Identify microprocessor from code.

are you sue the date you listed is code ? i do not think so, i think storing the code in a eeprom is a bad design if you want identity this microprocessor, maybe you should find some hint from it's pins and the mark on it surface.

Simon

It is a 4meg EPROM , And it is a very common design. I am not sure how you can tell what the CPU is from a hex dump.

You have no way of identifying what is code, and what isn't. Also, do you know if this EPROM was half of a 16-bit wide ROM image - 4Mb is a lot for an 8-bit design)? And does the board use some sort of design protection, eg. scrambling bit lines or decrypting EPROM data using a PAL? Do you have schematics?

Also, some manufacturers supplied custom variations of micros with masked bootstrap roms and even built-in encryption, most of which also had custom part numbers.

For some common micros, an experienced disassembler with enough data can recognise code areas of his/her favourite micro (eg. I could probably do so with Z80 code), but with so little info and (I'm assuming) experience I don't like your chances.

Regards,

Oh one can if one speaks the language. Or has spoken it, that is... I would have known instantly if it had been a 6800 or a 6809 - although I have not spoken much of these languages for well over a decade. So it is not one of these (and not a HC11 either, which is an enhanced

Didi

------------------------------------------------------ Dimiter Popoff Transgalactic Instruments

------------------------------------------------------

Original message:

Take a picture of the board, put it up on the web somewhere, and link to it.

The support chips, or board layout may give enough of a clue to someone experienced with the board.

When the choice is minimal, some decent answers may fall out.

Don...

PowerOne a écrit :

H8300, possibly

Looks a bit like Hitachi H8! (5470 == RTS, 6D7{0x} POP, 6DF{0x} PUSH. )

Why would storing code in EEPROM be bad design? Furthermore, this code is stored in EPROM (one 'E'). This used to be the defacto standard for storing code until FLASH chips and controllers with big internal FLASH became common.

Starting from 500h sound a bit funny though, most CPU's start executing from zero or from their highest address.

If there was any deliberate attempt to hide the type of processor or otherwise hinder reverse engineering, data- and addressbusses may have been mixed up as well.

I will try to get the picture. The package type is TQFP (Thin Quad Flat Pack) I don't have schematic.

Hitachi has a Mark but this one don't.

This makes no sense. If you want to post a followup via groups.google.com, ensure you quote enough for the article to make sense. Google is only an interface to Usenet; it's not Usenet itself. Don't assume your readers can, or ever will, see any previous articles.

More details at:

Why do you think that it is code, not just data in the eprom? Could the micro have on-chip rom/flash?

Ok, so whats on the outside of the box.

Did you just get a PCB without a box/case and power supply ??

donald

It would be reasonable for a 80C196 variant. The reset address IIRC was

Robert

The board is from an Archade machine made in Spain.

I think it's kind of a fun question actually. Almost worth posting some examples as intentional challenges to the group just for the fun of it.

Sure, their are snippets that would be undecipherable, or very difficult such as half of a 16 bit pair as mentioned, but I bet many real world examples could be identified. At least by ancestry if not by precise variant.

Do you mean "arcade"? Whay didn't you say it was so important earlier??? I'm assuming this particular machine isn't yet implemented in MAME?

A *lot* of arcade boards (depending on the era) used varying degrees of design protection, ranging from simply switching address/data lines or a simple xor-matrix PAL to custom encrypting processors with volatile key storage. Cross your fingers it's not the latter! ;)

I'd run with the H8 suggestion first. Run it thru a disassembler and see if there are any areas that look sane (start with the reset vector address of course). However, I'm pretty sure that there were a number of machines that used custom Hitachi processors for design protection. Is this the main game processor? I don't recall any games using H8 off the top of my head (I could be wrong), but rather using H8 parts as secondary processors for I/O controllers...

Regards,

Here's another way of looking at the data given. Hope it helps.

01 00 6D 76 52 E6 09 5E 54 70

01 00 6D 76 55 5C 0F D6 54 70

01 00 6D 76 0F E6 4B 0C 0F D5 4A 10 17 B5 55 42 17 B6 54 70 17 B6 0F D5 4A F4 17 B5 40 34

01 00 6D 76 0F E6 4B 0C 0F D5 4A 02 17 B5 55 1E 0F D6 54 70 17 B6 0F D5 4A 02 17 B5 55 10

Do you have an ohmmeter, pencil, paper, and time? If so, you can generate a schematic. The old Tocom/General Instruments 5503 cable box had a house numbered processor. I drew a schematic and then compared it to all the standard micro pinouts I could find. Turned out it was a Zilog Z8, and the address/data lines were scrambled.

Even a partial schematic showing the CPU to memory connections can be a big help.