Why and when flash memory is needed in embedded system?

At least one of the IBM S/360 series (I _think_ it may have been the Model 40) had its field-upgradable instruction-set-defining microcode stored in "transformer-based" ROM known as "TROS" (transformer read-only storage). The "windings" were conductive patterns embedded in a plastic strip with square holes for the cores; Engineering Changes could be done on-site using a small leatherpunch-like tool to "cut through" some of these traces and leave others intact.

IIRC the Model 30 used CCROS (capacitive) which used a grid of conductive pads on a plastic sheet the same size and layout as the standard 80-column punch card. _These_ could be programmed using... (you guessed it!) the IBM 026/029 keypunch. Since an 80-column card had 12 rows of holes (960 bits), and since (IIRC) there were only

1/4 as many CCROS pads, that's 240 bits/card; this on a plastic card that occupied roughly the same volume as 2 CF cards (16Gb by now?).

By the time the S/370s came along (and IIRC some of the later S/360s) IBM had moved on to 8"-floppy loadable microcode (160,000 bytes!!).

We've come a long way, in this area, at least.

Frank McKenney, McKenney Associates Richmond, Virginia / (804) 320-4887 Munged E-mail: frank uscore mckenney ayut minds pring dawt cahm (y'all)

-- "Progress, far from consisting in change, depends on retentiveness-- when experience is not retained, as among savages, infancy is perpetual. Those who cannot remember the past are condemned to repeat it....This is the condition of children and barbarians, in whom instinct has learned nothing from experience. -- George Santayana, Life Of Reason (1905)

--

The price could be what swings it - it is certainly not a technically competent as the PSP but I'm sure it wipes the floor with gameboys and DS's.

What is needed is for someone to make it a bit more friendly to people who just want to play games and then it could take off in a big way. However, I think it needs another iteration of hardware development to be a success. I'm not convinced that the board space and power taken up by the TV-out circuitry can be justified either.

Of course, the tinkering to make it work brings in another type of fan. I wouldn't dream of buying a PSP because I'm not a gamer but something that needs to be cajoled and poked into working.... ohboygimmegimmegimme :-)

The TV-out circuitry certainly can't be justified - it is in a format unsuitable for many TV's (S-Video), the TV adaptor is expensive and uselessly short, meaning you have to buy expensive extension cables, and the quality varies from very poor, through black-and-white only, to absolutely terrible, depending on the game.

The GP2X itself is a great device, and fun for a hand-held games machine (it's popular with the kids, and fine for the odd game of SuperTux). But don't even consider the TV Out.

I wasn't planning on getting the TV-out cable but I definitely won't now. The breakout board that Game Park now sell is a great idea and is the perfect place to have the TV-out circuitry although VGA would be much more sensible.

Whilst I don't game very often, I have found the few I've tried to be pretty good, if a little rough round the edges. The emulators are where I'm at at the moment but I need to get squidgeSNES to work smoothly on mariokart (the release of which, of course, was the greatest event to have happened to the earth) before I can concentrate enough to fully drown out the girlfriend's yapping.

I wonder whether a wi-fi USB dongle would work on the breakout board? Would be nice to be able to stream movies off my server whilst in the bath/garden/locked out on the doorstep.

Talking of price, I see your new book is now available in Amazon UK and is only £16.49 and has free delivery. You might have made a sale there, particularly because I just get paid today and I'm going to be doing drunken internet shopping tonight :-)

I always found it amusing that the VAX 11/780 came with a PDP-11 stuck inside the cabinet. Not a PDP board, but the entire computer, case, toggle switches, etc (the VAX itself had very few blinkenlights on the outside. The PDP's job was basically to load the microcode and boot start the VAX, and it also served as the console.

-- Darin Johnson

Oh yes Mario Kart, I remember playing that game on ZSNES for DOS on my Cyrix 6x86 133Mhz. The game has some DSP embedded in the cartridge for the pseudo 3D. Took a huge performance hit on my 133Mhz. I could barely hit 30fps on the best of things.

-Isaac

How is the battery life on the 2X? I was contemplating purchasing one maybe. The Zire 71 is for sure a bit more compact than the GP2X but it doesnt have nearly as much horsepower or video hardware. I use it as a MP3 player haha, it also has a built in camera, but its resolution is

640x480 so the pics aren't exactly top quality.

It is based on a TI OMAP310 SoC (ARM9 @ 144Mhz). I havent seen any TRUE

3D games on it since I have to pay money for 3D games and I am certainly not doing that ;).

