User avatar
Shagittarius

Posted Sat Mar 20, 2021 12:08 am

So this has been driving me crazy.

It seems like the A2091 slows down my A2000 or has a memory conflict or something I'm not sure what but let me give you the symptoms I'm seeing and maybe someone can tell me what causes this:

My current system:
A2000
68010 & 2630 @ Stock w/2MB ram
A2091 w 2MB ram 7.0 roms 4GB HDD
Microbotics 8Up! Ram board fully populated currently set to 4MB
Indivision Mk2
SCSI2HD Drive with 4 Drives HD0 256MB/256MB/3.5MB, HD1 4GB, HD2 4GB, HD3 4GB
1 MB Agnus
3.1 ROMS / 3.1 OS

So there are lots of issues where I see slowdown on the system but I'm going to stick to 1 game that's easy to test and describe all the scenarios I've tested.

The game used for testing is Apidya (running in WHDLoad 18.whatever, latest version). What occurs happens in 2 places. First when the main logo for the game appears the music slows down. The second thing is the top 1/3rd of the game screen during gameplay doesn't show sprites. These are the two symptoms I'm watching for in this test.

No matter what config I try as long as the A2091 is installed and the OS booted from the HD I get these issues. If I leave the same configuration installed and boot from floppy (yes I know there is no WHDLoad in this case) the game runs fine. However, If I use a GVP-HCII instead of the A2091 then these issues don't appear. I've tried running this configuration in all ways imaginable removing extra ram, removing the a2630, changing the ram on the A2091 to 0. Nothing I do changes this issue as long as I'm booted to the HD using the A2091.

So I have two theories and maybe someone has some experience and can help me out. Is this just an issue with the A2091 using system resources and slowing this down, it doesn't appear to be a problem with WHDLoad because using the other SCSI controller I dont get this issue. It also doesn't seem like a ram conflict as when the only ram in the system is the A2091 the problem still occurs.

Or is this possibly a problem with the 7.0 ROMs on the A2091, I've heard stories that these were buggy and the 6.6 version is better, I recently picked up the 6.6 roms but unfortunately it sees all my 4GB partitions as nondos and I don't want to start over with my drives to test a different rom version which might amount to nothing.

Is it possible its a conflict with the SCSI2SD drive, or the large drives or the number of drives? Besides slowing the system down it all seems to run fine when its booted.

I'll answer any other questions , and thanks for taking the time to read this.

User avatar
McTrinsic

Posted Sat Mar 20, 2021 3:02 am

I don’t own any of this hardware. Except an SCSI2SD. 😉

However, it appears to me like EVERYone who ever has owned an A2091 has upgraded to the latest GURU-ROMs. Maybe that’s a start.

User avatar
Bulletdust

Posted Sat Mar 20, 2021 4:26 am

I'd really need to see a block diagram outlining how DMA works on the A2091, but it sounds to me like the A2091 steals cycles to chipram, halting either the processor or custom chipset to do it's thing as both the processor and custom chipset can access chipram.

Or...It's DMA could steal cycles between the CPU and your Microbiotics ram board?

User avatar
Shagittarius

Posted Sat Mar 20, 2021 10:53 am

Bulletdust wrote:
Sat Mar 20, 2021 4:26 am

Or...It's DMA could steal cycles between the CPU and your Microbiotics ram board?
This occurs without the Microbotics 8up! installed. The only mem in the system would be the 2MB on the A2091, the 2MB on the 2630, and the 1MB Chip ram.

User avatar
Shagittarius

Posted Sat Mar 20, 2021 11:00 am

McTrinsic wrote:
Sat Mar 20, 2021 3:02 am
I don’t own any of this hardware. Except an SCSI2SD. 😉

However, it appears to me like EVERYone who ever has owned an A2091 has upgraded to the latest GURU-ROMs. Maybe that’s a start.
Thanks, I've just ordered some roms and will try the latest guru roms when they arrive. Other than the specified RDB/Mountlist params I hope I won't have to reformat all my drives to get them to work with these.

