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Delving inside an A9home

By Chris Williams. Published: 25th Jun 2005, 20:43:01 | Permalink | Printable

First look at how Ad6 crammed so much into such little space [Updated]

A9home motherboardPhotographs of the inside of an A9home have this evening arrived in drobe.co.uk's inbox. A RISC OS software programmer who wished to remain anonymous managed to dismantle the hardened case of the ARM9 powered computer and document its internals. The machine, developed by AdvantageSix and Simtec, is available only to paying developers and is currently in the beta stage of development.

The packed motherboard, designed by the same engineers who crammed the electronics onto the Unipod, has in the top right corner an Asix Ethernet chip, as used by the Unipod, and a Silicon Motion SM501 graphics processor in the centre. The various unused header pins on the PCB provide access to the sound system, an LCD interface, serial ports and other input/output iterfaces provided by the system's chipset. There also appears to be a connector to what is possibly some NAND based Flash memory.

A9home motherboardThe A9home motherboard with glue logic, the chipset and various connectors. The computer including case measures 168 x 103 x 53 mm (about 6.6" x 4.1" x 2.1") and weighs around 550 grams.
A9home motherboardThe hard disc on the reverse side of the motherboard. There appears to be no need for cooling in the device.
A9home processor daughterboardS3C2440 400Mhz CPU module card with 128M of 133MHz Mobile SDRAM RAM, NAND Flash memory, and a lot of I/O.

The A9home owner said he tried to swap the amount of memory fitted to 256M although the machine then allegedly failed to boot. The photos have been censored slightly to ensure that no distinguishing marks can be used to identify our source. AdvantageSix have previously turned down requests for photographs of the A9home internals.

Update at 16:13 26/6/2005
We've been advised that the A9home motherboard and daughterboard are both static sensitive, so do take care if you take it apart - which is entirely at your own risk. We've also learnt that the Samsung ARM9 CPU is actually on the custom memory module that plugs into the white SODIMM socket located in the centre of the motherboard. This card carries the processor, surrounding glue logic, and the SDRAM and NAND memory - which explains why swapping out the module for a normal 256M RAM stick resulted in a dead machine.

Funnily enough, you can find such an integrated module on Simtec's website, which we understand will shortly be available with Linux 2.6 kernel support and Simtec's custom bootloader for embedded applications. The thumbnails above now include a link to official photographs of the processor module.


A9 website S3C2440 module card photos sourced from the Simtec website.

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Great. The pics confirm the memory and hdd can be changed. Planning to up the memory in mine and change the hdd to a 60Gb 7200rpm hitachi hdd during the next few months.

 is a RISC OS Usersa110 on 25/6/05 9:47PM
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Would be nice for instructions in how to get inside. I do have my own ideas of course, but until I am in a position to purchase the memory and hdd I am not going to attempt to take mine apart.

 is a RISC OS Usersa110 on 25/6/05 9:50PM
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Is it my eyesight, or is the serial port missing from the first picture?

 is a RISC OS Usersa110 on 25/6/05 9:53PM
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The serial port is, I imagine, just a connector on the back panel with a ribbon cable to the black 10-pin IDC socket that you see far left in the first picture.

 is a RISC OS Useradrianl on 25/6/05 11:00PM
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I'm wondering where the IDE connector is? (is there one?) Is there any way of fitting a standard floppy drive? (Not essential, but a lot of RISC OS software still comes on them) Cheers!

 is a RISC OS Userfwibbler on 26/6/05 12:02AM
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In reply to fwibbler: It is not a standard IDE connector that you see on the RISC PC/Iyonix or x86 desktop motherboards.

