Hi, I just wanted to tell you, this video has probably saved the life of my family's old Acorn computer. We have one much like this (though it's a newer model), and didn't know that there was a risk of this battery leak and corrosion happening. I came across this video a few days ago by chance, saw what happened here, and immediately thought 'this is probably happening to ours'. I got it out of the attic and opened it, the battery had started to leak but not much, according to my computer tech friend I got to it just in time. So I've removed the battery and cleaned it with acetone and toothbrushes (according to the instructions of my friend) and it still works. Anyway, thanks. Great video by the way.
+dusthillguy If they aren't stored right after a few years you get general corrosion over the PCB in general - my A3010 was left in the attic in less than ideal conditions and went that way :(
I've had to repair a few machines by "reconstructing" such traces with wire-wrap wire and conductive ink pens. I am not always successful and it often requires days with a schematic, an ohm meter and a notebook - checking continuity and figuring out which traces have vanished. It is indeed a chore but not entirely impossible.
Econet was a network interface. This allowed the rather unique ability to link many Archimedes together to transfer files between machines. When Bill Gates visited Acorn to try to sell his MSBASIC Acorn were rather amused to see how primitive it was compared to BBC-BASIC. When we showed him the Econet system, he literally asked what was 'networking'. Hehe. He didn't sell us anything.
There were a lot of BASIC's far advanced to MSBASIC, but it was more widespread. BASIC-09 and Sinclair QL BASIC were two of my favorites. Sadly, I never owned any of the BBC or Acorn micro's - my broke arse merely drooled at anything I could find on them. The thing about MSBASIC is that it was conceived on the 8080A and when even ported to other more advanced CPU's, it's operation was kept as close as possible so programs from one computer, allowing modifications for differences in display, generally worked. I suppose that is why it was so popular... along with the fact that MITS sold it for the Altair...
@@BobsBand Have you even seen or tried the early MS Basics from the eignties? Have you seen or used BBC Basic from the same era? The comparison was night and day. I know some people think Bill Gates is a god who invented everything and made the best of everything... but I'm afraid it isn't true. He didn't even write MS DOS, it was an existing product that he licenced and renamed. 🙄
Don't forget Econet dated further back than the Archimedes - it was available on the BBC Model B Model A machines back in '84, then the Master series, then the Archimedes.
A 50/50 mix of white vinegar and water will remove the corrosive material from the battery (which is alkaline). Usually I'd just dip and old toothbrush in the solution and then lightly scrub the affected area.
Its not the first ARM Processor computer. The ARM2 was also in the Acorn A305/310, A410/A440 and A510/540s which pre dated it by a year or two. I have an A3000 and its what I learnt to program ARM assembler on back in 1989...
+Melanie Rhianna The A3000 was IMO the first all around matured ARM system at the time though - I had the 3010 which was a bit more refined again - the older Archimedes 400-500 systems were a lot more rudimentary heh.
An interesting piece of trivia about the first ARM prototype from back in 1983: Steve Furber, one of the creators, went to test how much power it drew one day during the prototype phase, connected a multimeter to the power supply and turned it on and started executing some code on the ARM1. The multimeter read 0. He had actually forgotten to plug in the PSU to begin with. The ARM1 was so power efficient, it was being powered by the board's capacitors as they slowly discharged. Yet it was still 4x as powerful as a VAX 11/780, the most popular minicomputer of the time. What an absolutely genius CPU design. I'm posting this comment from my Raspberry Pi 4, powered by the great-great-great-great-great-great-great-great-great-great grandson of the ARM1.
The ARM (1) was used in a coprocessor the for BBC B, B+ and Master series computers along with the Archimedes 305 and 310, the ARM2 was used on the A400 series and A3000, ARM250 for the A3010 and A3020, ARM3 (upgrade on A400 series) standard in the A5000 before they moved to the ARM610 and 710 for the RiscPC. ARM (company was founded by Acorn, Apple and VLSI to design these future chips). ECONET was an Acorn proprietary network solution for connecting these machines to a local network (including file and print servers)
In some ways ECONET was a fairly advanced LAN protocol. With an 8 bit station and an 8 bit network addressing scheme. It had the variation of Acorn Universal Networking (AUN) which encapsulated an ECONET frams in a UDP/IP datagram.
The ARM 1 was only ever used in development boards, the A3xx, A4xx, A4xx/1, A3000 and the R140 all used the ARM 2. The A540, A5000, A4 (laptop), R225 and R260 all used the ARM 3. The A3010, A3020 and A4000 all used an ARM250 which was an ARM 2 core and MEMC1a, graphics and I/O in a single package (aka, what we call a SoC today.) See: www.heyrick.co.uk/assembler/proctype.html and en.wikipedia.org/wiki/Acorn_Archimedes
The OS has been upgraded on this. The A3000 came with RISC OS v2. OS v3 was an optional upgrade. Econet was an old networking scheme originally used on the old BBC micro computers. It worked very much like 10-base-2 ethernet, but at a much lower bit rate - 1Mbps I think. Arabella is the graphics output chip. Interestingly, there was no ESD protection on the output drivers which were connected directly to the VGA port on the back. Disconnecting or connecting a monitor while power was on was near guaranteed to blow the chip. Replacement of the arabella was a very common repair.
Yes, I had this A3000 after selling upgraded BBC Model A, then I moved on to Risc-PC which help my OU project T401 as a speech recognition project with my first C programming. It was well ahead from IBM heyday (AT and XT with 186/286/386/486). The graphic was fast and smooth thanks to the efficient ARM MCU. To honor them, my nickname became Riscy which most workplaces adopted my name. It very sad I had to sell them because lack of software for engineering work and went to IBM clone under Window 98. I still have BBC Master up in the loft somewhere.
**sigh** leaky batteries.. probably the most common cause of death for otherwise perfectly intact vintage electronics.. I've just invested a whole weekend into restoring a 1990 DSO (Gould 400) where the calibration data battery had eaten away a part of the control board. Thankfully, the important ADC board was unharmed.
I remember seeing a game called Zarch / Lander on one of these things in my secondary school, - a game written by Dave Braben (better known for Elite) - 3D FILLED polygon graphics, truly impressive at the time.
