Yosemite on Optiplex 755

[donsjgm]

Hey people , Yes I did it. As soon as I learned where to post it, I'll share the particulars with you all.

 

[acebrain01]

Waiting for the guide!!!

 

[donsjgm]

Acebrain01 and all you guys, I'm almost afraid to reply here. I've been chastised for putting things in the wrong place on this site. I am not intentionally trying to break the rules. Still NO GUIDE YET. I submit my progress for you guys' help. I did upgrade my bios to A22 but was able to get up on A21. ACHI on the 755 panics the kernel and you have to use the LEGACY (ACHI) setting. I have tried unsucessfully to get the UniBeast installer to 'see' the internal HD. I am able to see an external HD on the USB buss and to do a complete install there. Now it's up and running. Been working hard to get it to the internal drive in a way that will boot from there. Anybody who can help, PLEASE do!!!! I'm still stumped.

 

[donsjgm]

We'll guys, I've spent the last two days trying to figure out Yosemite on my 755 since it crashed with a bad HDD. I Finally gave up and re-installed Mountain Lion. I think the hardware might not be up to the task. My system is FULLY functional even including iMessage so I'm going to leave it until I can get better hardware. I have another 755 and if I get bored I might work on it some more. Probably I'll see if I can sell it to move towards a newer machine. I didn't mean to give you false hope. If anyone does figure out the problem I would be interested.

 

[monkbait]

I was able to get Snow Leopard installed on my 755 with minimal issues. But, I'm getting kernel panics with the BIOS set to AHCI when trying to install Yosemite w/ Unibeast. I can get the Yosemite install to work if I set BIOS to Legacy, but then within the install process, the internal SATA hard drive is not visible.

I'm wondering if I can install it on a usb HD and then move that HD to the internal slot once it's finished?

I've tried every boot switch with AHCI enabled in the BIOS and always get the same kernel panic regardless. It does the same thing too whether or not I set the USB Legacy in Unibeast. Has anyone had luck doing this?

 

[donsjgm]

I haven't worked on the problem since Christmas. In answer to your question, yes it can be installed and ran on an external hard drive but I had no luck moving it to the internal drive. The problem with running it from the external drive is it corrupts itself when shutdown and requires a re-install every time. I spent several days trying to figure out an answer and set the project aside (disgusted) for a while. I had MUCH better luck with the A21 BIOS than the A22. I've undertaken some C programming with the intent of trying some system modification to see if I might resolve this but became sidetracked with the offer to sell a program thru a national distribution. I've been racing to make their spring catalog but intend to return to working on solving this as soon as the project is complete (really soon). In the mean time I had been hoping that someone would 'find the answer.'
"Legacy" is USB setting and still is AHCI. Use Legacy setting in the BIOS. To boot the installer use -v Graphics Enabler=YES. Nothing I did could "see" the internal drive but a USB drive is recognized by the installer. I used an external dock with a hard drive. After installing on the external drive I again tried to place it in the machine but still the drive isn't seen. It is visable on the USB buss. When booting from the installer & external drive I again used -v but Graphics Enabler=NO was necessary. From there GOOD LUCK.

 

[monkbait]

Thanks for the reply and great info! So, I do have A22 BIOS on it. Wondering if it's possible to downgrade it to A21? I got the box with A02 on it and could not install Snow Leopard until I updated it to A22. Now I wish I would have read this post before starting.

OK, just tried and answered my own question, I reverted to A21 and trying it again. It failed to update BIOS on the frist try, just had to do it a second time and it took.

 

[donsjgm]

A02 is REALLY hard to get OS X to run on. Until replying to your post I hadn't put anything out about A21 vs A22. I too am going to convert back to A21 just for the purpose of working on Yosemite. When I upgraded to A22, I seem to remember that reverting to A21 was an option. I am able to get 10.8.5 Mountain Lion to run VERY reliably and am using that until I come up with a solution. Mavericks was horrible and I gave up on it after only 1 try. Yosemite is much better written and I am hoping to use it (someday). After just 1 day after install of Mt. Lion, Apple dropped me from the "whitelist" and iMessage quit working but all else is good with 10.8.5 using A22.

 

[monkbait]

OK, back on A21 but same thing, no SATA in the install visible and only gets into install with Legacy set in BIOS.

 

[donsjgm]

Just got back from Dell site. Went looking to tell you how to get back to A21. With A21 I WAS NOT able to see the internal drive either. Legacy setting is only legacy USB. The BIOS is still ACHI. With Legacy USB the installer CAN see an external hard drive. I was able to install and run it from the external HD just never solved the problem of getting it to an internal drive. You are now up to date as far as I had been able to go.