Re: Superdrive 2000?

On 6/5/2018 6:01 PM, smf wrote:
>
>>> I can't see where this is correct.  If this were true, there would 
>>> have been no
>>> reason to have a switched JD.  In reality, the games and such were 
>>> so dependent
>>> on the specific sequence of code fragments in the CBM ROMs, even 
>>> patched JD
>>> failed in some cases and required one to swap back to std ROMs.
>
> Being able to shut JiffyDOS off completely is different to CMD 
> producing hardware that swaps between 1541 ROMS and an actual ROM 
> overlay at run time.
>
> Anything incompatible with JiffyDOS would need it to be disabled 
> either way, swapping between the 1541 ROM and an overlay would operate 
> exactly the same because the same values would be presented to the 
> CPU. There just wouldn't be the need of copying any of CBM code.
I could be wrong, but I think you're saying that CMD could have produced 
a PCB that allowed one to place the 1541 ROM on the PCB and the JD ROM 
would be on the board, and the logic on the board would switch between 
the two ROMs at key times or for key accesses to effectively "patch" the 
CBM ROM with the JD routines as the addresses were accessed.

Sure, that is possible, but highly impractical.  While it may have 
worked on the 1541, if you remove the shield and pitched, it would not 
work on the 1541 with the shield in place, the 64 with the shield in 
place, the 1541-II at all, and I am pretty sure it would not work on the 
1571 or 1581.  There was simply not enough room for such a bulky item in 
those devices.  Your only option would be to put a 24 or 28 pin cable 
from the ROM socket to the board, placed outside the unit, or dispensed 
with shields (and even then, the 1541-II won't work due to the spacing 
from the top of the socket to the bottom of the mech.  Other units could 
also have the same issue.
>
>
>>> I find it more plausible that they entered into an agreement with 
>>> the FSD drive
>>> manufacturer in good faith, assuming that the manufacturer would 
>>> handle the rest
>>> of the legalities.
>
> If the drive manufacturers were able to sort out the legal issue of 
> shipping 1541 roms, they wouldn't have been buying JiffyDOS licenses 
> in the first place.
>
> The drive manufacturers must have thought that licensing JiffyDOS 
> solved their problem completely or they wouldn't have done it.
I actually agree with this.  But, FSD's naivete should not be held 
against CMD.  I continue to believe CMD acted in good faith, and the FSD 
firm either did not understand or chose not to understand their position.

Jim