I designed the first ever 4MByte memory upgrade board for the A3000 - it was never actually designed to take 4M & at the time Acorn said it wasn't possible!
I recently got one of these. I found it when I was clearing out my dad's old house, he had it stashed in a cupboard that time forgot. I haven't had the chance to take it apart though and now thanks to you I don't have to. Cheers!
Years old, but... Traditionally, Acorn mice plugged into the keyboard, which in turn then plugged into the PC box. That meant that mouse cables were very short. The mouse socket was on the bottom of the machine so it was the same place in relation to the keyboard as for keyboards on the separate box units like the A310.
Hey Dave, how about a bit of fabrication instead of refurbishment ? what I mean is, a)check how far that corrosion has gone b)find a nice place at the pcb were you can literally saw it c)make your own pcb according to the schematics d)solder the parts on new pcb e)connect your pcb to the main pcb ...Hope it work.
That's the main reason, why i removed the batteries from my 486 mainboard. I soldered a wire to the pins the batteries were connected to before and used the wire to get some distance between the mainboard and the batteries. Now if the batteries will leak, they won't harm the mainboard.
OpenGL4ever they should run suff like these coincell batterys and such away from the main board with some wire and put them in ther own isolated box away from the main board.
tbbw Today they use those coincell size lithium batteries, they don't leak. But they didn't used them in the past. In the past they used NiCd and they do definitely leak.
OpenGL4ever yeah i guess your right but still a good practice :P Still wonder if the coincells leek abit after 20 or so years from now... most alcaline batterys seem to want to do that if ther left discharged for too long.
Ah I remember using BBCs and Acorns back in my primary school days back in the UK. Amazing video, thanks. I also love how very quaint and British the hand-painted power warning sign is!
The capslock-ctrl swap is to appeal to unix (specifically emacs) users. "Unix" Layout Sun keyboards and the Commodore Amiga have Ctrl next to 'A' too. Though the Sun "Unix" layout also swaps '~' and ESC, to appeal to vi users. There also appears to be an additional pound-sterling key and an additional key on the numeric keypad like the Macintosh and Amiga, though the Amiga has no numlock, and instead has parenthesis, making it useful for writing formulas and lisp.
No - MEMC1 always supported supported 4M (The A440 preceded the A3000) . You could use two of the later MEMC1a chips for 8M (I did a retrofit board for the 440 to do this). Acorn deliberately crippled the A3000's memory decode logic to prevent >2M to avoid affecting sales of more expensive machines. ISTR they actually added hardware in the memory decoding to do this, but either cocked it up or the engineers "accidentally" made it possible.
I still have my BBC model B from 1986, 5 1/4 inch floppy drive, 6502 second processor, and a pair of analogue joysticks.. and it all still works! Back in the day you could also buy a BBC B in kit form and solder it together yourself. I also have in working condition an Amiga 500, Amiga 1200 and an Atari 512ST in my 'retro' collection.
We had BBC B's at Primary school, then A3000s and A4000s at secondary school. Great machines. In my 2nd to last year at school they were all thrown out and replaced with Windows 3.1 machines. It was a shame because they wouldn't even sell the old Acorns to us pupils, they were just binned.
Yaaaayyy. I had them at my secondary school, computer studies, playing this game, a triangular aircraft flying through space. I can't remember the name of the game, but this was late 80's - early 90's. Great to see one again.
Econet was Acorn's own network hardware I believe...We used to send rude messages to other computers in the class then pull the Econet plug so they wouldn't hear the notification sound when they sent one back trying to find out who it was. =)
I know I'm commenting on a very old video, but: These were shipped with an RISCOS2.x and the OS3 chips were shipped to end users for them to upgrade the OS. I dont recall if this was a free upgrade or something you needed to pay for, but certainly the end-user would open the machine and replace the chips in order to upgrade the OS.
I used to program the Archimedes machine code and before that the Beeb 128K , Model B , Acorn Atom. True british innovation. ARM tech great share to buy if you want to make some money in the future especially if this big server deal comes off.
The A3000, like the A400 series and later A300 series, shipped with RISC OS 2 (which weighed in at 512K). (The early A300s shipped with Arthur, a rather unfinished OS.) By replacing the ROM chips, which is what has happened to yours, the machines could be upgraded to RISC OS 3, and weighed in at 2MB.
Bear in mind that the OE and CS pins on a mask ROM are programmable, same as the data image. This was a trick to save gates in the address decoding, so that two chips could share one select/address line and decode the selection of one from the other by the internally-unique active state of the CS pin. Persuading a device programmer to read one of these can be a problem when the UV part has an active-low pin, and your mask-programmed part expects a logic high to become active. Best of luck.
I agree -- far from hopeless!! It wouldn't even be that much work -- you could do a small series (one or two videos) of the repair!! I find it MUCH more satisfying to fix things like this and have them boot and work at the end than just replacing a cap or two. As you said, give it another good scrub with the Electrolube IPA or something similar, get some anti-corrosion on there, and just use thin wire to jump broken traces... replace all the off-the-shelf parts on top and away you go!
Lots of ARM videos in my recommendations these days. Just in case it hasn't been said (it's certainly not in the video title): this is NOT the first ARM based computer, and not the first ARM chip. That was the BBC ARM 2nd Processor in 1986, using the ARM 1. After that we got the A-310/305/410/340 and R-140 models. Only after Two revisions of Arthur (the initial OS) and RISC OS (its replecament OS) did they launch the A-3000. I.e. it's the 7th commercially available ARM based computer, 3 years after the first one.
Ah, that's a bummer man. I'm guessing no further progress was made? As for micro men... bloody love that dramatisation. Slightly addicted to it I think. Great stuff
I had one of these when I was a kid, we had them in school as well. It was much faster than my Amiga 500+. Very good machine at the time. I remember playing PAC-mania and lemmings on it. It always looked and sounded better than the Amiga versions.
When you put back a battery, I advise you to connect wires to the optional battery connector, and put the battery in the battery holder near the mouse connector. You'll have to use metallic bits as found in remote controlers to make contact on each extremity. Hope this helps.