User avatar
Bulletdust

Posted Sat Mar 20, 2021 3:02 pm

Shagittarius wrote:
Sat Mar 20, 2021 10:53 am
Bulletdust wrote:
Sat Mar 20, 2021 4:26 am

Or...It's DMA could steal cycles between the CPU and your Microbiotics ram board?
This occurs without the Microbotics 8up! installed. The only mem in the system would be the 2MB on the A2091, the 2MB on the 2630, and the 1MB Chip ram.
Hmmm, it appears the A2091 doesn't even support DMA, meaning that without that onboard RAM it's totally dependent on the CPU for data transfer. Interestingly enough, the GVP-HCII does support DMA transfers, making it the superior board.

Slowdowns exactly like those you describe on 16 bit OCS/ECS Amiga's using WHDload aren't uncommon where software is coded to make use of chipram as opposed to fastram due to bandwidth issues on the 16 bit bus - However that's usually only an issue using 68030 and faster processors, and isn't affected by the storage device.

Very odd.

EDIT: Just downloaded the 'Audios' version from here and ran it on my A1200 using WHDLoad, it runs perfectly - It's actually a really good game!

Have you tried both of these versions?

https://www.whdownload.com/games.php?na ... ton=Search

A1200 specs:

- ACA 1232 accelerator with 68030 @ 40Mz, 128MB of fastram.
- 2MB Chipram
- internal IDE to CF adapter as HDD.
- Indivision AGA MK2Cr.
- AmigaOS 3.1
- 3.1 ROM.
- Latest version of WHDLoad (whatever that is).

User avatar
Shagittarius

Posted Sat Mar 20, 2021 11:03 pm

Both versions act the same way. It doesn't matter weather I boot with the 68030 or 68010 , I still get the slowdown both ways running either in WHDLoad. No Slowdown of course running the floppy version and no slow down if I use the GVP-HCII and run the WHDLoad version...I've ordered the roms as suggested and I'll burn them and give em a try...other than that I'm still at a loss, hoping someone out there might have some info.

I also have an A1200 with an 030 and an 060 board and both run the game fine. It seems something in particular to the A2091 or at least an A2091 with 7.0 roms and ver. 08 SCSI controller. It even has the same problem with NoFastMem.

User avatar
Bulletdust

Posted Sun Mar 21, 2021 1:40 am

If I run WHDLoad on my A500 using the exact same 030 accelerator as fitted to my A1200 via an ACA500 using the ACA500 as the HDD, I get slowdowns on certain titles under WHDLoad. Run the exact same titles under WHDLoad on the A1200 using the exact same accelerator and even the exact same CF card/OS install and everything flies.

It was always titles that accessed chipram when they should have been using fastram. I wonder if it's got something to do with the A2091's onboard memory? Can you run with the A2091 fitted but with no HDD and connect the HDD to the GVP-HCII?

User avatar
Shagittarius

Posted Mon Mar 22, 2021 5:48 pm

The GVP-HCII is not recognized when the A2091 is installed but I think that might have more to do with the RAM onboard. The HCII also isn't recognized when I have my 8Up! Microbotics ram board in the machine either. I haven't tried the A2091 infront of the HD controller but i did try that with the 8Up! board and it didn't boot that way either.

Amazon sent me 2 tubes for holding the roms i ordered but only 1 rom chip so im still waitin g to get the roms to try the unofficial roms in my A2091.

User avatar
Shagittarius

Posted Mon Apr 05, 2021 9:59 pm

I just wanted to follow up a little on this since I've learned a bit more.

The guruRom is out because I can't find a place to source the adapter needed to install it.

As for the 2091 issues, when the 2091 is run in PIO mode the problems I noted are no longer present.

So If I run without my Z3 Bigram 2630, the A2091 runs in DMA mode and causes problems.

If I run with the Bigram installed the A2091 falls back into PIO mode and none of the problems are present.

As I understand it the GuruRom would be a solution as it should return most of the performance lost when running in PIO mode. I'm actually ok with the 100,000 bytes per second in PIO mode anyways...but if I can ever source a GuruRom adapter I will give that a try as well.





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