[Techtoolslist] Fluke 9010a 68000 Pod Eprom TestingonOutrun- help please !!

[Colin Davies]

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 at the-coates.com>
To: "Technical Tools Mail List" <techtoolslist at 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 :-)