Thank you for a sane and sensible reply. It's a bit awkward to pull the tower from under the desk so I ran showconfig
Code:
SYSTEM: PowerMac3,5
REGISTERED: Unregistered
PROCESSOR: 7445/7455 (G4) (V2.1) 1000MHz (FSB 133MHz)
PROCESSOR: 7445/7455 (G4) (V2.1) 1000MHz (FSB 133MHz)
VERSION: MorphOS version 3.11, Ambient version 1.44, Kickstart version 51.40
RAM: Node type $8A, Attributes $1505 (FAST), at $14000CA8-$5133D000 (~979.2 meg)
BOARDS:
Vendor $106B Device $002D Apple Inc., UniNorth 1.5 AGP
Vendor $1002 Device $4966 Advanced Micro Devices, Inc. [AMD/ATI], RV250 [Radeon 9000 Series]
Vendor $1095 Device $3112 Silicon Image, Inc., SiI 3112 [SATALink/SATARaid] Serial ATA Controller
Vendor $1045 Device $C861 OPTi Inc., 82C861 OHCI USB Host
Vendor $106B Device $0019 Apple Inc., KeyLargo USB
Vendor $106B Device $0019 Apple Inc., KeyLargo USB
Vendor $11C1 Device $5811 LSI Corporation, FW322/323 [TrueFire] 1394a Controller
Vendor $106B Device $0021 Apple Inc., UniNorth GMAC (Sun GEM)
So what we've got is an ATI Radion 9000 (mac version). There's two other cards, a Sonnet SATA controller and a USB card, both working out of the box.
I just noticed that the system is silent on boot. It only starts making the awful noise after the first time something plays sound, thereafter getting worse with any activity - dragging windows, typing, network etc
[ Edited by khorse 24.02.2019 - 01:39 ] 