The hdd connector is quite clearly seen(I beleive) at the bottom of the hdd in the second picture.

 is a RISC OS Usersa110 on 26/6/05 12:14AM
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In reply to A9Home owners Is there any way to build an internal USB connector inside?

 is a RISC OS Userdatawave on 26/6/05 1:59AM
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Fwibbler, it appears SA110 is correct. Checking specs for this HDD, that is the ide connector. Is standard 2.5" device 44 pin connection with the usual 40pin IDE signal connections plus four pins for powersupply. the black plastic visible is likely to be a female connector directly on the motherboard - no cable needed as somebody has done a nice tight design. You will need a male plug at the end of your standard IDE cable to connect into this, probably buy a gender changer cable (high density IDC male -> ordianry IDC male) and then plug a standard 40way cable into that. I have played with many compaq/dell boxes that use slimline laptop CD-ROM drives with the laptop style 44pin ide connector, and they drive multiple devices fine - so long as you don't expect the weedy little power on the 4 extra lines to drive them. I'd like to see the option of a CD-ROM in the final puplicly released system - or at least the option as I don't want my new RISC OS machine limited to kiosk duty.

 is a RISC OS Userlostamarble on 26/6/05 3:24AM
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After seeing the HDD lottery with the Mac Mini it's nice that the A9 has 5400RPM. I hope this is also true of the consumer model as well.

 is a RISC OS UserJohnB on 26/6/05 8:44AM
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Isn't it clear that nothing extra will fit in there? Extra floppy, hard or DVD drives will need to be external via USB.

 is a RISC OS UserJaco on 26/6/05 10:51AM
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I do hope everyone listened to Ad6 when they talked about "no user access" and "warranty restrictions". As I understand it they can only keep the price down by knowing exactly what is inside the case and what can have been done to it. That means no internal modifications though, with 4 external USB ports on top of mouse and keyboard ports, there is plenty of chance to extend externally. And before lostamarble gets too disheartened by this he should take a look at the USB CD/DVD reader that STD released just before the A9 which is a better option than trying to fit a drive into a space less than 2" x 4" x 6.5" ;-)

 is a RISC OS Userjc on 26/6/05 10:54AM
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jc: Did you realise what this article is about? It is about Delving inside an A9home ... It has to be done, wether you like it or not ;)

 is a RISC OS UserhEgelia on 26/6/05 11:03AM
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hEgelia: Odd comment! I spent years telling kids that they needed to know what went on inside their computers and spent my own money on parts for them to see. I like the idea of letting everyone see what's inside the machine - but it's not right to encourage anyone to do it without a cost warning.

 is a RISC OS Userjc on 26/6/05 11:25AM
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sa110>Wrote the picture confirms the memory and HDD can be changed.

The latter almost certainly yes, but the former may take a little further checking, the article does say "The A9home owner said he tried to swap the amount of memory fitted to 256M although the machine then allegedly failed to boot". This could either be because the RAM he used wasn't exactly the right spec or perhaps the OS is set to only use 128MB or perhaps there isn't a full set of tracks to the RAM DIMM module socket.

The photograph is rather interesting, looks like Simtec toyed with the idea of supplying 2 full IDE sockets (they are the two unpopulated ones lower centre of the board). If those *had* been filled and useable the A9 would have made a proper desktop computer. I am (of course) assuming that the IDE tracks run to the empty socket holes. Pity, it means people need to use USB for any extra storage (at a speed cost) and a loss of functionality (CD/DVDBURN does not *currently* support writing on USB).

Nonetheless an impressive looking board (hard to credit that so much can be squished into such a small place).

jc> Perhaps if Ad6 had chosen to "publish" official photos no-one would have been tempted to open one up voiding their warranty? Can't understand why they didn't - it's not as if someone could "reverse engineer" one from the photo. Being a hardware geek I am always keen on seeing the innards - leaving the motherboard a mystery just encourages people to open 'em up - as in this case.

 is a RISC OS UserAMS on 26/6/05 3:08PM
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Chris> Thanks for the clarification/update.

Yep with the processor on the RAM module simply swapping the module is *not* an option and the machine will *not* boot. Effectively it means that the A9 can *only* be upgraded if Simtec/Ad6 provide an upgraded processor card that contains more RAM and the obligatory ARM9 processor. Interestingly it may leave open the possibility for future processor upgrades.

 is a RISC OS UserAMS on 26/6/05 4:10PM
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In reply to AMS: Looking at the memory module on the Simtec website suggests that the module is not available with more than 128MB ram.

