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The Compact Computer 40 (CC40)


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Finish that migration yet? :)

 

Greg

Yep. My current challenge is finding a bootloader that works with SD cards and fits in 2048 bytes.

 

If folks are wanting to move now and can program an AVR atmega328, let me know, and I'll kit up the parts. Otherwise, I need to find a way to do field upgrades, or the shipping of boards back and forth will becoming tiring very quickly. I am sure folks will find bugs, so user upgrades are very important.

 

I have a 3092 byte SD card bootloader, but have not gotten it down to 2048 bytes yet.

 

Jim

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Yep. My current challenge is finding a bootloader that works with SD cards and fits in 2048 bytes.

 

If folks are wanting to move now and can program an AVR atmega328, let me know, and I'll kit up the parts. Otherwise, I need to find a way to do field upgrades, or the shipping of boards back and forth will becoming tiring very quickly. I am sure folks will find bugs, so user upgrades are very important.

 

I have a 3092 byte SD card bootloader, but have not gotten it down to 2048 bytes yet.

 

Jim

 

There are a handful of us with programmers that can do that and test for you. Just let us know. Are they going to be kits? If so, I might have mine sent to someone like Greg for assembly since my hands shake too much to solder right now.

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Yep. My current challenge is finding a bootloader that works with SD cards and fits in 2048 bytes.

 

If folks are wanting to move now and can program an AVR atmega328, let me know, and I'll kit up the parts. Otherwise, I need to find a way to do field upgrades, or the shipping of boards back and forth will becoming tiring very quickly. I am sure folks will find bugs, so user upgrades are very important.

 

I have a 3092 byte SD card bootloader, but have not gotten it down to 2048 bytes yet.

 

Jim

I can do that. Sorry for the sysadmin joke ;)

 

Greg

 

Sent from my LG-H872 using Tapatalk

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There are a handful of us with programmers that can do that and test for you. Just let us know. Are they going to be kits? If so, I might have mine sent to someone like Greg for assembly since my hands shake too much to solder right now.

Happy to build yours Jon

 

Sent from my LG-H872 using Tapatalk

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  • 1 month later...

Any updates on the SD card drive for the CC40?

Yep.

 

Not having a ton of time to work on bootloaders, so I am switching plans. I am recompiling the design for Arduino (I use an atmega328, so this is pretty easy), and I will sell (or folks can grab via eBay) an Arduino UNO + Data Logger card to test with. This way, they can dload new code with USB, and I can get feedback on the code (and an arduino is nice to have anyway). That will eliminate the need to solder (acadiel's concern) and I can get on with development without having to worry about packaging right now.

 

Thoughts appreciated.

 

Jim

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  • 1 month later...

Sorry about the delay. Work and Life happened, etc., blah, blah.

 

I have pushed the first pieces of Arduino support into the repo:

 

https://github.com/go4retro/HEXTIr/

 

I am still getting a return code of 01 on SD card mounting, so looking into that. Once I overcome that, I should be ready to test. For those with the Arduino Uno and a SD shield, feel free to pull down and get the dev environment up and running.

 

I am not using the Arduino dev environment, as moving the code over to arduino C++ was a large undertaking, and Arduino is not the final platform. But, I am hopeful folks can get a dev env going quickly. Feel free to ask questions.

 

Jim

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Arduino support is working. I had to move a few pins, as the real time clock on this shield uses a few of the pins.

 

Instructions are in https://github.com/go4retro/HEXTIr/tree/master/doc/arduino

 

The shield does not automatically connect Card Detect (CD), Write Protect (WP), and the LED (L1) to the Arduino pins, so one must do that.

 

To build, you'll need make, the avr-gcc tools, avrdude, awk, and I think that's it.

 

make CONFIG=config-arduino program fuses

 

Replace in config-arduino the AVRDUDE_PORT with your Arduino COM port. Mine is COM32.

 

Let me know if someone gets it running.

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  • 5 months later...

Way back on the 1st page of this thread I mentioned I had gotten a hold of a new-in-box CC-40, but was hoping for storage and memory expansion solutions. Looks like some headway had been made, but has now stalled. Just posting to see if there is still work being done on this front for it. Thanks to all who've worked on it so far!

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Well, the Arduino version works, and anyone can wire it up. Code is on the site. I am moving to a larger uC so I can get the bootloader to fit... Mainly, though, work has interfered, but I do quite a bit of my stuff during the Winter, so hopefully I cna put some more into this in the next month or so.

 

Jim

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Well, the Arduino version works, and anyone can wire it up. Code is on the site. I am moving to a larger uC so I can get the bootloader to fit... Mainly, though, work has interfered, but I do quite a bit of my stuff during the Winter, so hopefully I cna put some more into this in the next month or so.

 

Jim

Cool can't wait to see what you get done!

 

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  • 4 weeks later...

OK... Sorry for the long delay. As noted, I am moving to a larger uC, so I had to rework things a bit. The good news is that I have the basic load/save working again and am working to implement more of the protocol.

 

Still a ways off (I spent the last 2 weeks tracking down an interrupt issue), but I have not forgotten the project or the goal.

 

Keep bugging me. I am still trying to deliver.

 

Jim

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  • 8 months later...

My second attempt did great for updates, but is not handling the timing good enough.  So, I have two parts that I think can make a whole.  I am going to combine my two attempts into a single project that will heopfull have what everyone needs.  It'll most likely be around Christmas before I can show something off.

 

For now, I do have an arduino project online you can wire up to do rudimentary SD usage:

 

https://github.com/go4retro/HEXTir

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I have an idea as well; I don’t know how feasible it is.

 

The cpu for the CC-40 TMS70C20 has something like 2K of processor ROM in the top of the memory map where a lot of core system routines were held (Hexbus, file saving and loading, etc.)


The TI-74 used a TMC70C40, and had 4K of processor ROM, including the data routine that pulsed the MSB or LSB Hexbus line to save/load from cassette.

 

TI-74:

F000-FFFF - 70C46 ROM (4K)

 

CC-40:

F000-F7FF - Unused (2K)

F800-FFFF - 70C20 Processor ROM (2K)

 

I wonder if we can overlay the 4K of processor ROM from the CC-40+ that Ksarul has into a regular 40 and then put some resistor dividers or other cleanup circuitry and make a cassette cable for the 40?

 

 

 

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  • 3 weeks later...

Got an Arduino and Data Shield working. Was a learning curve, as I have never worked on microcontrollers before and some finagling is needed to get it to compile on a Mac. Make flunked out at setting fuses; seems that third party Arduino clones do not like having fuses changed. Nonetheless, what was compiled and uploaded did the trick. I have so far successfully tried SAVE, OLD, and LIST (to dump a Basic program to a text file).

 

Thank you Jim!

 

Attached some photos of my build. Since I do not have a HexBus type cable on hand, I stacked some headers soldered directly to the data shield and the board just plugs into the rear of the CC40.

 

Keith

 

IMG_4099.JPG

IMG_4100.JPG

IMG_4101.JPG

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