I just was flipping over the PalmOS v5.x.x documentation. As it so happens the majority of applications are still compiled for the M68K derivative that was in the older Palms (VII, V, etc.). For places where there is a need for performance they can be written in native ARM code (as "ARMlets") which you can invoke from the M68K code. Tons of example code and a relatively well documented API. Though the PalmOS Developer Suite is a ~400MB download :-O!

I admit I am a heavy gamer, so I have both the PSP and the DS Lite. But neither architecture is as "open" so to speak as the Palm or the GP2X.

That'd be neat! If I recall I don't think anything like that has been made for the GP2X. Mostly high quality 2D games (which are not bad at all).

That seems like a good use for the GP2X. You must have a big SD for the Sopranos episodes? I like the Sopranos as well. My Zire 71 probably doesn't have the horsepower to play anything like that buy my PSP for sure could.

-Isaac

When I was working in Saudi (in Riyadh on the air traffic system), we had, in one particular shack full of equipment, a Rolm communications control processor. This was about 25 years ago :)

This device had 16 adddress switches (helpfully labelled '0' and '1' ;) , 16 data switches also helpfully marked, a spring loaded 'load' switch and a switch marked 'Run'.

The power up for this beast was to set address 0, set the data switches appropriately from the manual and hit the 'load' switch. repeat at successive addresses until the required 64 words were loaded.

Move the run switch to the RUN position. The 64 instructions were the tape reader init code so it could boot from tape.

and people complain about boot times ;)

Cheers

PeteS

The battery life is one of the weaker elements. The alkalines it came with lasted about 45 minutes and I got about an hour out of the 1200mAh NiMH cells from my girlfriends camera (I'd probably better give them back soon). I bought some Uniross 2400mAh NiMH cells after that and now I get about 2 and a half hours watching movies. I bought 4 so that I can have one set in use and one set on charge or spare and, to date, I have never been caught without power yet.

I can't see anyone paying for games on an architecture where most are free. I guess if the games were really incredible and beyond the means of amateurs to write then there could be a small market but I think it would quickly be piratted into oblivion.

Seems like normal run-of-the-mill legacy support bloat. Why not write the whole application in an ARMlet and get it really moving? Of course ARMlets mean that legacy support is lost so they might as well just have copiled for ARM anyway. Suprised by the big developer download - presumably the installed app is even bigger. Hopefully that is 399Mb of examples and 1 of compiler.

The GP2X will appeal if you are into retro games but the native stuff is not all that hot really. Perhaps there will an increase in popularity soon.

There's Quake and Duke Nukem but I think that is only really pseudo 3D. I do have a SNES StarFox ROM which I haven't tried yet but it would be interesting to see how they handle the hardware accelerator that used on the original console. That sort of game would be a good place to start in developing some good fast 3D polygon movement. The ARM is probably powerful enough for a bit of texturing too. I guess it all depends on how much control you can have over the graphics processor and whether it is wired up sensibly.

I use a 1GB SanDisk SD card. A divX episode of the Sopranos comes in at about 350Mb but, after all the applications, ROMs and mp3s, I only have about 200meg free. The movie player is pretty fussy about what it will play and some divX films just won't work at all. I've got virtual dub and a number of other open source video processing/DVD ripping tools that the GP2X wiki recommends so I should be able to fix them once I work it all out. It would be nice to have mpeg support right out of the box but I guess there are licensing issues. To be honest, mpeg is such a popular format that it would be worth putting a few dollars on the rrp to cover but I guess it would go against the open source philosophy.

Does the PSP have better support? That weird little disc it uses seems like a good point of failure when watching movies but it does use those expensive memory cards as well which might alleviate that.

Tom Lucas schrieb:

Hello,

they needed personell which was able to handle very small ferrite beads and thin copper wires.

Bye

Perhaps my girlfriend should apply? ;-)

The way the PSP works is qutie strange with video. Some commercially released movies are available on the disc (UMD). But as usual, that is a Sony proprietary format and it did not take off too well. There has been announcements that the movie studios would stop releasing videos for it.

The PSP actually can only play MP4 files off the Memory Stick Pro Duo card. The PSP requires that these files be named in a certain obscure manner. The PC side software is responsible for transcoding it to the MP4 file. It's not too bad actually, my P3 1.13Ghz took about a minute or so to do a 40 sec MPG video. The quality of the video is quite good (assuming it scales well to the 16:9 aspect ratio). It makes an excellent MP3 player too and has good audio output. Also the GPU's output is quite impressive as well. Quite impressed with it.