In reply to Jaco: I'm aware that the supplied case is too small for upgrades. That wouldn't stop me putting the whole thing into a more standardised PC case with room for internal CD, Floppy, Flash card reader, etc.... I've never understood the fasinationwith external devices. All those extra cables, very untidy, Ugh!

In reply to Lostmarble: Thanks very much for the info. Cheers!

 is a RISC OS Userfwibbler on 26/6/05 4:27PM
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The specification on the pages linked in the article, do say it can come with upto 256Mb RAM.

 is a RISC OS Usersa110 on 26/6/05 4:45PM
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It really is dissapointing to find you cannot upgrade the memory in it. Allthough the prospect of a combined processor and memory upgrade option is certainly favourable.

 is a RISC OS Usersa110 on 26/6/05 4:50PM
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But still at least I can upgrade my hdd at a later stage. 60Gb 7200 rpm drive weighs in at about 105 from Misco.

 is a RISC OS Usersa110 on 26/6/05 4:51PM
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In reply to sa110: I stand corrected on the memory thing. Whether the A9home will have a 256MB module as an option I don't know. I would hope so. I'm still toying with the idea of getting one. Cheers!

 is a RISC OS Userfwibbler on 26/6/05 11:27PM
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AMS, I suspect you'll find those two 50 pin solder pad areas at the bottom are more likely to be a bus implementation so that the hardware can be tested or added functionality can be 'easily' added by plugging in another card - like the lart+kitchensink board. There does appear to be an internal USB header, so internal USB devices is a very good posibility.

Gee, I had just gotten used to having all my disc drives inside my computer, I guess with this system we should expect to see a return to the good old BBC micro days - cables to the tape deck, cables to the floppy drive, cables to the 2nd processor and any other device you have plugged in, and power supply cables for them too, I just loved a my cluttered desk and miss it sooo much :o)

If these are developer machines, we should not expect final shipping product to be identical as feedback is collected and fixes/requests are ammended. I don't know if I am too spoiled, but I would not expect a computer manufacturer to produce a computer system (even budget concious A9 design) and not give the user a removable media drive bay so that they can load software into their new toy. Surely the industry isn't going to take a giant leap backwards and expect new users to know what peripherals they need buy with a new computer? We're all going to be so busy telling people not give up on thier new A9, just go out and spend more money and plug something useful into it. The DVD drive in the mac mini makes it bigger, sure, but a whole lot more practical from a users perspective - I can load software patches as soon as i get it and keep it running healthy ;o)

 is a RISC OS Userlostamarble on 27/6/05 8:31AM
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Sorry if this has been answered elsewhere - but how is the OS stored? In ROM or flash ROM or on disc? Is it user-upgradable?

 is a RISC OS Userjms on 27/6/05 9:22AM
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Maybe a card reader for MMC, CF, etc. will be built in in the final version...

But even if this won't be the case, software vendors will probably adapt quickly and sell their stuff on USB key-drives.

Also the A9home will probably come with everything you need to connect it to the internet, and most software can be obtained online, anyway.

 is a RISC OS UserJGZimmerle on 27/6/05 10:08AM
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Ha .... USB ROM disc for installations..much quicker than CD :D and bigger than cd now :P

 is a RISC OS Userem2ac on 27/6/05 1:24PM
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What is needed is an A9Home Caddy which would be a rack mount to take the A9, PSU, Drieves etc all in one tidy box. The problem is how big to make it? Too small and it will have to come in slices ;-( too big and you might as well adapt a cheap Mini ATX case or even a standard ATX case :-(

 is a RISC OS UserHeloWorld on 27/6/05 1:25PM
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HeloWorld: It wouldn't be a A9Home anymore would it?