Thanks Dave, I was looking forward to this vintage computer teardown & repair (this is right up my street) but my heart sank as soon as I saw the battery corrosion mess. This would be an interesting repair to follow through if you wanted to do it, but with corroded traces it would be time-consuming and a PITA to fix. The worst battery corrosion mess I ever faced was with an Apple Mac SE/30... it looked like a bomb had gone off inside the computer... lithium battery gunk & corrosion everywhere.
In 1992, Acorn released RISC OS 3 as an upgrade for earlier machines- the A3000 would have shipped with RISC OS 2. The reason your machine isn't booting is probably that the CMOS isn't coming up.
Nice vid. The ROMs are an upgrade, it originally shipped with RISC OS 2. Arrabella is the VIDC chip providing video and sound. There are plenty of A3000 battery repair resources and manuals etc. on my site too.
Hello ! This Risc Computer is history. In 2012 a ARM machine computer with 1.7 GHz Exynos 5000 Series processor manufactured by Samsung, in 2013 a ARM machine with 1.7GHz dual-core Exynos 5250 GAIA processor manufactured by HP, and soon the ARM 64 bits servers ... the future !? Best regards !
The Arm 1 was missing the multiply instruction. The thoughts were to use the barrel shifter et cetera to create a multiply in software however to compete in benchmarks it was decided that they would create it in hardware for the arm 2. This took a significant amount of the 30,000+ transistors of the entire processor. The later Arm 250 was one of the first system on chip. Integrating memory controller, video and other chips.
Fixing it with mod wires not only would be a lot of work, it would leave you feeling really unimpressed with your work. You could try cutting out that whole section, and replacing it with your own fabricated version of the part of you board you removed.
The battery leakage is a classic damage of old computers. The damage is always deep and the repair is cost prohibited. Except the case of very rare and precious electronics.
if its so common why dont they come up with a better design? maybe put the battery under the board, at least in terms of gravity it should mean less leakage directly on the board.
Ahh, the good old Acorn Archimedes! I believe they originally shipped with Arthur then Risc OS 2, then Risc OS 3, Econet was the network port that Acorn used, we used the A3010 and later the A3020 in schools here in the UK, and the A4000 / A5000 "server" lol, outstanding GUI capability for it's day mind you! More educational than personal computer then came the Risc PC with a 486SX backplane module and !PCEm. It's a shame Acorn died out, I believe Pace took part of them over for set top boxes
Hey Dave, just watched the TRS-80 teardown video before this one, they had a ribbon cable hanging from a single socket expanding the rom bus and left the rest depopulated. I bet you could get the ARM up and booting by fixing the rom1 points, pulling the CE lines from the rom2, 3, and 4 sockets with a bit of bodge-wire off to a row of five sockets on a PCB, with the "3rd socket" over the rom1 points with standard header... Two chips above, two chips below (to fit under the keyboard slope).
HI dave i had the same problem a few years ago with a corroded board much worse than yours. i used very fine steel wire to clean and remove solder mask etc down to bare copper then masked everything up then applied conductive paint where traces should be it took a while but i got it working and still going strong today.
the A3000 was the only archimedies in that form factor (which is reminiscent of the BBC micro). Earlier archimedies and all high end ones were of the seperate main unit and keyboard style and the successors to the A3000 were in a case with integrated keyboard like the A3000 but with less depth. I suspect the reason for the mouse port being on the bottom was to put it close to the keyboard stuff. Archimedies with seperate keyboards had the mouse connected to the keyboard.
A bunch of us Uni students in 1988 played with the A305 ! . we developed a graphical development tool with drag and drop components in C++ .. 10+ years before Visual Basic and Delphi! too bad we didn't market it cos we all went and got real jobs after Uni ! :-) that Arm Machine code Assembler instruction set was amazingly simple. (ahhh.. good times)
RISC OS is available for the Raspberry Pi, specifically RISC OS 5, which is an open source branch, a direct descendant, of the original RISC OS 2 (or 3, in this case, it's been upgraded at some point). There's a downside however, 26bit ARM software doesn't run properly/at all on the Pi's 32bit CPU. This can be solved by using Aemulor, or less cleanly with ArcEm, though you'll need ROM dumps to make ArcEm work. Still, the OS itself runs great as-is, worth a go if you'd like to play with RISC OS.
You basically just have to bridge the gap where the break is, which you can do several ways, either with conductive paint or wire. You can either lightly sand off the solder mask and solder from one side of the break to the other, or you can find other pads on the board which connect to either end of the trace and jump the gap with a wire.
Excellent Video. A bit to modern for my tastes, but still it's entertaining... My grandfather used to make us games on his Texas Instruments TRS 180, and would store them on cassette tape drives. After ww2, he assisted in developing voice of America and spent his retirement with his grand kids... Smartest man I ever knew.
I remember when they got these in our high school, back in about 1988-89 ish. Was meant to be the gruntiest thing out back then. Was one of the first "Computer studies" classes at our school....we had to use basic and make programs/games etc. Ah those were the shit old days. haha.
I always loved my Acorns. Had two BBC's from 1983. And later an A300 in 1987 and one in 1989. The last one had a 'job' to do. It was powered on for 4 hours every evening, booted from a floppy drive and did so until I stopped it ... 20 years later. No kidding ... It ran for 20 years ... from a floppy ... Can't see any modern machine do that .... Oh, btw ... it was a Bingo computer in a cafe close by. Running a program that I wrote for the place. Great fun.
Battery corrosion is best removed by rinsing under running water to dissolve the salts, then an alcohol rinse to remove the water. IPA won't remove all the corrosive chemicals lingering around.
All production A series and Risc PC machines used a quadrature mouse with a 9 pin mini DIN connector. The A500 Archimedes prototype used a very strange mouse. You're quite right to remember that the mouse port moved to the rear on the A3010 and A3020.
I was really getting in to that, shame you couldn't get it working. Here in the UK we used to use these (when they let us) at primary school in the late 80's, they were pretty expensive though, whilst virtually every class had a BBC micro A or B the entire school only had one Acorn and back then they had to bring in specialist teachers to do anything worthwhile with any of the computers as very few teachers knew anything about IT. it wasn't even an option for lessons in secondary school in the mid-90's!
