[Coco] Get those hard to find disks...
neilsmorr at gmail.com
Thu Dec 11 18:37:30 EST 2008
The Model 100 crowd have a new gadget called the NADSBox. You can plug any of several different memory cards in it like the SD card and you have a 2 Gb drive for example. Here is a description:
1. The processor has 64K of Flash Program memory that is self programmable.
2. I split the 64K into 3 sectors, one with the help of Microchip. They are a 2K Boot Sector (Microchip's contribution), a 30K Firmware Sector, and a 32K Application Sector (although now that I write this, maybe I will make the Firmware Sector 32K and the Application Sector 30K).
3. The Boot Sector is write/erase protected and contains firmware upgrade routines to rewrite the Firmware Sector from data stored in an external 128K byte serial EEPROM on the PCB. The code in the Boot Sector has been tested extensively as it is not field upgradeable.
4. A command in the Firmware Sector, the 'flash' command, reads the new firmware from a file on the memory card (with standard FAT format), checks the validity of the firmware, writes it to the appropriate location in the external 128K EEPROM, writes a command to the processor's internal data EEPROM to inform the Boot Sector that an upgrade is requested, and jumps to the Boot Sector to perform the upgrade.
5. The Boot Sector detects the "Update Requested" command, reads the new firmware from the external EEPROM and reprograms the Firmware Sector. After the Boot Sector has reprogrammed the Firmware Sector, it clears the "Update Requested" command in the internal data EEPROM and jumps to the pre-determined Main Entry location to start using the upgraded firmware.
6. The Boot Sector also has provisions for recovering a factory installed and locked "Firmware Recovery Image" from a special sector in the External EEPROM via a "Recovery Jumper" on the PCB. This is provided in case the flash update fails, thereby corrupting the firmware, and the unit can no longer read FAT format files to "retry" the upgrade. This operation requires no user intervention except to install the jumper and turn the unit on.
7. In the event of total catastrophic failure (both Flash upgrade fails AND the recovery image mysterously disappears), the Boot Sector can also receive a recovery image through the RS-232 port.
8. The Firmware Sector contains a command called the Application Manager (appmgr) that reads optional programs (xmodem, format, DriveWire, etc.) from the memory card, programs them into the Application Sector and "stitches" them into the operation of the NADSBox so they look like built-in commands. The appmgr is still work-in-progress and one of those features I mentioned that I have to avoid trying to work on prior to sending NADSBoxes out for testing and general use.
So to make a long story long...to upgrade the firmware, you simply download the upgrade image from my website, save it to an SD card and insert into the NADSBox, go to the command line prompt and type "flash filename". The firmware does the rest.
It'll handle up to 4 Gb cards as is BTW. That's over 20,000 floppies (I think). It connects via the serial port.
----- Original Message -----
From: "Michael Robinson" <deemcr at robinson-west.com>
> Generally I'm disinclined to buy floppy disks, but there
> are some programs, like Gauntlet II, that won't run over
> drivewire. Floppies are inherently unreliable.
> is interesting, but a little spendy unfortunately.
> Now then, my deluxe joystick could be replaced...
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