Amstrad Mega PC / Amstrad Mega PC Plus

Well I'm like 15 games off a full PAL Dreamcast collection and I kept getting sniped on games, dynamite cop particularly, I was fed up haha. Previously in the day I was winning another game, I got sniped, slipped in a high enough bid just in time and then was sniped again -.-.

But back on topic, I watched your videos and I am in love with the mega PC, actually something good from Alan Sugar's company, whod've thought looking at him now, silly bald man with his silly program. Before I was into retro consoles I was a bit of an old PC buff but then I took a bit of a break from it when I electrocuted myself on an AT power supply. The Mega PC is the most beautiful thing I've seen for a while, after the Dreamcast collection, acquiring one will be my main focus even if I have to sell an old mac or something, hell even if I have to sell a kidney.

 

Hahaha - Full PAL collection hey? That's a fair few games! I've tended to shy away from collecting games - there's just far too many. That said, I've focused my collecting around the hardware since they can break and be repaired. I suppose I just like fixing things. I guess I should thank the US seller for the faulty Nomad because now it gives me a chance to repair it.... if only I had my game bit drivers dammit!

Do not sell any LC475s! - They are possibly the best pizza box machine I have ever come across in the world. Many good memories of Munchies and Maniac on those 68LC040 - I don't need no FPU!

 

I'd love to see anyone dare ever attempt full PAL Game Boy.

 

Fair few games indeed (nowhere near as many as the other consoles from that generation though), 216/217 (depending on whether you count sega swirl), it's the only console I have deliberately collected games for, before it was just "horde cool looking cheap stuff".
But I totally know what you mean about fixing things, I have a bunch of generic 90s computers and most of them were given to me because the owners told me "they're broken, you'll never fix them", I took that as a challenge, I was mostly successfull, except for dell ones, with their deceptive proprietary 'ATX' connectors.
I got an Amiga 500 boxed and complete for £3 once and it turned out it was one of those newer ones with the NiCad batteries which has burst like in the amstrad (phew, I was worried I would be veering wildly off topic here ), along with every single capacitor and destroyed more or less everything, like beyond recognition. Unfortunately it was beyond a feasible resurrection (didn't stop me trying to fix it though... for months) and I had to buy a slightly older motherboard to replace it.

I have an LCII but no 475, it was a lucky acquisition from a car boot sale with a huuge stack of games, not had time to try any of them yet though :/

I think the idea of getting a mega PC actually has me more excited than finishing my Dreamcast collection now haha. It's all your fault RetroJunkie

 

"Damn! You will have more Mega PCs than cents if you keep this up hahaha! Kind of wish I was in the UK area since we have pretty much none over here."

"I just had a look at your album too... errr you have to work out macro mode on your camera! There's more blur than [insert something that blurs a lot"


I am still looking for bits to complete the collection such as the original keyboard (probably the hardest part to find) and documentation so Im happy to bid on setups that include bits that I need. I know I can sell my duplicates in the end. Also looking for parts to make it faster, Im going to try and and upgrade mine so that it is a good DOS gaming rig as well as a megadrive - the ultimate games machine! I will see if I can post up a spreadsheet where I have identified where I can upgrade.

Re the camera, Ive always had expensive sony cameras which gave me superb pictures so when my main one got water damaged, i just thought a new cheap sony camera with higher megapixels would suffice....obviously you get what you pay for.

Ive also got a good collection of consoles/computers - my favourite used to be the commodore cdtv which in my opinion is the best looking computer ever and still looks good compared to anything made today (got two of these) - it was the first with a cd rom drive. I also have a NES collection with 300 games and lots of accessories - Im not planning to collect all the games as some of the rarer ones go for thousand of pounds (yes thousands). Obviously my favourite now is the mega pc as it is quite expandable provided you have someone like retro junkie you can follow!

 

Well, let us just say. They were more like "no you can not do that, because of etc." back in the day. And the members are still here, so let us just say. You have proved them wrong in their assumption about it is not possible or feasible for that matter. When it comes to upgrading the machine

 

Yikes! I just looked into that... Err definitely not my cup of tea. That's a truck load of carts!

