SGI o2 - Fast20 not working

[mzryz]

I understand that under: https://github.com/BlueSCSI/BlueSCSI-v2/wiki/Ultra-SCSI-Fast20-OverClock it was reported by another user that Fast20 was working for SGI o2. I am using the same SCSI port & cable that same user used (the CDROM cable)

Tested firmware's:
Beta firmware 2025-07-1, release 2025-08-02 and dev firmware 2025-08-28 without success.

Setting the following in bluescsi.ini causes failure:
[SCSI]
SpeedGrade="TurboMax"
MaxSyncSpeed=20

Setting the following in bluescsi.ini works normally:
[SCSI]
SpeedGrade="Default"
MaxSyncSpeed=10

Here is a photo of the o2 prom error:

Here is the system log:
o2-fast20.txt

[mzryz]

As a further set of investigations, I spoke to @jokker7718 who thinks his o2 was working on this branch: https://github.com/BlueSCSI/BlueSCSI-v2/tree/MergeTurbo20

I downloaded the repo and built it, flashed it to my pico2 and tested it out. First I tried in 10mb mode, which worked. I then swapped to 20mb mode in the config, which did not work.

I uploaded the log from the 2025-12-09-dev firmware just in case there were any differences.

20251209devfast20.txt

[CillyCil]

I run an SGI O2 with BlueSCSI and works for me. I had some issues when I named the images HD0 and HD1 but when I changed it to HD1 and HD2 it was fine

[SCSI]
SpeedGrade="TurboMax"
MaxSyncSpeed=20
System="Generic"

[mzryz]

@CillyCil please report your firmware version, thanks. Also is this internal on the cdrom cable, or external. What termination setting are you using. cheers.

[CillyCil]

v2025.08.02

TRM On

CDROM Cable

[thejpster]

I had some issues when I named the images HD0

The SGI SCSI controller is on ID 0 (and not ID 7).

I have an SGI O2 with a DB25 BlueSCSI on an 68-pin to 25-pin cable, and I was seeing data corruption when running the latest firmware. I also had an error on startup that said there was an issue with parity?

I'm reverting back to v2024.12.08, which is a version I knew to work on my old SGI POWER Indigo 2 (where later versions did not).

The config file is just a very basic one, setting System=Generic. The SD Card is a 64 GB model formatted as ExFAT.

[thejpster]

I resolved my issues by lowering the clock speed of my Pico W with SpeedGrade=B