I'm guessing the mouse port was underneath so it could be kept from being stolen in classrooms, wouldn't be at all surprised is a screw was available to keep it in place. I'm still using a Acorn BBC Master 128 :-)
Had one or two of these at school when I was a kid. It was supposedly 'good for graphics'. I don't remember it being used for anything other than drawing with it's paint program. Thanks for the video Dave.
The vents are because the Acorn made BBC Master was well known for cooking its guts, and even catching fire. My old high school had shedloads of these in the UK
If all else fails, how about using the keyboard and the case, with a Raspberry Pi running an emulator of the Acorn? Perhaps even finding a case compatible serial keyboard, and swapping out key-caps? You could call it an Acorn Pi.
The MEMC1's handling of greater than 2M left a lot to be desired- there was bog all drive capability on the lines, which made handling more than a couple of extra DRAMs a real problem. MEMC1a improved this, and made the cascaded MEMC feature actually work (it was always supposed to be present, but didn't work in MEMC1, and even on MEMC1a really required a matched pair of MEMCs.)
Hi Dave... I think you should use it to do a tutorial video for corrosion damage repair for people that would either want or need to know how to do it for purposes of restoring vintage electronics or repair something that suffered that type of damage. either way I think it would make a great tutorial video for those who want to know. have a great day and... Cheers from a random subscriber from Canada.
I remember repairing AT 286 mother boards back in the mid 90's were the lithium battery always leaked and the tracks were damaged, during those days, im using baking soda mixed with small qtty of hot water to stop the chemical reactions before cleaning the board with ethanol and repairing the pcb tracks, for the battery im using 2 AA batteries housed in a battery case installed away from the boards, good video, we will wait for the repair video...
I had a similar fault on my 1979 Intertec Superbrain. The compound between the picture tube and the surface glass broke down and dropped into the RAM. Caused corrosion and shorts. I had to remove all the DRAM chips and put them into new sockets - It was a lot of work to fix that, but it was worth the effort.
Been ( was :-) ) in the industry 30 years and didn't know ARM came out of Acorn! Also just finished watching 'The Micro Men' and it was good--didn't know anything about the relationships between Sinclair/Acorn/BBC. Thanks Dave!
Nice find Dace, The A3020 was one of the first machines I used. They blew contemporary IBM clones out of the water at the time. Its quite disappointing they don't get more notice in the history of personal computing. It would be really nice to see you get it or a different Acorn of a similar vintage up and running.
Battery leakage is a problem in some Atari systems as well as Amiga systems that have the onboard battery backup. I bought an Amiga A500 at a market stall sale and later found out about the battery issue and was relieved to find that my Amiga (very early one) never had battery backup. As for the names of the chips, Anna was the memory chip controller, Arbarella is the VIC graphics chip... you can find out the chip detail by searching on-line. I understand the naming of the chips was down to the developer naming their chips after the girls they dated or were dating at the time. Anna MUST have been VERY MEMORABLE *nudge nudge wink wink*and Arabella must have been visually stunning..!
This type of damage is very common on Acorns, but can normally be repaired if you have the time to check all the tracks. Hope it didn't go in the bin! You can replace the battery with 2 AAs (as the battery holder beneath was originally intended for).
An old style EPROM is not the only option in order to replace a mask ROM. You could use NOR-Flash. I'm pretty sure they are still available in DIL-packages, such as the 290XX-series.
The Acronym 'Acorn RISC Machine' (in use since 1983) was changed to 'Advanced RISC Machine' in 1990 when Acorn and others formed the spin-off company Advanced RISC Machines Ltd (which became ARM Ltd in 1998)
Bummer. Corrosion sucks. I can totally understand why you put this project aside. I'd still love to see it running again if you find time to fiddle with it. I love old tech.
Interestingly it has the numlock key even though there would be no need for it. The cursor keys are not even printed in the numpad but they are there for old PC users. Those who do not know original IBM PC had no separate cursor keys, they were in the numpad and numlock changed the functionality. After the cursor keys were added they could have dedicated the numpad to just numbers but for compatibility they kept the numlock functionality.
Hi, I just wanted to tell you, this video has probably saved the life of my family's old Acorn computer. We have one much like this (though it's a newer model), and didn't know that there was a risk of this battery leak and corrosion happening.
I came across this video a few days ago by chance, saw what happened here, and immediately thought 'this is probably happening to ours'. I got it out of the attic and opened it, the battery had started to leak but not much, according to my computer tech friend I got to it just in time. So I've removed the battery and cleaned it with acetone and toothbrushes (according to the instructions of my friend) and it still works.
Anyway, thanks. Great video by the way.
+dusthillguy If they aren't stored right after a few years you get general corrosion over the PCB in general - my A3010 was left in the attic in less than ideal conditions and went that way :(
I've had to repair a few machines by "reconstructing" such traces with wire-wrap wire and conductive ink pens. I am not always successful and it often requires days with a schematic, an ohm meter and a notebook - checking continuity and figuring out which traces have vanished. It is indeed a chore but not entirely impossible.
Good job but be carefull with acetone, ive melted a few cases in my time, prefer isopropyl alc
the mother of all modern based ARM technology deserves to be preserved!
The Acorn Archimedes machines were beautiful machines with an advanced operating system. I loved them.
Econet was a network interface. This allowed the rather unique ability to link many Archimedes together to transfer files between machines.
When Bill Gates visited Acorn to try to sell his MSBASIC Acorn were rather amused to see how primitive it was compared to BBC-BASIC. When we showed him the Econet system, he literally asked what was 'networking'. Hehe. He didn't sell us anything.
Yeah right.
There were a lot of BASIC's far advanced to MSBASIC, but it was more widespread. BASIC-09 and Sinclair QL BASIC were two of my favorites. Sadly, I never owned any of the BBC or Acorn micro's - my broke arse merely drooled at anything I could find on them. The thing about MSBASIC is that it was conceived on the 8080A and when even ported to other more advanced CPU's, it's operation was kept as close as possible so programs from one computer, allowing modifications for differences in display, generally worked. I suppose that is why it was so popular... along with the fact that MITS sold it for the Altair...
