ZorRAM vs. Busters

[mboehmer_e3b]

Guys, any comment on Buster 7 compatibility?

Yes, only one: get a Buster 11 :-)

We haven't tested with Buster 7 - I think I have at least one crouching around in my spare part stuff, but Buster 7 is definitely outdated. My spare part is just for historical interests :-)

Michael

[mboehmer_e3b]

I don't know what the facts are, only my observations.

In my Buster9 A4000, zorram did not work.
In my Buster9 A3000 it worked fine...

So it's not strictly an incompatability with Buster9.

It's the combination of Bridgette and Buster 9. Buster 9 has "wrong timings" compared to Bridgette, while Buster 11 has the "correct" timings compared to Bridgette. I.e. control signals of Buster 9 are "too fast" compared to the data path through bridgette.

A3000 has no bridgette.

Michael

[mboehmer_e3b]

The Deneb worked fine on both machines, but I don't remember trying it with the zorram.

DENEB needs to take care of certain Buster "features" for DMA issues, timing is much more relaxed than in ZorRAM case. DENEB PIO must work in both Buster 9 and 11 setups (and is know to, except for certain issues being discussed on a1k.org, mainly related to 68ec030 issues, mainly concerned is the A3630).

Michael

[mboehmer_e3b]

I recall this causing compatibility issues and that Buster11 was the best chip (but not error free)...

Buster 11, DENEB and DMA will lead to lockups in hardware if ZorRAM is being used heavily.

This is a "feature" of Buster 11, a remnant of the famous Buster 9 lockup which was claimed to be removed while stepping to rev11. It is still there, harder to trigger, but it will hit you just as a matter of time and statistics.

But: I have written a new firmware for DENEB which can cope with that situation. The DENEB FPGA takes over some buster work, and allows (according to all our tests in lab and at customers) stable operation of DENEB DMA and Zorro III RAM.

Firmware is available on request for testing, and will be published as free upgrade for all DENEB customers as time permits (i.e. I need to find some time to recompile the FPGA sources in a cleaned up version :-) )

Michael

[mboehmer_e3b]

I installed it immediately and tested extensively for a few hours. Looks like I was worried needlessly, because it works great even with Buster 7 .

;-) Buster 7 lacks all DMA support, and therefore also almost all DMA related "features" found in Buster 9 and 11.

Michael

[mboehmer_e3b]

It seems to be, that ONLY buster 9 is able to handle TWO ZIII-cards in DMA-mode.
But it needs some workarounds to fix some timing problems, Deneb firmware can handle ist.
Buster11 is fixed in some issues but is only able to handle ONE ZIII-card in DMA-mode.

Buster 9 can handle two DMA controllers on Zorro III if both of them keep to some rules (i.e. Fastlane Z3 and DENEB as only working combination, no A4091, no A4kT onboard SCSI).

Buster 11 is more complicated. One DMA controller works fine as long as no Zorro III based RAM is available, with Zorro III RAM being present the new DENEB firmware is needed.
More DMA controllers should be possible, but this would need a small hack on DENEB, and even a more refined DENEB FPGA firmware.

Michael

[mboehmer_e3b]

Erm, the same? Cept DKB 3128 works in all Amiga's regardless of buster?

It works as long as you don't do DMA on Zorro III. Zorro III lockup will also occur with DKB3128 and Buster 11 if Zorro III DMA is being used.
Buster 11 doesn't care about the manufacturer of the Zorro memory board :-(

Michael