Macintosh IIcx Help Needed

[lazaj]

Hello,

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
  
• Mac FloppyEmu
  

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.

Thank you.

 

[keithiepoo]

Crap man, wish I could help. That is way beyond my expertise. Have you found a solution? 

I have a IIcx also, and would like to try to resurrect him as well. Unfortunately, I'm reluctant to "recap" or solder or anything like that. Plus, what kind of a monitor could I possibly get for it today?

 

[lazaj]

Solution found !

I've updated SCSI2SD V6 firmware to v.6.2.9 (08/12/2019), it was in version v.6.2.8. Now everything works like a charm !

To @keithiepoo :

Recap must be done if you want your IIcx to work again, old caps are killing your motherboard ...

Currently I'm using an old Samsung LCD SyncMaster 2131 monitor that natively support old Mac screen modes. I've also successfully tested OSSC open source scandoubler on a 4K PC monitor.

 

[beachycove]

One of the good things about a IIcx is that it will run some of the early A/UX versions, so it is a good machine for experimenting.

How is stability with Mode32 (which I take it you will have installed with System 7)? I have had some trouble with Mode32 recently, and would be interested to hear from others.