@@BobsBand Have you even seen or tried the early MS Basics from the eignties? Have you seen or used BBC Basic from the same era? The comparison was night and day. I know some people think Bill Gates is a god who invented everything and made the best of everything... but I'm afraid it isn't true. He didn't even write MS DOS, it was an existing product that he licenced and renamed. 🙄
Don't forget Econet dated further back than the Archimedes - it was available on the BBC Model B Model A machines back in '84, then the Master series, then the Archimedes.
@@crashoverride328 It was even available on the Atom - Acid Burn...
A 50/50 mix of white vinegar and water will remove the corrosive material from the battery (which is alkaline). Usually I'd just dip and old toothbrush in the solution and then lightly scrub the affected area.
Its not the first ARM Processor computer. The ARM2 was also in the Acorn A305/310, A410/A440 and A510/540s which pre dated it by a year or two. I have an A3000 and its what I learnt to program ARM assembler on back in 1989...
Melanie Rhianna lol and what if I am?
+Joseph Beasley You're so funny. You wouldn't have a chance. I'd break you like a twig.
+Melanie Rhianna hahahahahaha hahahahahaha haha bullshit
+Stabby666 Don't feed the troll.
+Melanie Rhianna The A3000 was IMO the first all around matured ARM system at the time though - I had the 3010 which was a bit more refined again - the older Archimedes 400-500 systems were a lot more rudimentary heh.
An interesting piece of trivia about the first ARM prototype from back in 1983: Steve Furber, one of the creators, went to test how much power it drew one day during the prototype phase, connected a multimeter to the power supply and turned it on and started executing some code on the ARM1. The multimeter read 0. He had actually forgotten to plug in the PSU to begin with. The ARM1 was so power efficient, it was being powered by the board's capacitors as they slowly discharged. Yet it was still 4x as powerful as a VAX 11/780, the most popular minicomputer of the time.
What an absolutely genius CPU design. I'm posting this comment from my Raspberry Pi 4, powered by the great-great-great-great-great-great-great-great-great-great grandson of the ARM1.
Also the old leaky battery issue was a problem on lots of computers back then. Its a standard job on various machines.
The ARM (1) was used in a coprocessor the for BBC B, B+ and Master series computers along with the Archimedes 305 and 310, the ARM2 was used on the A400 series and A3000, ARM250 for the A3010 and A3020, ARM3 (upgrade on A400 series) standard in the A5000 before they moved to the ARM610 and 710 for the RiscPC. ARM (company was founded by Acorn, Apple and VLSI to design these future chips). ECONET was an Acorn proprietary network solution for connecting these machines to a local network (including file and print servers)
The standard CPU in the Model B and B+ was a 6502. Acorn later released an ARM dev kit that connected to the machine using the Tube interface.
In some ways ECONET was a fairly advanced LAN protocol. With an 8 bit station and an 8 bit network addressing scheme. It had the variation of Acorn Universal Networking (AUN) which encapsulated an ECONET frams in a UDP/IP datagram.
The ARM 1 was only ever used in development boards, the A3xx, A4xx, A4xx/1, A3000 and the R140 all used the ARM 2. The A540, A5000, A4 (laptop), R225 and R260 all used the ARM 3. The A3010, A3020 and A4000 all used an ARM250 which was an ARM 2 core and MEMC1a, graphics and I/O in a single package (aka, what we call a SoC today.) See: www.heyrick.co.uk/assembler/proctype.html and en.wikipedia.org/wiki/Acorn_Archimedes
The OS has been upgraded on this. The A3000 came with RISC OS v2. OS v3 was an optional upgrade.
Econet was an old networking scheme originally used on the old BBC micro computers. It worked very much like 10-base-2 ethernet, but at a much lower bit rate - 1Mbps I think.
Arabella is the graphics output chip. Interestingly, there was no ESD protection on the output drivers which were connected directly to the VGA port on the back. Disconnecting or connecting a monitor while power was on was near guaranteed to blow the chip. Replacement of the arabella was a very common repair.
Yes, I had this A3000 after selling upgraded BBC Model A, then I moved on to Risc-PC which help my OU project T401 as a speech recognition project with my first C programming. It was well ahead from IBM heyday (AT and XT with 186/286/386/486). The graphic was fast and smooth thanks to the efficient ARM MCU. To honor them, my nickname became Riscy which most workplaces adopted my name. It very sad I had to sell them because lack of software for engineering work and went to IBM clone under Window 98. I still have BBC Master up in the loft somewhere.
**sigh** leaky batteries.. probably the most common cause of death for otherwise perfectly intact vintage electronics..
I've just invested a whole weekend into restoring a 1990 DSO (Gould 400) where the calibration data battery had eaten away a part of the control board. Thankfully, the important ADC board was unharmed.
I remember seeing a game called Zarch / Lander on one of these things in my secondary school, - a game written by Dave Braben (better known for Elite) - 3D FILLED polygon graphics, truly impressive at the time.
Zarch was one of the launch titles for the Archimedes (the earlier A3xx/A4xx series iIrc).
I remember using those dazzling Acorn PCs when I was in primary school in the UK back in the late 1990s.
You mean acron had the control key in the correct place IBM had it in the wrong place :)
I designed the first ever 4MByte memory upgrade board for the A3000 - it was never actually designed to take 4M & at the time Acorn said it wasn't possible!
I recently got one of these. I found it when I was clearing out my dad's old house, he had it stashed in a cupboard that time forgot. I haven't had the chance to take it apart though and now thanks to you I don't have to. Cheers!
Years old, but...
Traditionally, Acorn mice plugged into the keyboard, which in turn then plugged into the PC box. That meant that mouse cables were very short. The mouse socket was on the bottom of the machine so it was the same place in relation to the keyboard as for keyboards on the separate box units like the A310.
Hey Dave,
how about a bit of fabrication instead of refurbishment ? what I mean is, a)check how far that corrosion has gone b)find a nice place at the pcb were you can literally saw it c)make your own pcb according to the schematics d)solder the parts on new pcb e)connect your pcb to the main pcb ...Hope it work.
