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do anyone know which CPU Hitachi-HTS543225L9A300 uses?

August 7th, 2019, 2:12

do anyone know which CPU HTS543225L9A300/HTS545025B9A300 or any IBM/Hitachi(M24) uses?

I have the ability to RE FW code.
Once I know the cpu/instruction set of these drives, I will start my research, and post results here.
Many people will benifit from that.

Re: do anyone know which CPU Hitachi-HTS543225L9A300 uses?

August 7th, 2019, 10:26

It's modified Mitsubishi core, no available disassembler for it, no documents either

Re: do anyone know which CPU Hitachi-HTS543225L9A300 uses?

August 7th, 2019, 11:22

hello Doomer, thanks for this valuable info.
can you tell which Mitsubishi core is close to it, part no. etc.
and where you got this info from?

disassembler is not a problem, I can create one.

Re: do anyone know which CPU Hitachi-HTS543225L9A300 uses?

August 7th, 2019, 11:46

genius wrote:hello Doomer, thanks for this valuable info.
can you tell which Mitsubishi core is close to it, part no. etc.
and where you got this info from?

disassembler is not a problem, I can create one.

I don't know which one, I know it's a 24bit core with proprietary opcodes

Re: do anyone know which CPU Hitachi-HTS543225L9A300 uses?

August 7th, 2019, 12:04

Dear Doomer, thanks for your quick reply.
your info is vital and it will point me in right direction.
if you have more info, please keep me updated.

Re: do anyone know which CPU Hitachi-HTS543225L9A300 uses?

August 8th, 2019, 2:02

Well, in the lack of documentation, I have to go the hardest way, figer out opcodes myself.
if anyone have more information about these Mitsubishi cores,
Please share
In return, I will share the results of my research here, and all of you will benifit.
thanks

Re: do anyone know which CPU Hitachi-HTS543225L9A300 uses?

August 8th, 2019, 19:21

Why not devote your effort to current helium models? ISTM that's where the commercial payback will be.

Otherwise, if you're just having fun, see the posts by @eaxi at hddoracle.com. He has done a lot of disassembly for the old Quantum drives, but his techniques, both software and hardware, should prove to be instructive.

Re: do anyone know which CPU Hitachi-HTS543225L9A300 uses?

August 9th, 2019, 8:30

Dear fzabkar,
thanks for your kind suggestion
I will definitely consider that.

Re: do anyone know which CPU Hitachi-HTS543225L9A300 uses?

August 9th, 2019, 8:45

OK, so I started on my own, and got some success.
like 0x2e is an opcode to read memory into a register
much like ldr r0,[r1]
its a 2 byte instruction.

Re: do anyone know which CPU Hitachi-HTS543225L9A300 uses?

July 8th, 2023, 8:22

@Spildit wrote: Hope that you did manage to make progress with your research !
https://www.hddoracle.com/viewtopic.php?f=21&t=2843

Thanks @Spildit,
yes I made much progress back then, but didn't shared it for 2 reasons:

1. I didn't make documentation of it because the cpu was so complex and it would have taken so much time.
I only made notes in primitive form because I wanted to make disassembler out of it,
if I shared, no one could have understood it.

2. During my research, I received 2 emails from ceo of two reputed companies,
(I previously asked them for docs, but they replied after 1 month)
One of them said that he will share it with business partners only.
I suppose he didn't have the docs.
The Other one said that some international agency have kept it secret for so many years(may be for good)
that no one in the world knows it.
I suppose he was right.
if I shared, it might have harmed the world in some unpredictable way.


Currently the hdd that has the research data stopped working.
it was in a drawer for almost 3 years, there is a constant sound of clicks for 2 minutes.
I managed to start its motor, but that doesn't have any effect on clicks.

Thanks everyone.
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