A confused A7000

Arc/RPCs, peripherals, RISCOS operating system & ARM kit eg GP2x, BeagleBoard
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sh0dan
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A confused A7000

Post by sh0dan » Wed Oct 09, 2019 9:28 pm

I've been going back through the motherboards I have to see if any work and found this one which confuses me... although that is easily done :D

Its an A7000 board, 4mb memory but it looks a little different to the others:
* The board is a lighter shade of green with more distinct white print on it.
* The RISC OS boot screen (ROM chips?) is branded "Acorn Risc Technologies". Googling indicates they sold A7000's so I guess this is expected.
* The boot sequence and supervisor prompt tell me its got an ARM 710 processor? It has issues. It boots through purple/blue/red before eventually ending up at a desktop with delete held down for what seems like an eternity, so that could be a hardware fault. The board clearly says its an ARM7500 processor.

I just wondered if anyone knew if A7000's ever came with a "ARM 710 processor" or if I was misunderstanding and a 710 and 7500 were the same?

Thanks
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danielj
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Re: A confused A7000

Post by danielj » Wed Oct 09, 2019 9:30 pm

The ARM7500 is basically a 710 System-on-a-chip (a-la ARM250 so has all the IOMD and VIDC built into it), so as far as the OS is concerned it's a 710 :)

d.

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Re: A confused A7000

Post by sh0dan » Wed Oct 09, 2019 9:40 pm

danielj wrote:
Wed Oct 09, 2019 9:30 pm
The ARM7500 is basically a 710 System-on-a-chip (a-la ARM250 so has all the IOMD and VIDC built into it), so as far as the OS is concerned it's a 710 :)

d.
Thanks for the quick reply, that makes sense.

I wondered why it stood out. Guess the others boards don't print it so I hadn't seen it before :)
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steve3000
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Re: A confused A7000

Post by steve3000 » Wed Oct 09, 2019 10:26 pm

sh0dan wrote:
Wed Oct 09, 2019 9:40 pm
I wondered why it stood out. Guess the others boards don't print it so I hadn't seen it before :)
The others probably have RISC OS 3.6 in that case?

RISC OS 3.7 introduced the Advanced Risc Technologies boot screen, along with the processor display at startup.

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Re: A confused A7000

Post by sh0dan » Wed Oct 09, 2019 10:30 pm

steve3000 wrote:
Wed Oct 09, 2019 10:26 pm
The others probably have RISC OS 3.6 in that case?

RISC OS 3.7 introduced the Advanced Risc Technologies boot screen, along with the processor display at startup.
Ah yep, that is the case.

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davidb
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Re: A confused A7000

Post by davidb » Thu Oct 10, 2019 12:49 am

Strange. The A7000+ doesn't have an ART boot splash screen like that. I wonder if the ROM is a replacement from another system.

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SarahWalker
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Re: A confused A7000

Post by SarahWalker » Thu Oct 10, 2019 10:20 am

The A7000+ was released after ART was closed iirc, so the relevant RISC OS (3.71?) doesn't have an ART banner. This machine looks to have been upgraded to 3.7, though I had thought that version could detect the ARM7500.

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Re: A confused A7000

Post by hubersn » Thu Oct 10, 2019 1:48 pm

SarahWalker wrote:
Thu Oct 10, 2019 10:20 am
The A7000+ was released after ART was closed iirc, so the relevant RISC OS (3.71?) doesn't have an ART banner. This machine looks to have been upgraded to 3.7, though I had thought that version could detect the ARM7500.
The original A7000 was shipped with RISC OS 3.6 IIRC, so I would guess that 3.70 should indeed detect the ARM7500. Not sure about 3.6 however, which was the version for the Risc PC 7000 before the A7000 was available - again IIRC.

