CPC464 + Colour Monitor, not working out of attic...

[JD]

Hi everyone,

Well I'm about to move to a place where I've finally got room to have an Amstrad CPC 464 set up - I've had one in the loft for a few years that I bought from a friend. It was working when I put it up there, but now it appears to be broken. I plugged the colour monitor and computer in, and when I pressed the power button on the monitor it sounded ok, the light didn't come on on the main unit. I found that the power switch was off on the main unit (I'd forgotten there was one other than on the monitor) and I'm not sure if the red light came on straight away, because I'm sure i tried the switch a few times without success. Anyway, at some point I noticed that the light was on, but I had no picture. The monitor was on, and I think it was simply scanning out a black screen - I tried playing with the brightness, when it was right up I could occasionally see some white lines of electrical interference across the screen, but no sign of blue. The tape deck could rewind and fast forward okay. And when I power the main unit off, I can hear what I think is the speaker click. When I power off the monitor, I get a bright white flash/shrink effect, as you would expect from turning off an old CRT. This makes me think it's at least partially working.

I'm hoping someone has some idea of which part of this set up is broken. If it's the main unit I'm pretty sure I could stretch to obtaining a new one on ebay, but if the monitor's bust then I'd probably give up.

I have to admit, I dont know much about the CPC - really I'm of C64 heritage. If the monitor's broke (apart from providing power to the CPC) can I type in a basic command and hear a sound? Is the speaker on the main unit? I don't remember unfortunately.

I start moving things over to my new place tomorrow so I'll have to make a quick decision on whether the CPC comes or it goes...

Thanks,

Joe

[steve]

It is looking hopeful, take it with you and sort it out later.

Press any key on the keyboard, when it gets to the end of the line (255 characters), it will start beeping.

[00WReX]

Even easier is to simply press the "CLR" or "DEL" keys after power on to get a beep sound.
Make sure your sound is turned up...this is next to the ON switch.

Also, what I'd do...as it may have been in a slightly dusty environment is (with everything powered off).
Plug & unplug the connectors from the Monitor to the CPC...do this a number of times just incase they got a bit dusty and not making a good connection. With the monitor off turn the brightness knob up and down a few times. Also switch the CPC on an off a number of times (still with the power off) just to give the switch a bit of a workout and maybe get the contacts making a nicer connection.
Basically give all the switches and connections a bit of a workout without any power connected to make sure the contacts are all good.

I actually had this exact same thing happen back in 2003 when I got a 6128 that appeared dead.
I powered it on & off a couple of times and thought, OK it's dead...tried once more & noticed the Power LED flicker.
I then unplugged it and as above continually turned the CPC on & off a number of times...This CPC is still working perfectly fine to this day and I have done nothing else to it.

Anyway, always best to try the simple things first...

Cheers,
Shane

[JD]

Hey guys,


Thanks for those two replies, I thought I had responded to them before but must have dreamt it... I tried out the tips for making noise from the keyboard unit, not a peep out of it unfortunately. So I reckon theres something shorted or broken inside.


The good news is I kept the 464, and brought the whole lot with me. The bad news is, I still never succeeded at getting it working. I've now got a more pressing need to do something about it, other than my initial desire to play some games on it. I have a game in development which is about 75% done on both the C64 and the ZX, and I wanted to complete the set (and make the most of my Z80 source) by taking it onto the Amstrad as well, and it'd be nice to be able to test it on a real machine and also do some tape loader work.


I'm going to gamble on my monitor working correctly. I've looked at CPC 464 keyboard units on eBay, it seems a bit of a minefield - so many sold untested, often listed at exorbitant prices, and something I've never understood about the 464 on eBay - why are so many pick-up only? Yeah I know the monitor's heavy, but so's a lot of stuff you could buy on eBay, and it's not usually pick-up only. It'd be going onto a postal service van, not the back of a donkey. And sometimes the keyboard alone, listed as pick-up only -  what is it about the CPC that makes people so reluctant to carry it or drive it to a post office? Incidentally, I only ever came to have one because a friend was selling it, never could find a good opportunity for one on eBay. Anyway, I've totally digressed there. I saw that there was a post (started a few years ago) by someone saying that they'd fix CPCs for €30, that was in Portugal and I'm in the UK. I imagine posting the keyboard alone to Portugal would be pretty expensive on top, and then it'd have to come back. Is there anyone in the UK that would be willing to take a look at it, or should I be thinking about taking a chance on a potential dud from eBay? Just curious about other's opinions.


Thanks again!


J

[dragon]

If you   search buy a new cpc,I Think maybe is best to you buy a 6128.And you can use tape+disk.


Merlin serve have 464 and 6128 keyboards and monitors,i not know the price,but they are in u.k.


Merline-Serve

[endangermice]

I agree with dragon, getting a 6128 would be worth it, especially if you want to use it for programming - the ability to easily hook up a 3.5" drive makes transfer from a PC a lot easier, it's what I'm using.


If you do go for a 6128, don't forget you'll also need to get a 12v DC power supply for the floppy drive from somewhere - also if you do this please note that the drive power is reverse polarity!


