What is this CPU?

[fitzsteve]

Howdy!

My SSL A5000 board does not seem to have an 020 CPU which might well explain the crashing I get when trying to access the CPU, like with Sysinfo/showconfig :dry:

The CPU is badged up:

SC81160R16 and is the same Gold PGA package as a 68020 CPU, anyone know what CPU this is?

I can see 020 CPU's on eBay pretty cheap, is it worth grabbing one of those and swapping it over?

Cheers

Steve.

 

[lopos2000]

Maybe it's one of these ---> info

 

[Merlin]

@ Fitzy

If it was a 68020 with custom part numbering it would start SC41XXXXXXX and I don't think the one you have is a 68020.

If they can be had cheaply from somewhere it's worth a swap out.

 

[drutt]

My A5000 board has the same part number, and its what it shipped with (I got mine new in the dim as distant past). It was certainly marketed as a 16mhz 68020. I've not had mine working recently, but I think I remember it crashing sysinfo etc, but working fine in normal use.

Steve

 

[alexh]

SC = Special Custom
81160 = 68020 variant
R = PGA
16 = 16MHz

 

[roy_bates]

it is an 020 steve,just different markings.

 

[Merlin]

SC = Special Custom
81160 = 68020 variant
R = PGA
16 = 16MHz

Thanks Alex.

 

[fitzsteve]

Thanks guys

@drutt, any tips for whdload? It just locks up :-(

I still might try another 020 in case this variant is the problem?

 

[Gouldin]

Using my 020 on a 500 with 8mb ram, I had to use these tooltype for most games.

For most games, so I set these 2 as global.
NoVBRMOVE. NoAutovec.

And this one for the occasional game.
NoCache

Pretty much anything that wasn't AGA ran perfectly with just those options in whdload.

 

[drutt]

@drutt, any tips for whdload? It just locks up :-(

Sorry, only just noticed this question - I'm afraid whdload hadn't been invented when I last had my board working (still not had a chance to take the soldering iron to mine!)

Did you have you have any luck getting it going? I know on my A4000 with a Blizzard 4030 I have to use "NoAutoVec", as Gouldin suggests. Maybe worth trying "NoMMU" if you haven't already, as I also have a recollection of checking for an MMU being a reason Sysinfo etc crash.

Steve

 

[AndyLandy]

SC = Special Custom
81160 = 68020 variant
R = PGA
16 = 16MHz

Doesn't the SC prefix indicate a Signetics part rather than a Motorola one?

 

[alexh]

Not as far as I know. I thought that was SCN

http://cache.freescale.com/files/microcontrollers/doc/errata/MSE908AS60A_1L87J.pdf

Some MCU samples and devices are marked with an SC, PC, or XC prefix. An
SC prefix denotes special/custom device. A PC prefix indicates a prototype
device which has undergone basic testing only. An XC prefix denotes that the
device is tested but is not fully characterized or qualified over the full range of
normal manufacturing process variations. After full characterization and
qualification, devices will be marked with the MC or SC prefix.

 

[rkauer]

You'll have to put "NoMMU" in the global setting of WHDLoad, too. 020 CPU does not have a MMU unit.

 

[AndyLandy]

Not as far as I know. I thought that was SCN

http://cache.freescale.com/files/microcontrollers/doc/errata/MSE908AS60A_1L87J.pdf

Some MCU samples and devices are marked with an SC, PC, or XC prefix. An
SC prefix denotes special/custom device. A PC prefix indicates a prototype
device which has undergone basic testing only. An XC prefix denotes that the
device is tested but is not fully characterized or qualified over the full range of
normal manufacturing process variations. After full characterization and
qualification, devices will be marked with the MC or SC prefix.

Ahh, cool. Nice to have that clarified!

So, idle curiosity here: What's special/custom about this specific chip?

 

[roy_bates]

Not as far as I know. I thought that was SCN

http://cache.freescale.com/files/microcontrollers/doc/errata/MSE908AS60A_1L87J.pdf

Some MCU samples and devices are marked with an SC, PC, or XC prefix. An
SC prefix denotes special/custom device. A PC prefix indicates a prototype
device which has undergone basic testing only. An XC prefix denotes that the
device is tested but is not fully characterized or qualified over the full range of
normal manufacturing process variations. After full characterization and
qualification, devices will be marked with the MC or SC prefix.

Ahh, cool. Nice to have that clarified!

So, idle curiosity here: What's special/custom about this specific chip?

nothing,just the serial number.

 

[idr]

tl;dr: It's a 68EC020 with a 68020 pinout

tl;dr: It's a 68EC020 with a 68020 pinout

Sorry for reviving a long dead thread, but... I think I have solved the mystery about what actually makes this CPU "special."

I noticed that some versions of sysinfo detect this CPU as a 68ec020 while others (and other pieces of software) detect it as a 68020. For whatever reason, M-Tec wanted to make 68020 and 68ec020 versions of this accelerator using the same board. The one pictured on amiga.resource.cx has a proper 68020, for example.

After a quick bit of net searching, you can see that the pinout of the MC68EC020RP is DIFFERENT than the pinout of the MC68020R. You can also easily find instructions to build a 100-pin to 114-pin adapter so that a MC68EC020RP can be put in a MC68020R socket. Rather than do that, it seems M-Tec just had Motorola make a "special" 68EC020 with the MC68020R pinout.

It also means that if you, like me, have one of the special CPUs, you can't use M-Tec's AddMem32 to put the 32-bit memory at 0x01200000 and enjoy 4Mb 32-bit memory and 8Mb 16-bit fastmem. oh: You're stuck with 4+4.