Hello all,
This is a summary and a windup of the topic. Thank you for your assistance and patience.
The final ultimate solution , for me, was to put Debian 11 on the shelf, and to install MX-21.2.1-ahs-x86_64.iso. So MX is to become my new ‘base’ distro to control grub , run printers, do my email, etc.
I did the MX install in EFI mode and installed MX and grub onto disk hd1. It boots OK and gives an MX controlled GRUB Menu, with MX,Void, Debian and Devuan all detected.
On disk hd0 at present I have a legacy boot controlled by Void. I shall attempt to convert that to an EFI boot. It is good insurance having grub on 2 disks.
MX-21.2.1-ahs-x86_64 definitely operates my graphics card with the amdgpu driver
amdgpu 8167424 9
gpu_sched 53248 1 amdgpu
i2c_algo_bit 16384 1 amdgpu
drm_dp_helper 159744 1 amdgpu
drm_ttm_helper 16384 1 amdgpu
ttm 86016 2 amdgpu,drm_ttm_helper
drm_kms_helper 196608 4 drm_dp_helper,amdgpu
drm 622592 11 gpu_sched,drm_dp_helper,drm_kms_helper,amdgpu,drm_ttm_helper,ttm
nevj@trinity:~/Desktop
$ lshw -c video
WARNING: you should run this program as super-user.
*-display
description: VGA compatible controller
product: Navi 24 [Radeon RX 6400 / 6500 XT]
vendor: Advanced Micro Devices, Inc. [AMD/ATI]
physical id: 0
bus info: pci@0000:03:00.0
version: c7
width: 64 bits
clock: 33MHz
capabilities: vga_controller bus_master cap_list rom
configuration: driver=amdgpu latency=0
resources: irq:53 memory:c0000000-cfffffff memory:d0000000-d01fffff ioport:e000(size=256) memory:fb600000-fb6fffff memory:c0000-dffff
WARNING: output may be incomplete or inaccurate, you should run this program as super-user.
nevj@trinity:~/Desktop
and it does not hang during booting, like Debian11 did.
So, problem solved. time for a backup.
This topic is now closed. Thanks to all.
Neville