I hate NiCad batteries so much. And I am definitely not looking forward to replacing the capacitors in my… well everythings before they leak. A friend of mine collects old Macs and I've seen the damage on some of his boards… It's going to be really difficult / impossible for some of those tracks on the PCB to be fixed up.

That's another thing about the Mega PC 486SLC board I noticed, the capacitors appear to be tantalum based instead of electrolytic - especially near the AT power connectors. Sealed as can be thankfully!

Hey don't point the finger at me! The others on this thread are just as much to blame!

A very good idea, more documentation on things that can be done can only better the world of Mega PCs. I'll be putting up dedicated pages eventually on retrojunkie.net. For the mean time there are pictures and blog.

I snapped up a Canon 600D DSLR for taking photos of all my collection - it is a really good camera compared with my old point and shoot IXUS. I've got a tripod on order as well to take videos of disassembling various consoles and modding / repairing them too - definitely worth the cash in my eyes!

No way! That CDTV looks crazy badass! It looks like it is going to go VCR on you with that LED front but then it is all those other things? In one unit?!?
And I think we are all in this together pooling our knowledge, you are just as much to thank for finding that 50MHz boost chip! It's given me some motivation to attempt something… how shall we say… interesting on my 386SX Mega PC motherboard. Will keep everyone posted with the results, but those results will be a month off from now or so.

Ahhh, well we all learn something everyday, looking back I cannot believe my luck with snapping up that 486SLC motherboard. What absolute luck!

As a side note got my TeraDrive up and running today. My step down converter works a charm and weighs a tonne... Dual floppies here I come! Video here and pictures here. Stuck some scans of some flyers that came with it. Sure does feel like a Mega PC... with DUAL FLOPPY DISK DRIVES. Model 2 for life!

 

Nothings impossible, as my extremely bad motherboard I posted pictures to earlier in this thread proves. (in regards to leaking batteries!)

 

Times that by 50 though.... Killer effort to get them all fixed up! A preemptive strike against capacitors is the best solution Too bad I didn't get into the Mega PC buying earlier or there might have been some I could have saved earlier. Oh what a cruel world!

 

Re documentation:

Ive attached the service manual for the Amstrad Mega PC complete with schematics. This may help you/others in fixing the tracks on the 386 motherboard. (Im not sure if you have seen this before).

http://www.fvempel.nl/amstradcg/metia/mega.pdf

I have a spreadsheet on my pendrive but its more notes for me on each of the components and what options they are with lots of questions. I will tidy it up and then post but in the meantime, I may just post a detailed description for information for each component. The first one I will start with is the processor.


Re Camera:
Plan to get another camera soon! Its on my list of things to do.


"No way! That CDTV looks crazy badass! It looks like it is going to go VCR on you with that LED front but then it is all those other things? In one unit?!?"

There are lots of cool upgrades that people have done on the CDTV internally. The peripherals you could buy were amazing, you can get wireless mice, wireless trackballs (got one), wireless controllers (got one) and this is on a computer that came out 20+ years ago and was the first to have a cd rom. Ive got plans but they are on the backburner at the moment....

Its funny you say VCR.....Commodore designed the CDTV to fit in as a home appliance and their marketing focused on selling it as a living room device rather than a computer....


"And I think we are all in this together pooling our knowledge, you are just as much to thank for finding that 50MHz boost chip! It's given me some motivation to attempt something… how shall we say… interesting on my 386SX Mega PC motherboard. Will keep everyone posted with the results, but those results will be a month off from now or so. "

I am really looking forward to seeing what you do with the 386 motherboard. My 2nd mega pc is on the way and Im assumming that it will be standard.


"As a side note got my TeraDrive up and running today. My step down converter works a charm and weighs a tonne... Dual floppies here I come! Video here and pictures here. Stuck some scans of some flyers that came with it. Sure does feel like a Mega PC... with DUAL FLOPPY DISK DRIVES. Model 2 for life!"