I believe there will be other computers in the A9 range that will forfill your needs. Can't find the page again but saw something about a 1U high 19" rack mountable A9.

 is a RISC OS UserJaco on 27/6/05 4:25PM
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lostamarble> Yes, I took them for IDE but you're right they 50pin rather than 44 (oops!), so your conclusions are not unreasonable.

I'd also agree that it would be a step backwards if the hardware is all "external" to the computer - but then the A9 is not a traditional computer given that it's origin is not a desktop but rather the embedded device market. For the cost concious or people who must squeeze as much of a computer into the smallest possible space it should do nicely, as a desktop it is probably more limited though - but who says that that should be the only paradigm that RISC OS should be aimed at ?

jms> The Processor/memory module has NAND Flash RAM (according to the Simtec site) so the OS (or a part of it) is probably stored there.

 is a RISC OS UserAMS on 27/6/05 6:37PM
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Being limited to 128 MB isn't *too* limiting. (I guess anyone wanting to edit huge bitmaps while running !firefox, would probably be better off with an Iyonix, but possibly an update to virtualise might be the answer for this anyway).

The lack of internal removable drives wouldn't be too bad either, I'd just use those on my RPC via the network. (Though the suggestion of an internal card reader is good).

The thing that puts me off it is the lack of a DVI socket. (If it had DVI, then it would provide the two things I'm waiting for on my Iyonix, this and adjustselect)

This makes it highly unlikely that I will replace my Iyonix with it, (thers's still a very slight chance I might buy one anyway,) If it had DVI, I think it unlikely I would be able to resist buying one at that price.

 is a RISC OS Userjess on 27/6/05 6:40PM
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In reply to Jaco:

My comments were meant to be somewhat sligtly light hearted. There were comments about the case not being big enough to house all sorts of drives and whilst the idea of an overall case would have some merit it is also probably a cost non-starter. (the mangling of ;-) to ;-( did not help after my reference to 'slices' as in RPC. If someone wants to use an A9 but in a single case then a cheap (10 ukp) PC box to hide it in would be the obvious route. :-) really ment this time.

 is a RISC OS UserHeloWorld on 27/6/05 6:58PM
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Nice article. Amazing what you can do with microchips huh? ;o)

I can't help looking back to the launch of the Iyonix and remember all the comments about its alleged 'lack' of upgradability......

Still as long as everyone is happy that's all that matters! ;o)

 is a RISC OS Userblahsnr on 27/6/05 7:02PM
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I don't think it would be very difficult to put An A9Home in an ATX case (still in its original box)

 is a RISC OS Userjess on 27/06/05 7:16PM
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@blahsnr: Well, this is not a traditional desktop computer, but (as the name suggests) is meant as a home computer, sort of in between the A3xxx- and the Ax000 Series. You would expect limited expandability from such a machine.

And in contrast to the Iyonix, the CPU is upgradable.

 is a RISC OS UserJGZimmerle on 27/06/05 8:42PM
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JGZimmerle: You mean replaceable.

 is a RISC OS UserJaco on 28/06/05 08:34AM
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Replaceable , upgradable , semantics for pedantics. If I "upgrade" the memory in my computer I replace the old memory. If I "upgrade" the hard drive I replace the old one etc etc.

 is a RISC OS Usermripley on 28/06/05 4:02PM
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Indeed semantics for pedantics but still there is some difference.

What I mean is:

You upgrade when you put something better in, more memory, bigger hard drive, extra or faster processor, etc.

Theoretically you could upgrade the Iyonix CPU (With CPUs on a PCI card but there's no support), also theoretically you could upgrade a A9Home (Replace the CPU/Memory piggyback with a faster one but that's not yet available) so there is no real difference there.

