https://github.com/go4retro/FlashPak

512kB FLASH ROM Cartridge for the TANDY Color Computer and Dragon Data Dragon System
https://github.com/go4retro/FlashPak

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512kB FLASH ROM Cartridge for the TANDY Color Computer and Dragon Data Dragon System

• Host: GitHub
• URL: https://github.com/go4retro/FlashPak
• Owner: go4retro
• Created: 2020-03-05T04:47:35.000Z (almost 5 years ago)
• Default Branch: master
• Last Pushed: 2024-05-07T04:43:26.000Z (8 months ago)
• Last Synced: 2024-05-07T05:32:33.835Z (8 months ago)
• Language: Assembly
• Size: 9.63 MB
• Stars: 8
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE_CC_BY_SA_4.0.txt

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• awesome-coco - FlashPak - 512kB FLASH ROM Cartridge Unit (Maker Community / Hardware Designs)

README

        
# FlashPak - 512kB FLASH ROM Cartridge Unit for the TANDY Color Computer 1, 2, 3, and Dragon

![](media/Unit.JPG)

This cartridge supports 512kB of system programmable FLASH ROM utilizing the RoboCop (Zumwalt) banking system.

## Technical Details

Banks are 16kB in size (technically, 16KiB - 256 bytes, since $ff00-$ffff is reserved for IO and vectors), which allows operation on all TANDY Color Computer models and the Dragon Data Dragon machines.  FLASH ROM appears at location $c000 in the memory map, while the banking register appears at $ff40.  The bits in the banking register are as follows:

| IO Location | Bit Location | Description                 |

| ----------- | ------------ | --------------------------- |

| $ff40       | 4:0          | FLASH address lines A18-A14 |

|             | 7            | 1 = Programming Enabled     |

The system is designed to utilize AM29F040B FLASH ROMs, but can also accommodate 16kB-512kB FLASH ROMs or EPROMs via J1-J5.  Please see schematic for more details.  If EPROMs are utilized, IC3 is not required (EPROMs cannot be system programmable)

To program please consult the AM29F040B datasheet for details, but essentially:

* set bit 7 to 1 and select bank in bank register

* via machine language, store the following values:

* store $aa in $c555

* store $55 in $c2aa

* store $a0 in $c555

* store desired value in $c000-$feff address ($fdff on Color Computer 3, I believe)

Sample stub code is available in the src/ directory.  The programming must be precise and cannot easily be performed from BASIC[1].

[1]: To simplify construction and reduce cost, programming is enabled for all of $c000-$ffff.  This includes the entire $ffxx IO region.  Unless care is taken to disable BASIC or the IRQ handlers from accessing $ffxx regions while sending the special programming sequence, the sequence will be disrupted and programming will not occur.

## Photos







## License

Copyright (C) 2021  RETRO Innovations

These files are free designs; you can redistribute them and/or modify

them under the terms of the Creative Commons Attribution-ShareAlike 

4.0 International License.

You should have received a copy of the license along with this

work. If not, see .

These files are distributed in the hope that they will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

license for more details.