Damn you Shane! You are making me spend all my money. I want one now! Im assumming you got this from Japan. Im going to send you a PM now.

Im waiting for a ISA network card that comes with the Windows 3.1 driver so that should be interesting.

 

Mega PC Plus Processor & A Little Background

Right I promised a little overview of the research Ive done so far on each component and how it could be upgraded and maybe a little history. Im writing on the fly so this wont be the best written piece. The first bit will be on the processor which is probably one of the key components that was underspecced and contributed to the Mega PC failing. Im not going to go into history for the other component but this sets the background which I hope people may find interesting:

Background:
What we know is that the Mega PC was first released with a 386 SX 25 processor. At the time the 486 had been released and not too long after the early Pentiums. This meant that at the time of release the Mega PC was already nearly obsolete. At this time the rate at which processors increased in speed was phenomenal. The recommendations from computer magazines/experts was to buy the fastest PC you could afford in order for it to not go obsolete. These conditions and the spec of the machine combined with the high initial price £999 (later reduced )meant it wasnt going to do well!

Amstrad:
To understand Mega PC, we have to to understand Amstrad. Amstrad was once one of most successful computer manufacturing companies in the UK. It was founded by Alan Sugar who made his success in the Hi-Fi market. During the time, Hi-Fis were sold as separates with separate power cables, connectors etc. This made them very expense. Alan Sugar success in the Hi-Fi market was based on looking at components that each separate used and seeing where they could be re-used. He developed an all in one Hi-FI which looked like it was made of individual separats but was actually one unit with one power supply, this blew the competition out of the water as he basically reduced costs significantly and could therefore sell cheaper than the competition. In addition to Alan Sugars vision of achieving low costs, he/Amstrad were very innovative releasing unique products such as the Amstrad Double Decker (a twin VHS recorder allowing you to copy tapes, record one program while watching another etc).

He applied these same principles when he entered the computing market. His engineers studied an IBM PC and concluded that they could produce computer cheaper by re-using components and integrating chips. For example a lot of his computers used one power supply which powered both the computer and monitor. His produced a series of IBM clones cheaper than the competition and became such a market leader that software was labelled IBM/Amstrad compatible.

Amstrads fortunes changed when their computers were fitted with Seagate hard drives that failed and had to be recalled. This combined with increasing competition from other large PC manufacturers resulted in them getting a poor reputation for reliability. Amstrad had other successful computers such as the CPC range but they never fully recovered in the PC market. The CPC range although commonly thought of as a home games computer was also used by businesses hence the availability of a green screen monitor option as well as the full colour screen monitors (business and gaming)

This was the context in which the Mega PC was born...

Amstrad saw the increasing success of computers such as the Amiga and Atari ST and the console market i.e Sega/Nintendo. Just earlier the 386 was also hailed as a revolution in processor evolution from the 286. Amstrad knew that the availability of software was key to the success of any games system. At the same time games sales were key to the success of console/games companies such as Sega/Nintendo who received licensing costs from the sale of each cartridge. Sega for example were keen for megadrive to be everywhere hence the AIWA hi-fi with built in megadrive etc. To Sega, the more people that had the ability to run megadrive games, the more money they make. To Amstrad, they could tap into the lucrative gaming and get back into the pc market with having to start from scratch and by having a unique selling point. (The GX4000 is another story!). Other unique computers with USP include the Amstrad Integra (an all in one PC with built in TV tuner!! - this I believe may even be rarer than the Mega PC).

The processor...
It is not clear if it took Amstrad a long time to complete the R&D which resulted in the Mega PC being released with a 386 chip or if they were just trying to reduce costs by using the cheaper option. For whatever reason the Mega PC was underpowered and looked bad value for money to the consumer.

