MaxTransfer , how and where.

[Trev]

And based on past observations, I'm under the impression this is a signed value, so 0x7fffffff would be the max, anyway. Anyone know for sure? Dependent on the device driver's interpretation of the data?

[Zac67]

And based on past observations, I'm under the impression this is a signed value, so 0x7fffffff would be the max, anyway.

LOL - just show me an Amiga with a RAM amount just remotely close to that value and I'll gladly explain everything to you...  :crazy:  ;-)

[Matt_H]

@ leytond

That setup is probably fine. You can verify it with Check4GB.

Are you still having problems unpacking the archive? Maybe your version of LhA is too old.

[Trev]

@Zac67

:-P My point, of course, was that 0x80000000 = -1 and any device that can transfer negative blocks of data certainly deserves our attention. ;-)

WinUAE supports up to 1.5GB, so it's almost there. I forget why Toni stopped there, but I think he's explained over on EAB. So, an OS3 device driver could, in theory, use a MaxTransfer value approaching 2^31-1 if Toni bumped up the Z3 memory emulation. :-)

And there's OS4 and MorphOS to consider. Did device driver tooltypes carry over to those with the same semantics?

[Zac67]

:-P My point, of course, was that 0x80000000 = -1 [...]

Obviously you mean 0xFFFFFFFF = -1, 0x80000000 = -2^31

AFAIK there are numerous issues with invalid signed long usage in AmigaOS, so anything beyond 2 GB is out of the question. Actually I was trying to refer to a real Amiga that even with several DKB3128s (or extremely rare) upgraded Fastlanes is far below that mark. :-)

[Trev]

Uh, d'oh! Yes. :-) The point of my point ;-) was the sign bit, so I could fib and say I meant -1 * n or something like that. Pardon me while I bludgeon myself with a two's complement primer.

[rockape]

Hi,

see http://wonkity.com/~wblock/a1200/a1200.html

"Q. I have have no idea what the MaxTransfer value should be for my drive. What value should I use?

 A. For unknown drives, the maximum "safe" value is 0x0001FE00. Other (older) drives may require 0x0000FFFF or even 0x0000FE00. The sure test is to copy files larger than the MaxTransfer value to and from the drive, checking for corruption afterwards. Pictures work well for this, as corruption is easy to detect."

Regards, Michael

aka rockape