-Isaac

I guess the bulk of the work is done by the PC then - does it have a fairly wide range of supported formats? I suppose you just have to leave it to Sony to get it onto the PSP unless you want to work out their mechanisms. This is what infuriates me about the iPod too - everything is proprietory and you have to go a long way out of your way to get around it. My plan for the GP2X is to get wireless LAN into it somehow and then stream movies from my server to wherever I am in the house. To have to convert all the movies into a GP2X format would be highly inconvenient and a waste of disc space.

The mp3 player on the GP2X is a little lacklustre. There are a variety of equalizer settings but it is not that brilliant and the compression is very apparent on deep bass notes.

Yup pretty much any format can be converted. I guess as long as you have the codec installed. The iPod, although a really nice player, is probably the last MP3 player I would ever buy. There are hacks available though so you dont have to use that iTunes application (which unfortunately is bundled with QuickTime player now). Maybe you can get an SDIO WiFi card for the GP2X? Maybe there is a driver available or something. My Zire 71 unfortunately doesnt work with most cards. Seems like only one card is listed as working.

I did use MMPlayer on the Zire 71 and it played a 160x160 video quite well, no dropped frames and quite smooth. I don't think that is too bad for a 144Mhz ARM9. There was some exaple 320x320 videos but I don't think those would go over too well. Might be worth a shot.

The GP2X looks like a bigger device so I thought it would have some good audio hardware. I remember looking over some code for the GP2X, the way it sets its output sample rate was quite strange, definitely don't remember it being standard way of doing it (setting up some clock divider).

The Zire 71 (DioPlayer app to be exact) has a graphic EQ. Once that is turned on though it becomes quite sluggish.

Though the Zire 71 also has some weak audio output. I hooked it up through a tape adaptor to the tape deck in my 1997 Volvo 850 (I believe). The bass was very weak almost non-existant. Now the sound system in this car is quite impressive for a stock system.

Your mention of compression reminded me of a discussion I had with a co-worker during my summer job. He does some music production so he was pretty knowledgable of audio technology terminology (filtering, etc.). He told me about a case in which he used "compression" and described what it does. But I must ask what is the difference between compression and attenuation?

-Isaac

Tell me about it, the girlfriend has a seperate WinXP login on which she has updated her iTunes (I try to keep is away fro my login) and the damn thing has smeared itself and quicktime over everything I hold dear. It's worse than the old AOL days when it used to take control of everything on your PC and your underpants if you stood too close.

Might be an option. The breakout board allows a USB dongle to be used too - assuming that the driver can be made to work. Perhaps an SDIO WiFi could be an idea and I'm sure someone has written a driver for linux for one - I'll have to have a look.

My Sopranos are at least 640x480 and I've never seen a frame dropped. The lip-sync can wander from time to time but that could well have been a problem at encoding time.

I'm using reasonably good quality sony headphones but perhaps I should plug it into my hifi for a true opinion of the sound. The audio hardware may have been compromised for their TV-out white elephant or to make room for the loudspeakers.

I've never managed to get the GP2X to do anything that remotely affected its reposne time and that includes fastforwarding and rewinding through big videos.

I've had bad experiences of those tape adaptors before so that could be your weak link. Those volvos do have an excellent stereo though and if you want to get into car hifi in a big way then I've heard they are a good platform for an expensive system because they are built so solidly and don't rattle with big subs.

I think that the compression that mp3 uses also causes some attenuation of certain frequencies that the algorithm considers are inaudible. This might explain the noise artifacts that are audible on very high and very low notes such as I'm hearing on the GP2X. I'd have to plug it into my hifi to be sure that the problem is not with the headphones.

I think you'll find that the term 'compression' in this case referred to "audio compression" - certainly in the context of a comparison with 'attenuation'.

Audio compression is quite different to the compression of digital data such as mp3 (or zip, jpeg etc) uses - it refers to reducing the dynamic range of a signal; i.e. the range between the loudest and softest sounds in a piece of music etc.

Attenuation is simply reducing the level of a signal.

You could, for example, 'compress' a signal so that the softer volume levels are actually increased towards the loudest, whilst leaving the loudest unchanged. In this case, there would be no attenuation at all.

Regards,

--
Mark McDougall, Engineer
Virtual Logic Pty Ltd, 
21-25 King St, Rockdale, 2216
Ph: +612-9599-3255 Fax: +612-9599-3266