The Mega PC Plus....
Amstrad could have fixed this issue pretty easily by replacing the 386 chips with the 486 SLC chips in the manufacturing process. It is not clear if they had already manufactured so many 386's Mega PC's (which have soldered chips) and these were waiting in warehouses/retail outlets. Maybe it was a catch 22 situation, they couldn’t change to 486 chips until they had got rid of 386 mega pc's. (This could have been one of the reasons why they reduced the price drastically to £599 to get rid of stock?).

In line with Amstrad ethos of reducing cost, they also had a line of computers which included 486 PC's that used 386 motherboards. Amstrad simply added the pin compatible 486 SLC chips onto the 386 motherboards.

Note: I have never seen a Mega PC plus (the Mega PC was heavily advertised in Amiga magazines but don’t remember seeing an advert for a Mega PC Plus). Can anyone confirm this???

If the Mega PC Plus was released or was planned, it was likely to have a pin compatible 486 SLC chip installed. These chips were mainly manufactured by Cyrix and Texas Instruments who manufactured a cheap option for people to upgrade their 386's without having to change their motherboards i.e the clip on upgrade 486 DRX/SRX etc. They also produced standard DLC/SLC chips which manufacturers could use on the existing inventory of 386 motherboard stock (the likely option for Mega PC Plus).

Upgrade options for current Mega PC owners:
Option 1: Clip on upgrades:
Based upon research the standard Mega PC contains a soldered 386 processor. There are clip on upgrades as identified earlier and as demonstrated in my own Mega PC. As the PC is so old I am assuming that the processor upgrade can only match the bus speed i.e mine is a 486 DRX2 50 which is twice the speed of the 386SX 25 (25mhz BUS speed). I cannot be certain if it has to match the bus speed. It may be that the Cyrix chips just doubled the speed and added the 486 instructions but I need someone who knows their stuff in this area.

The 486 upgrade requires some software to be installed with means the computer utilises the extra cache. Interestingly Texas Instruments (TI) chips are meant to have more cache than the Cyrix chips (8K vs 1K). This would mean that 486 SLC chips produced by TI would be faster than the clock equivalent Cyrix chip. TI produced chips for Cyrix but then they licensed the right to the technology and produced a better chip. It is unclear whether TI manufactured a clip on upgrade. Cyrix certainly did.

These clip on upgrades seem to be very expensive as they are sought after by DOS retro gamers, vintage computer hobbyists and CPU collectors.

List of 386 to 486 upgrades compatible with the Mega PC:
Cyrix DRX 2 50
Cyrix SRX 2 ??

Clip on upgrades may come with a heatsink that go over the chip?

Forum members please add to this list. Also need more info if AMD produced upgrade CPU's and the IBM Blue Lightning CPU

Option 2: Solder 486 SLC chip?
The other option which I have never confirmed but have seen discussed on different forums is that as the 486 SLC is pin compatible with the 386. You could remove the 386 and resolder the 486. It is important to note that there are two voltage ranges 3.3v (which I believe were laptop CPU's) and 5v (desktop - what you would need for a Mega PC).

This is probably the riskier of the options.

Forum members please confirm how to check whether chip is 5v vs 3.3 (apparently something to do with writing on the chip)
Also need someone to actually solder a 486 chip and see if it works!!!

Option 3: Compatible Motherboard Donor
Amstrad produced a number of PC's which may be compatible with the Amstrad Mega PC casing. The Amstrad PC7486 SLC has been confirmed by retrojunkie as a ideal replacement. Looking at the pictures, this PC was released as a slimline PC and therefore would fit into the small PC base unit used by the Mega PC. It may be worth checking slimline 486 PC's and seeing if they match the arrangment of the ISA cards of retrojunkie's 486 board or a standard Mega PC board. These could be then used a donors to upgrade/save any Mega PC's. (Looking at my own Mega PC, I am assumming the motherboard is smaller than a conventional board of this time).


This is also a low risk approach as there is no damge and Retrojunkie has provided motherboard jumper settings.

Confirmed Donors
Amstrad PC7486 SLC 33

Forum members please add PC's fit the profile.

Maybe add dimensions of motherboards when I get a chance to take it apart.