+Ellinon Enosis That's a multi-layer (4, specifically) PCB, you'd never be able to recreate it like that.
Those leaking internal batteries make me sad. :-(
That's the main reason, why i removed the batteries from my 486 mainboard.
I soldered a wire to the pins the batteries were connected to before and used the wire to get some distance between the mainboard and the batteries.
Now if the batteries will leak, they won't harm the mainboard.
OpenGL4ever they should run suff like these coincell batterys and such away from the main board with some wire and put them in ther own isolated box away from the main board.
tbbw Today they use those coincell size lithium batteries, they don't leak. But they didn't used them in the past. In the past they used NiCd and they do definitely leak.
OpenGL4ever yeah i guess your right but still a good practice :P
Still wonder if the coincells leek abit after 20 or so years from now... most alcaline batterys seem to want to do that if ther left discharged for too long.
Ah I remember using BBCs and Acorns back in my primary school days back in the UK. Amazing video, thanks. I also love how very quaint and British the hand-painted power warning sign is!
I lost it when you lost that resistor.
we had one in our classroom, the entire school had to share it, so we used to get about 10mins each every week.
The capslock-ctrl swap is to appeal to unix (specifically emacs) users. "Unix" Layout Sun keyboards and the Commodore Amiga have Ctrl next to 'A' too. Though the Sun "Unix" layout also swaps '~' and ESC, to appeal to vi users. There also appears to be an additional pound-sterling key and an additional key on the numeric keypad like the Macintosh and Amiga, though the Amiga has no numlock, and instead has parenthesis, making it useful for writing formulas and lisp.
I used one of these machines in college, to do PCB design on, in the early 90's. Good days :)
fantastic. Thanks for sharing the video. I'm an electronics tech, computer hobbyist/programmer and lover of retro. This stuff is right up my alley
No - MEMC1 always supported supported 4M (The A440 preceded the A3000) . You could use two of the later MEMC1a chips for 8M (I did a retrofit board for the 440 to do this).
Acorn deliberately crippled the A3000's memory decode logic to prevent >2M to avoid affecting sales of more expensive machines.
ISTR they actually added hardware in the memory decoding to do this, but either cocked it up or the engineers "accidentally" made it possible.
I still have my BBC model B from 1986, 5 1/4 inch floppy drive, 6502 second processor, and a pair of analogue joysticks.. and it all still works! Back in the day you could also buy a BBC B in kit form and solder it together yourself.
I also have in working condition an Amiga 500, Amiga 1200 and an Atari 512ST in my 'retro' collection.
We had BBC B's at Primary school, then A3000s and A4000s at secondary school. Great machines. In my 2nd to last year at school they were all thrown out and replaced with Windows 3.1 machines. It was a shame because they wouldn't even sell the old Acorns to us pupils, they were just binned.
Yaaaayyy. I had them at my secondary school, computer studies, playing this game, a triangular aircraft flying through space. I can't remember the name of the game, but this was late 80's - early 90's. Great to see one again.
+Mark Bartlett That sounds like 'Lander' - re-released as 'Zarch'. I have an Amiga version.
Oh great. That sounds familiar you know, i think you're right there. Thanks.
+Jack Hughes Thanks. I have Virus and am terrible at it. I love the scrolling landscape.
Or possibly "Elite"?
Econet was Acorn's own network hardware I believe...We used to send rude messages to other computers in the class then pull the Econet plug so they wouldn't hear the notification sound when they sent one back trying to find out who it was. =)
I know I'm commenting on a very old video, but: These were shipped with an RISCOS2.x and the OS3 chips were shipped to end users for them to upgrade the OS. I dont recall if this was a free upgrade or something you needed to pay for, but certainly the end-user would open the machine and replace the chips in order to upgrade the OS.
I used to program the Archimedes machine code and before that the Beeb 128K , Model B , Acorn Atom. True british innovation. ARM tech great share to buy if you want to make some money in the future especially if this big server deal comes off.
sad to see, First computer I had was a VIC20, and after that an Atari 800. Class mchines realy enjoyed the blast from the past.
The A3000, like the A400 series and later A300 series, shipped with RISC OS 2 (which weighed in at 512K). (The early A300s shipped with Arthur, a rather unfinished OS.) By replacing the ROM chips, which is what has happened to yours, the machines could be upgraded to RISC OS 3, and weighed in at 2MB.
Bear in mind that the OE and CS pins on a mask ROM are programmable, same as the data image. This was a trick to save gates in the address decoding, so that two chips could share one select/address line and decode the selection of one from the other by the internally-unique active state of the CS pin.
Persuading a device programmer to read one of these can be a problem when the UV part has an active-low pin, and your mask-programmed part expects a logic high to become active.
Best of luck.
I agree -- far from hopeless!! It wouldn't even be that much work -- you could do a small series (one or two videos) of the repair!! I find it MUCH more satisfying to fix things like this and have them boot and work at the end than just replacing a cap or two.
As you said, give it another good scrub with the Electrolube IPA or something similar, get some anti-corrosion on there, and just use thin wire to jump broken traces... replace all the off-the-shelf parts on top and away you go!
Lots of ARM videos in my recommendations these days. Just in case it hasn't been said (it's certainly not in the video title): this is NOT the first ARM based computer, and not the first ARM chip. That was the BBC ARM 2nd Processor in 1986, using the ARM 1. After that we got the A-310/305/410/340 and R-140 models. Only after Two revisions of Arthur (the initial OS) and RISC OS (its replecament OS) did they launch the A-3000. I.e. it's the 7th commercially available ARM based computer, 3 years after the first one.
Ah, that's a bummer man. I'm guessing no further progress was made? As for micro men... bloody love that dramatisation. Slightly addicted to it I think. Great stuff
Great vid as always Dave, loved this one especially. It was the second computer I learnt on at school (the first being the BBC Micro).
I had one of these when I was a kid, we had them in school as well. It was much faster than my Amiga 500+. Very good machine at the time. I remember playing PAC-mania and lemmings on it. It always looked and sounded better than the Amiga versions.
