hi ...
3rd email in this saga, which asks the question:
Should the DIDS spec allow for vendor-defined pages?
In the proposed DIDS layout, page IDs above 32767 are reserved. The opens the door for vendor specified pages.
A maker may wish to define and add non-standard pages to their DIDS for (at least) one of the two following reasons:
* the page definition has been proposed to the standard, but is not yet part of the DIDS spec. this allows a maker/vendor to ship a device with that information without being held up by (or worse: *violating*) the specification.
* it may be device implementation specific data, and by allowing the additional pages to be included in the DIDS it allows using a single EEPROM chassis design
Benefits include:
* allowing re-use of pre-existing chassis PCB layouts without needing to adjust them so as to add additional EEPROMs
* prevents inappropriate use of mass storage (do we really want to see more “magic” partitioning, such as magic offset values, for mass storage devices?)
* conservation (the ecological argument): if there is space on one EEPROM, why use two?
With the proposed paged layout, there is zero technical reason why allowing make/vendor-defined pages would be a bad thing. The DIDS spec has 10s of 1000s of page IDs left to use for standard pages and it comfortably allows for vendor pages without making reading/writing of the DIDS any harder or more complex. There is zero cost to the EOMA68 standards or the DIDS layout by allowing maker/vendor-defined pages. Zero.
The only reason provided so far is a desire to control vendors. As a maker/vendor, I find that concept utterly repugnant when there are reliable and sensible technology answers.
Specifications should standardize and enable, rather than shackle, adopters.