Thats it on the processor front. I don’t know if this was long winded and if thread readers want me to stop and not carry on with the other components let me know.

 

Very nice post. From looking around the 386SX / 386SXL seems to be the low voltage version at 3.3V. Apparently transistors reached a point where they couldn't handle the 5V that was being supplied back in the day. The packaging of these CPUs are all 100-pin QFP. So I'll just get really good at this and upgrade to a compatible chip on my 386SX board. Where to find a 3.3V CPU though.... Searching... Searching... Searching...

 

If we can get a collaboration with the vogons (non Hitchhikers guide to the galaxy related ) forum. Then maybe they could answer some more, "swaaye" who is a member here just like me. is also member of vogons, but I seem to have a reputation . That makes me hold back some of my "concentrated headaches/moments of pure brilliance" when it comes to ideas. But the guys at vogons are bloody intelligent too, and they know their shit. When it comes to computer parts. Especially about the intel platform. When it comes to knowledge that could maybe help people in their venture into megapc land, so to speak. But anyway I am just throwing ideas out, that could perhaps help So maybe swaaye could be arsed/asked to ask over at that forum. And yes, my reputation is a weird thing at times. When in fact I am just more into telling the truth with an array of EXTREMELY colourful language. In the sense of the famous 7 words, that you used to, not to say on TV. Since you could just not say them, in USA. Without being censored and what not.

 

Hi Wolverine - Im a member of vogons as well as other forums similiar to vogons. Ive asked a few questions on there and they are helpful.

I did receive my second Mega PC today with monitor, tested it and it has the familiar battery dead issue (although advertised as fully working apart from a faulty power switch.) I opened it up and there seems to be a little leakage but doesnt seem to have spilled onto the mobo.

The faulty power switch was on the monitor not on the actual pc and seems repairable (to me). This one has DOS 6.22 and Windows 3.1 wheras the first mega pc has DOS 5.0 and Windows 3.11

Im waiting for the rechargable 2032 batteries to arrive but they are taking their time. I did buy a brand new nicad and am in two minds as to whether just to have it fitted as they do last for a good few years....but then again a 2032 would be easier to replace so will wait a longer. Retrojunkie - was the damage on your motherboard on one side or both sides of it or just the side with the battery?

I learnt that my original mega pc has had the drive compressed (has a drive H as well as C which gives it more capacity) and Ive taken a picture of the startup screen showing the 486 processor cache software being installed. Im worried about not being able to find the original cache software and my hard drive failing in the future resulting in losing the 1k cache for the 486 upgrade. Ive ordered an USB to IDE cable so that I can copy the hard drive.

If anyone can get hold of the original cyrix drx2 50 disks/files I would be grateful

More pics have been added here:

http://s1269.photobucket.com/albums/jj587/limboy777/Amstrad Mega PC/

I have got an advert showing that the Mega PC Plus did exist (check photos). It was a 486 SX 33 - the exact same as retrojunkies!

 

My power switch on my Mega PC screen is borked as well, it won't always stay in so when I did get it to stay in I just left it on and switch off at the wall to power it down. That said there is also an issue with my screen where the stand pushes onto the PCB of the screen and causes the display to collapse into a single horizontal line in the middle of the screen. Lifting the back of the screen causes it to work properly as it lifts the pressure off the PCB.

Both sides of my 386SX motherboard were damaged pretty heavily. If you have a look here you can see the various damaged tracks and battery acid all over the place!

Wow! That advertisement is VERY nice, any chance of some high resolution scans? It is far nicer looking than the other one that is floating around on the net as it has the 486SLC! VERY NICE FIND!

I will admit I am sidetracked at the moment from the Mega PC world as I am trying to get the TeraDrive booting some sort of GUI. Only catch is that the GUI has to fit on a floppy. Managed to get Windows 2.1 working. Going to try for Windows 3.0 as I am more familiar with it. Dual floppy drives is a blessing for installing. I really should start a TeraDrive thread... Ah well! Keep up the good work on this one though. You sure are coming across some kickin' hardware and documents! How do you even get two Mega PCs? You must be local to the UK!