However you can not replace the CPU of an Iyonix as that is soldered to the board.

 is a RISC OS UserJaco on 28/06/05 4:37PM
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JGZimmerle>"You would expect limited expandability from such a machine. And in contrast to the Iyonix, the CPU is upgradable. "

and Jaco>"Theoretically you could upgrade the Iyonix CPU (With CPUs on a PCI card but there's no support)...however you can not replace the CPU of an Iyonix as that is soldered to the board. "

Notionally you can upgrade the A9Home's CPU and RAM, I'd point out currently the version supplied is the fastest available. There may also be limitations on the level of upgrade that might (even theoretically) be possible - for example does the CPU card offer a 32bit or 64bit databus (if not 64 it either won't support xScale or will require further glue logic and a performance hit). There's also the *cost* factor, if the cost of the add on is such that the machine becomes as expensive as an Iyonix you'd be wiser buying an Iyonix !

Also in some instances (as Jaco said) some upgrades are theoretical and remain so (the much vaunted 1GHz xScale that fits to the Omega springs to mind ;).

Yes the Iyonix is limited in that the CPU can't be upgraded, neither is the A9 upgradable at the moment (and the available upgrades may not lift it above the Iyonix in performance terms in any case). In it's favour the Iyonix has genuinely useful features like *currently* being able to take 1GB of RAM (8 times that of the A9) and being able to host 4 IDE devices and have more add on's than you can shake a stick at. So in applauding the acchievement that is the A9 let's not go knocking the Iyonix it still is the "gold standard" of RISC OS computers....

 is a RISC OS UserAMS on 28/06/05 6:42PM
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"So in applauding the achievement that is the A9 let's not go knocking the Iyonix" Quite right. We are nowhere near being able to do any real comparisons with other machines as no-one has yet seen a retail A9 never mind using one. All we can really celebrate at the moment is its existence. Much more (pro or con) could easily be blown out of the water by the real thing. Though the speculation is fun! ;-)

 is a RISC OS Userjc on 29/06/05 2:20PM
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I hope, they make the released A9home USB 2.0 compatible, if they do, then you can backup the software on the inbuild HD on a USB 2.0 Monstor drive with a capacity of 4 GB. Have a look at the next url, how this drive is look alike : [link] - This is a REAL piece of RISC OS backup facility on such a small device.

 is a RISC OS Userdatawave on 13/07/05 02:08AM
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datwave: I'm not sure you've paid much attention to what's been said. It _can't_ be made USB 2.0, for reasons already stated. Regardless of that, it can be used anyway (filing system issues not withstanding), since such a device would be USB 1.1 compatible.

 is a RISC OS Usermrchocky on 13/07/05 09:27AM
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Datawave: just order a couple of thousand A9's with USB 2.0 and I expect they will be build for you. If you want less, you get less, so stop ####.

 is a RISC OS Useregel on 15/07/05 12:09AM
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You'd probably need to order more than a couple of thousand - and you'd be probably waiting a while. It (judging from Peter's contribution) is a *hardware* issue. The board simply does *not* contain a USB2 compatible controller. To replace it would mean a substantial board redesign (there is *no* other option as the A9 has *no* means to allow an external USB2 card to be fitted). The board and OS would need to be updated and then the thing tested and then after any further revisions a new board complete with USB 2 would be issued. I *can't* see that happening with the current design.

It isn't Ad6 and Simtec being awkward - it's just that technically and economically having taken this project so far it would not be possible to change it over so late in the day into a USB2 based unit. It would probably make more sense (if the A9Home is successful) to follow up with an A10 (or something) in a year or twos time with the A9's shortcomings addressed.

 is a RISC OS UserAMS on 15/07/05 6:56PM
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USB is back and upward compatible so although it isn't USB2 the A9Home is USB2 compatible!

 is a RISC OS UserJaco on 15/07/05 8:47PM
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Jaco> Just to clarify, no USB is is *not* upwards compatible, it is *backwards* compatible in that a newer controller/device can "fall back" to the slower speed and still talk to an older device (at the older device's speed). The USB2 device slows from 480Mbps to 12Mbps (USB1.1) to suit the *older* device - in this case the A9Home.

 is a RISC OS UserAMS on 15/07/05 9:56PM
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