Thanks Guys..... Sussing it out now, slowly !! I just had a quick prod...... Still no luck with the fluke checksums/sigs though so I kind of do suspect that it does do something different.... Heres what I've found out so far..... For the 64K roms (well two of them) From the 'mame generated info' we have ..... 0 - FFFF Rom 1 1 - 10000 Rom 2 This is actually a little misleading.... These roms actually sit at addresses 0 > 1FFFF and not 0000 > FFFF ( So I was at least right about doubling stuff and my schematics unscrambling was right !!!) and they are paired up to give a 16 bit data bus, just like the schematics show.... Fluke only lets you read EVEN adresses... so 00000 is ok , but it doen't like 00001.... So..... 00000 read gives 2 Eproms adr 0000.... 16 bit value... xx yy ... both 8 bit roms .. didn't check which was high and which was low 8 bits though sorry...... 00002 read gives 2 Eproms adr 0001 10000 read gives 2 Eproms adr 8000 10002 read gives 2 Eproms adr 8001 through to 1FFFE.... Eprom adr FFFF 20000 read gives next pair of eproms adr 0000 etc..... So... at least I'm getting somewhere understanding the beast now.... lol.... Now its got me wondering if I've only tested HALF of the Ram memory space usinng the mame generated info... !!! - I'll try that next......;-) Cheers, Colin ----- Original Message ----- From: "Mike Coates" <mike@the-coates.com> To: "Technical Tools Mail List" <techtoolslist@flippers.com> Sent: Wednesday, June 09, 2010 10:44 PM Subject: Re: [Techtoolslist] Fluke 9010a 68000 Pod Eprom TestingonOutrun- help please !!
If a 68000 system uses 8 bit roms then they will be interleaved in the memory map, hence generating the rom signature for just the 8 bit rom on it's own is not going to match.
I guess it either uses a different algorithm, or you need to interleave the two roms, and generate the checksum for the new double sided rom.
biggest pain I found with the Fluke pod is that you can only do 16 bit read/writes - I had some hardware that had a custom chip that processed 32 bit writes, so had to 'poke' some machine code in to ram and call that to do the job.
On 09/06/2010 21:29, Colin Davies wrote:
OK... That kind of makes sense.....When I get my pod pluged into the working board again (once I've fixed the header) , I'll try to do some homework !!!
eg.... read location 0000 in.... and see if its 16 bits and the pair of 8 bits matches the first bytes of both roms :-)
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