 

limboy777: Yeah they are helpful, I am just getting a bit tired of a member calling me a dopehead. Just because I some times smoke hash. And he uses it as an excuse every time, he does not get my long messages. But oh well, he is either a copper, or a bloody wanker who lives in a country where the laws, and their prison system are pretty much fucked up. But other than that, then vogons is a cool forum.

 

My monitor came with a piece of plastic shoved in to keep it on. I do the same as you. Co-incidently the person Im going to get to solder my battery is an ex TV repair guy, he may be able to help. If I get to watch him, Ill let you know how he fixes it.

The advertisement was a printout from the seller. I will scan it for you but will try and get the original file of him.

I opened up my mega pc (new one) and took the battery of today. I took a few pics on my camera and cleaned up the battery acid, it seems it was only a tiny bit so should be ok. I did this whilst lookin after a two month old and a 3 and a half year old! (Was doing it one handed!). This one has a vga memory expansion so this will be useful (ill post a pic up later)

My battery holder has arrived but reading up on this, im in two minds as some parts of the internet state that you should use a rechargable 2032 battery whilst others say just use a normal one!

Re terradrive - i dont blame you for concentrating on that. If you see another available for sale, I would be grateful if you could let me know.

Re software/os for terradrive. - I found something called Kolibri OS which is a linux GUI os fits onto one floppy! not tried it but looking at experimenting with different OS's until I get something that runs decently and looks good. (personally I like the original sega software on your terradrive - you should have some software to develop your own games ? is that correct ?)

You are right I live in the UK.

 

Geez! Where to start. The whole day got away from me. I just kept making floppies and remaking floppies - good thing they are rewritable!
Ended up with Windows 3.00a running on the TeraDrive - it works a treat from a RAMDisk I crammed it on.
Couldn't really head any higher due to system requirements skyrocketing away from my poor 286 with 2.5MB RAM.
If you are interested feel free to have a peek. It's got my thought process down below, video should be up in the next day or two.

TV repair guys certainly have the knowledge - it's either that or a nice big ZAP every time they make a mistake... That's what I call motivation!

Ah Kolibri OS, I did see that but the requirements are way too high for this little 286!

That means the seller must have either an original or a kickin' digital copy of the advertisement! That would be amazing if he would hand a scan or copy over! Do what you can, but don't make them angry! Muhahaha!

The battery. Yes the battery. I can understand your hesitation, I had a check of my board and it appeared that a line ran in straight from the AT power plugs through to the battery. What I'll probably end up doing (if the traces aren't already corroded through on mine) is cutting through the trace that provides voltage to the battery and wire in either a CR2032 or BR2032 - these are not rechargeable types and will definitely make a big bang / small or even large house fire if installed wrong!

The 486SLC should be fun when I get around to cutting apart one of those DS1287 chips and soldering / hot glue gunning in a CR2032 / BR2032 battery holder. Mine are on the way, still a few weeks off though.

Keep us posted of your progress though, especially.... well everything you have said! It is all useful information to have! :loyal:

 

Hi retro junkie

Will keep you informed. I might end up with the replacement nicad one in the end and just replace it every couple of years (they are meant to last 5 years). I read up up on another forum about using a diode to the cr2032 which means the voltage goes one way. I will try and get more information. (I might wait just wait to see what you do! before I do anything). Im also thinking about installing the battery away from the motherboard by running a wire from the the the original position. (I could put it in the corner of the case where its easily accessible and wont do any damage should it leak, this way I dont have to worry about putting in something non standard).

Ill speak to the seller but I want to moan about his "false" advertising and then ask him for a digital copy/scan of the advert!

Apparently there are 286 to 486 (as well as 286 to 386) upgrade chips available but they still run slow because of the underlying limitations. You could google this. Forgot that the terradrive is 286 - looks like you dont have much choice...

 

Saw your pics. Does the model 2 not have and ide controller? and ability to add a hard drive?