Have fun
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sh0dan
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Re: A confused A7000

Post by sh0dan » Tue Oct 15, 2019 10:16 pm

SarahWalker wrote:
Thu Oct 10, 2019 10:20 am
The A7000+ was released after ART was closed iirc, so the relevant RISC OS (3.71?) doesn't have an ART banner. This machine looks to have been upgraded to 3.7, though I had thought that version could detect the ARM7500.
Apologies for the delay in replying. I also have a partially working A7000+ board and a single A7000 case marked with "RISC OS Ltd" and "RISC OS 4.5 Demo". Unfortunately I don't know if the roms were switched.

The A7000+ has an unbranded RISC OS 3.7 boot screen and does recognize the processor as "ARM 7500 FE Processor" on boot.

Not sure if that make anything clearer?
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Re: A confused A7000

Post by sh0dan » Tue Oct 15, 2019 10:20 pm

davidb wrote:
Thu Oct 10, 2019 12:49 am
Strange. The A7000+ doesn't have an ART boot splash screen like that. I wonder if the ROM is a replacement from another system.
I love playing with them but am not very good with Acorns, however I believe the original (ART) pictures to be from an A7000 board and not an A7000+. While I do also have an A7000+ board as mentioned above. For example it only has 4mb ram.

Ignore me, sorry I misunderstood when I first read it.

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Re: A confused A7000

Post by sirbod » Wed Oct 16, 2019 4:59 am

The A7000 comes with the ARM7500 which is an ARM700c series core, either it's CPUID isn't unique (I don't have one to check), or the OS doesn't have an explicit entry for the ARM7500. Either way, the ARM7500 and ARM710 (ID 41007100) have a similar CPU core as the ARM710 has an ARM700a core.

The A7000+ comes with the ARM7500FE which is an ARM700 series core with FPU. It definitely has a unique CPU ID (41077100) and I believe required an OS update from the one shipped in the A7000.

Interesting, I found an apparently undocumented erratum in the ARM700 core a few years back, which I covered here.

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davidb
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Re: A confused A7000

Post by davidb » Wed Oct 16, 2019 10:21 am

Sorry to confuse things about the A7000+. My point was that the A7000+ didn't have that splash screen and I expected the A7000 and A7000+ to have similar ones. I would have thought that the ART logo was only used for certain upgrades.

The ROMs that I use in RPCEmu are for RISC OS 3.71 (19 Feb 1997), though I'm not sure if I read them from my A7000+. That's the version I remember using on the real hardware. I think the extra 0.01 over version 3.70 covered the new CPU.

According to 4corn's page on The Acorn Risc PC and A7000, the A7000 shipped with RISC OS 3.60, so I would think that the ROMs in sh0dan's A7000 are replacements from a StrongARM Risc PC. The two ROMs are in the photo show 3.70 (1996) so I think this seems likely.

It might also be interesting to drop to a command line and get the output of this command:

Code: Select all

*help UtilityModule

sh0dan
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Re: A confused A7000

Post by sh0dan » Wed Oct 16, 2019 5:57 pm

davidb wrote:
Wed Oct 16, 2019 10:21 am
Sorry to confuse things about the A7000+. My point was that the A7000+ didn't have that splash screen and I expected the A7000 and A7000+ to have similar ones. I would have thought that the ART logo was only used for certain upgrades.

The ROMs that I use in RPCEmu are for RISC OS 3.71 (19 Feb 1997), though I'm not sure if I read them from my A7000+. That's the version I remember using on the real hardware. I think the extra 0.01 over version 3.70 covered the new CPU.

According to 4corn's page on The Acorn Risc PC and A7000, the A7000 shipped with RISC OS 3.60, so I would think that the ROMs in sh0dan's A7000 are replacements from a StrongARM Risc PC. The two ROMs are in the photo show 3.70 (1996) so I think this seems likely.

It might also be interesting to drop to a command line and get the output of this command:

Code: Select all

*help UtilityModule
My fault! It was late when I read the message :) Thanks for taking an interest.

The output is pictured underneath.
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MosUtility.jpg

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