apr 08, 2016 4:08 pm
by tjewell
Hi Phill, I'd definitely love to try a board - as Tormod will testify, my collection of Dragons are a cantankerous bunch that seem to cause problems in even the best tested hardware! If you've got enough testers, put me down for the first production batch!

Cheers, Tony

Re: DragonMMC progres report.

Posted: Fri Apr 08, 2016 7:09 pm
by robcfg
Would it be a silly feature to load cas files at standard speed?

It would be nice to be able to show people the difference between standard and enhanced loading speeds.

By the way, Will it support VDK/DSK files?

Count me in for a board too! :mrgreen:

Re: DragonMMC progres report.

Posted: Sat Apr 09, 2016 6:48 pm
by Stig
This sounds so awesome ! I will definitely be having one of these when they are ready.

I am not sure if you have mentioned this in the past but does this work via the cartridge port on the dragon ?

If so, will it come with a custom plastic shell or will it fit inside a existing standard dragon cart shell ?

Thanks for the update Phil, really looking forward to this.

John

Re: DragonMMC progres report.

Posted: Mon Oct 31, 2016 3:21 pm
by bluearcus
Hi Phil,

Sounds good! Will the 32K of RAM function as a standard external high 32k bank using the SAM addressing mode change only? Or in plain speak, does this board make a Dragon 32 into a conventional Dragon32(64).

Cheers,

Mike