When you put back a battery, I advise you to connect wires to the optional battery connector, and put the battery in the battery holder near the mouse connector.
You'll have to use metallic bits as found in remote controlers to make contact on each extremity.
Hope this helps.
Thanks Dave, I was looking forward to this vintage computer teardown & repair (this is right up my street) but my heart sank as soon as I saw the battery corrosion mess. This would be an interesting repair to follow through if you wanted to do it, but with corroded traces it would be time-consuming and a PITA to fix.
The worst battery corrosion mess I ever faced was with an Apple Mac SE/30... it looked like a bomb had gone off inside the computer... lithium battery gunk & corrosion everywhere.
In 1992, Acorn released RISC OS 3 as an upgrade for earlier machines- the A3000 would have shipped with RISC OS 2. The reason your machine isn't booting is probably that the CMOS isn't coming up.
Nice vid. The ROMs are an upgrade, it originally shipped with RISC OS 2. Arrabella is the VIDC chip providing video and sound. There are plenty of A3000 battery repair resources and manuals etc. on my site too.
Hello !
This Risc Computer is history.
In 2012 a ARM machine computer with 1.7 GHz Exynos 5000 Series processor manufactured by Samsung, in 2013 a ARM machine with 1.7GHz dual-core Exynos 5250 GAIA processor manufactured by HP, and soon the ARM 64 bits servers ... the future !?
Best regards !
The Arm 1 was missing the multiply instruction. The thoughts were to use the barrel shifter et cetera to create a multiply in software however to compete in benchmarks it was decided that they would create it in hardware for the arm 2. This took a significant amount of the 30,000+ transistors of the entire processor. The later Arm 250 was one of the first system on chip. Integrating memory controller, video and other chips.
Fixing it with mod wires not only would be a lot of work, it would leave you feeling really unimpressed with your work. You could try cutting out that whole section, and replacing it with your own fabricated version of the part of you board you removed.
The battery leakage is a classic damage of old computers. The damage is always deep and the repair is cost prohibited. Except the case of very rare and precious electronics.
if its so common why dont they come up with a better design? maybe put the battery under the board, at least in terms of gravity it should mean less leakage directly on the board.
Ahh, the good old Acorn Archimedes! I believe they originally shipped with Arthur then Risc OS 2, then Risc OS 3, Econet was the network port that Acorn used, we used the A3010 and later the A3020 in schools here in the UK, and the A4000 / A5000 "server" lol, outstanding GUI capability for it's day mind you! More educational than personal computer then came the Risc PC with a 486SX backplane module and !PCEm. It's a shame Acorn died out, I believe Pace took part of them over for set top boxes
The A3000 came with Risc OS 2, I think. The Risc OS 3 ROMs are almost certainly after-market upgrades.
thank you for recommending the micro men, awesome film!
Hey Dave, just watched the TRS-80 teardown video before this one, they had a ribbon cable hanging from a single socket expanding the rom bus and left the rest depopulated. I bet you could get the ARM up and booting by fixing the rom1 points, pulling the CE lines from the rom2, 3, and 4 sockets with a bit of bodge-wire off to a row of five sockets on a PCB, with the "3rd socket" over the rom1 points with standard header... Two chips above, two chips below (to fit under the keyboard slope).
I had one of these machines. It was fabulous!
HI dave i had the same problem a few years ago with a corroded board much worse than yours. i used very fine steel wire to clean and remove solder mask etc down to bare copper then masked everything up then applied conductive paint where traces should be it took a while but i got it working and still going strong today.
the A3000 was the only archimedies in that form factor (which is reminiscent of the BBC micro). Earlier archimedies and all high end ones were of the seperate main unit and keyboard style and the successors to the A3000 were in a case with integrated keyboard like the A3000 but with less depth.
I suspect the reason for the mouse port being on the bottom was to put it close to the keyboard stuff. Archimedies with seperate keyboards had the mouse connected to the keyboard.
A bunch of us Uni students in 1988 played with the A305 ! . we developed a graphical development tool with drag and drop components in C++ .. 10+ years before Visual Basic and Delphi! too bad we didn't market it cos we all went and got real jobs after Uni ! :-) that Arm Machine code Assembler instruction set was amazingly simple. (ahhh.. good times)
RISC OS is available for the Raspberry Pi, specifically RISC OS 5, which is an open source branch, a direct descendant, of the original RISC OS 2 (or 3, in this case, it's been upgraded at some point).
There's a downside however, 26bit ARM software doesn't run properly/at all on the Pi's 32bit CPU. This can be solved by using Aemulor, or less cleanly with ArcEm, though you'll need ROM dumps to make ArcEm work. Still, the OS itself runs great as-is, worth a go if you'd like to play with RISC OS.
You basically just have to bridge the gap where the break is, which you can do several ways, either with conductive paint or wire. You can either lightly sand off the solder mask and solder from one side of the break to the other, or you can find other pads on the board which connect to either end of the trace and jump the gap with a wire.
I remember those from school! I loved them.
Econet was for LANS, even the Model B had them. RS232 was used for modems.
the effort is the respect from the community, when u repair it and make it a winner ;)
Excellent Video. A bit to modern for my tastes, but still it's entertaining... My grandfather used to make us games on his Texas Instruments TRS 180, and would store them on cassette tape drives. After ww2, he assisted in developing voice of America and spent his retirement with his grand kids... Smartest man I ever knew.
Dave thank you so much! you inspired me to take electronics engineering as my major in college :D keep inspiring us and keep up the enthusiasm.
Why are we complaining about his voice? I think his voice adds to the enjoyment of the video.
I remember when they got these in our high school, back in about 1988-89 ish. Was meant to be the gruntiest thing out back then. Was one of the first "Computer studies" classes at our school....we had to use basic and make programs/games etc. Ah those were the shit old days. haha.
I always loved my Acorns. Had two BBC's from 1983. And later an A300 in 1987 and one in 1989. The last one had a 'job' to do. It was powered on for 4 hours every evening, booted from a floppy drive and did so until I stopped it ... 20 years later. No kidding ... It ran for 20 years ... from a floppy ... Can't see any modern machine do that .... Oh, btw ... it was a Bingo computer in a cafe close by. Running a program that I wrote for the place. Great fun.
