PC-3000 Forum

With regards to modifying headmaps on F3 drives, I was told by Ace tech support that I only need to modify level 2 on drives with two ROM levels.
Recently, I was told by a different Ace tech that I need to modify all the levels (some drives has 3 levels) to accomplish modifying the headmap.
Which one is it?

Hi,
Osity can you explain with pictures its not clear what you are saying

I think he's referring to how in ROM there are several different physical/logical head maps depending on the specific preamp used.

To answer your question, technically you'd only need to modify one of them, but that requires that you know which preamp is actually in use. If you don't know, then just modify all three to what you want and the mission is accomplished no matter which one is the activated head map in ROM.

Ace guys are just on another level of understanding, so they probably knew for that specific case which one needed to be modified.

Amarbir,
When you modify the logical/physical ROM on the menu on the right, in that same menu you will see an option with the number 1 in it.
If you click the number, it may change to 2 and sometimes 3, depending on the model.

Data Medics: Those numbers indicate which preamp you're working with?

Amarbir, here is the screen option I'm referring to.

I suspect that number there has to do with the fact that newer ROMs will actually have 2 (possibly 3) copies of the ROM code stored in the physical ROM package. I think you normally only need to modify the first copy though. The others are just a backup, but perhaps they give that option in case you want to modify things in the other copies for some reason (maybe if the first one is bad???).

I've honestly never seen a reason to bother with that feature.

Data medics, so you just change the logical heads with it set on 1 all the time and it works for you?

With Seagate, nothing "works all the time". These drives are as finicky as heck.

Mostly all I'm doing in ROM is modifiying the SAP control flags to start from only head 0 or 0 & 1. Or to adjust the logical head map in a case where I know which head is bad. That and to unlock the terminal locked drives. It's not often you need to do much more in ROM.

Based on my experience, ROM head map editing is not very efficient for families after Pharaoh or Grenada.

DataMedics wrote:Source of the post Mostly all I'm doing in ROM is modifiying the SAP control flags to start from only head 0 or 0 & 1.

I think it's the simplest and most efficient way for ROM modification on Seagate F3.

For some drives, logical head maps for preamp versions can be different, so we advise to change all of them, to be sure that the drive will start with a head map we set.