First of all sorry for my really Bad English.
I'm an electronic and embedded software engineer and I have a lot of cool tools at work.
I've bought a Macintosh IIcx, I recapped it and fully cleaned the logic board in IPA bath, repaired a broken trace in startup circuit.
The Macintosh IIcx config is :
8x 1Mb RAM
120 Mb HDD (not Apple)
Nubus Apple "Toby" video card
On the HDD, system 7.5.3 is installed and seems to work well. I've launched some apps and games without any problem.
Now, I have replaced the 120 Mb HDD with an SCSI2SD V6 to reinstall a clean system on it.
Here problems starts, I can't install system other than system 6. With system 6 everything is working.
When I try to install system 7, 7.1, 7.5, etc... The installer crash with "address error" or "bus error" at step "building system".
I've tried to dd an image build from emulator, from http://www.savagetaylor.com/, etc.. it boots but fine but randomly bomb with "address error" or "bus error".
I've tried to swap the RAM, changed SCSI ribbon cable ...
So I really need help or advice.