Dave I love your repair videos, please do more they are my favorite.
Scott from Birmingham, Michigan
Battery corrosion is best removed by rinsing under running water to dissolve the salts, then an alcohol rinse to remove the water. IPA won't remove all the corrosive chemicals lingering around.
Wow that is really cool! Leaned a lot in this video
All production A series and Risc PC machines used a quadrature mouse with a 9 pin mini DIN connector. The A500 Archimedes prototype used a very strange mouse. You're quite right to remember that the mouse port moved to the rear on the A3010 and A3020.
Swapping the Ctrl and caps lock makes SO MUCH more sense than the way that modern keyboards are laid out.
I was really getting in to that, shame you couldn't get it working.
Here in the UK we used to use these (when they let us) at primary school in the late 80's, they were pretty expensive though, whilst virtually every class had a BBC micro A or B the entire school only had one Acorn and back then they had to bring in specialist teachers to do anything worthwhile with any of the computers as very few teachers knew anything about IT. it wasn't even an option for lessons in secondary school in the mid-90's!
ARM-1 was the first ARM Chip. The Archimedes range used the ARM-2 range.
I'm guessing the mouse port was underneath so it could be kept from being stolen in classrooms, wouldn't be at all surprised is a screw was available to keep it in place. I'm still using a Acorn BBC Master 128 :-)
Had one or two of these at school when I was a kid.
It was supposedly 'good for graphics'.
I don't remember it being used for anything other than drawing with it's paint program.
Thanks for the video Dave.
The vents are because the Acorn made BBC Master was well known for cooking its guts, and even catching fire. My old high school had shedloads of these in the UK
If all else fails, how about using the keyboard and the case, with a Raspberry Pi running an emulator of the Acorn? Perhaps even finding a case compatible serial keyboard, and swapping out key-caps? You could call it an Acorn Pi.
The MEMC1's handling of greater than 2M left a lot to be desired- there was bog all drive capability on the lines, which made handling more than a couple of extra DRAMs a real problem. MEMC1a improved this, and made the cascaded MEMC feature actually work (it was always supposed to be present, but didn't work in MEMC1, and even on MEMC1a really required a matched pair of MEMCs.)
Hi Dave... I think you should use it to do a tutorial video for corrosion damage repair for people that would either want or need to know how to do it for purposes of restoring vintage electronics or repair something that suffered that type of damage. either way I think it would make a great tutorial video for those who want to know. have a great day and...
Cheers from a random subscriber from Canada.
I remember repairing AT 286 mother boards back in the mid 90's were the lithium battery always leaked and the tracks were damaged, during those days, im using baking soda mixed with small qtty of hot water to stop the chemical reactions before cleaning the board with ethanol and repairing the pcb tracks, for the battery im using 2 AA batteries housed in a battery case installed away from the boards, good video, we will wait for the repair video...
I had a similar fault on my 1979 Intertec Superbrain. The compound between the picture tube and the surface glass broke down and dropped into the RAM. Caused corrosion and shorts. I had to remove all the DRAM chips and put them into new sockets - It was a lot of work to fix that, but it was worth the effort.
Been ( was :-) ) in the industry 30 years and didn't know ARM came out of Acorn! Also just finished watching 'The Micro Men' and it was good--didn't know anything about the relationships between Sinclair/Acorn/BBC. Thanks Dave!
i went from bbc micro to this, blew me away at the time, school had a3330, and even a few a4000's, at the time in 1990, one of the best pc's
Nice find Dace, The A3020 was one of the first machines I used. They blew contemporary IBM clones out of the water at the time. Its quite disappointing they don't get more notice in the history of personal computing. It would be really nice to see you get it or a different Acorn of a similar vintage up and running.
So true. When I first heard it, it was very distracting, but several hundred videos later, I don't even notice.
Battery leakage is a problem in some Atari systems as well as Amiga systems that have the onboard battery backup.
I bought an Amiga A500 at a market stall sale and later found out about the battery issue and was relieved to find that my Amiga (very early one) never had battery backup.
As for the names of the chips, Anna was the memory chip controller, Arbarella is the VIC graphics chip... you can find out the chip detail by searching on-line.
I understand the naming of the chips was down to the developer naming their chips after the girls they dated or were dating at the time. Anna MUST have been VERY MEMORABLE *nudge nudge wink wink*and Arabella must have been visually stunning..!
I have an old Texas Instruments TI99/4A with expansion box that would be good for a tear down video.
It was a very straightforward computer for the time.
I was really excited, when you talked about repairing it, but yeah, the damage has been done.
This type of damage is very common on Acorns, but can normally be repaired if you have the time to check all the tracks. Hope it didn't go in the bin! You can replace the battery with 2 AAs (as the battery holder beneath was originally intended for).
Great video. Glad you've given a good history here ! :)
Ahh the memories!
Think I still have one in the loft somewhere.
Crazy Aussie guy.
Love your channel ❤️
I'm bringing the heck out of your stuff.
An old style EPROM is not the only option in order to replace a mask ROM. You could use NOR-Flash. I'm pretty sure they are still available in DIL-packages, such as the 290XX-series.
The Acronym 'Acorn RISC Machine' (in use since 1983) was changed to 'Advanced RISC Machine' in 1990 when Acorn and others formed the spin-off company Advanced RISC Machines Ltd (which became ARM Ltd in 1998)
Wow. Nice job! The patience required to do something like that is beyond my ability to even imagine :-)
Keep those scratches! It's part of the history of the machine!
Repairing that would be epic! Go for it!
Bummer. Corrosion sucks. I can totally understand why you put this project aside. I'd still love to see it running again if you find time to fiddle with it. I love old tech.
Hooray! Vintage Computer Time! I still kind of want one of these to play with... fond memories of primary school IT :-D
Interestingly it has the numlock key even though there would be no need for it. The cursor keys are not even printed in the numpad but they are there for old PC users. Those who do not know original IBM PC had no separate cursor keys, they were in the numpad and numlock changed the functionality. After the cursor keys were added they could have dedicated the numpad to just numbers but for compatibility they kept the numlock functionality.