Rather than eBay, I would recommend end placing a wanted advert on Amibay. The guys on there are genuine enthusiasts are are trustworthy - you can check them out by their reviews, any bad eggs soon get negative feedback and ultimately banned! You also tend to get machines for lower prices than you see on eBay and you can strike deals with people from outside the UK increasing the number of machines available. As an example I recently got a 6128Plus (French edition) fully working including the 3" drive for £50 - quite a lot less than the frankly ridiculous eBay asking prices of £150 plus for machines that often are broken!

[dragon]

Yes,and if you search programing to the plus series is best yo search a 6128 plus.

[endangermice]

Especially since they removed the disc drive connector from the 464Plus!

[MacDeath]

Especially since they removed the disc drive connector from the 464Plus!

If it was only that... they actually removed a shitton lot of components...


(the 6128PLUS also have a few chips removed... but hey, who use Tapes when you can have Disks...?)


I wish CPC Parts : Parts for your Amstrad would sell some kits with all the proper components/chips to add the tape to a 6128PLUS or the disk+RAM to a 464PLUS...

[endangermice]

If memory serves they removed the FDC too. I presume no disc drive add on was ever made that connected via the expansion connector, I guess such a device would have been too expensive.


I think one of the problems with offering these parts is that some of the components can be quite difficult to get hold of especially in large quantities and that it's very much a niche area. People in the know are probably equally able to source the required components themselves though I agree it is something of a challenge and a kit would be nice but have a very limited market.

[MacDeath]

I presume no disc drive add on was ever made that connected via the expansion connector

can't you just use the Disk Drive that was used with CPC464 ? (the one with FDC)


Anyway, 464PLUS are for museum...
The real deal would be to have a kit to add the Tape on a 6128PLUS. certainly easier to find the components.
despite being "not as usefull" it would enable to havea "complete" machine.




If someone have only a 464PLUS, I pity him...

[JD]

6128 or plus would be cool, but really I need to go with whatever will give me a reliable machine at the cheapest price, which I expect will be a classic 464. Amibay looks promising, I've tried registering but haven't yet gotten a validation link in my email after 2 tries, although their first email arrived ok. If that turns up then I'll post in the 'wanted' thread. And I'll send an email to Merlin as well and see what sort of price we're talking about for a 464 keyboard.


I haven't really delved into the Amstrad cross-dev process very far yet, but I'm guessing that, like most old formats, I can pretty much develop the whole thing without ever having to test on the real hardware. So it's more of a want, rather than a need. It's quite a big want though because I've got a bunch of tape games I bought for it and want to play as well


And I'd happily have a 464+, I'm much more at home on beige computers anyway


Thanks for the advice again!

[ralferoo]

I haven't really delved into the Amstrad cross-dev process very far yet, but I'm guessing that, like most old formats, I can pretty much develop the whole thing without ever having to test on the real hardware.

Well yes. Both wincpc and winape both have good assemblers and debuggers built in. It's amazing being able to assemble to memory and then autotype "call &800" and even then to just enter the debugger and see exactly where in the scanline the CPU is. Makes making demos far easier than the real hardware.

So it's more of a want, rather than a need.

Except that things look much more amazing running on the real hardware, and also you'll find different incompatibilities on real hardware especially if you're doing CRTC work...

If you use Linux, I can give you my makefile as a starting point. I literally just type "make play" to assemble, compress, turn into a cdt, then play that through the soundcard to a cheap tape/MP3 adaptor. So, I can use the convenience of an emulator for developing and proving something and yet be running it on real hardware in a minute or so to be sure it does genuinely work! 

Of course, you might go a bit over the top like me and end up with a whole pile of CPCs just so you can test the code on different CRTCs...   

[arnoldemu]

It is true that you can cross develop on the pc for the amstrad.

Best to always run it on a real machine because you will find some differences even when you don't use crtc tricks. (colours may appear different.. sound may be different, timing of key presses may be different; e.g. emulator may do it at start of frame, but real cpc does it when you press it).

So with my games, I write them using an emulator, then in the final stages, I run on a real machine and iron out the issues.
If I am developing a demo or something that uses crtc tricks, I test early on the real system to ensure the timing is correct and then go from there.

Like ralferoo, I generate a cdt and then a sound file which I play back into my amstrad.

I too use linux, assemble for pasmo, use my own tool 2cdt to make a cdt file and playtzx to generate an au file which I play back using audacity.

Others generate dsk files and put them to real discs or an sdcard for Jeff's HxC device. Some program only on the real machine.
I find I am more productive with cross developing because I can use the emulator's debugger to trace through code and view memory and graphics and hardware state.
Helps me to find all those bugs I make 

[dragon]

And I'll send an email to Merlin as well and see what sort of price we're talking about for a 464 keyboard.

OH,remember Merlin-Serve not only sell cpc parts.They repair cpcs!.

[sid]

6128 or plus would be cool, but really I need to go with whatever will give me a reliable machine at the cheapest price, which I expect will be a classic 464. Amibay looks promising, I've tried registering but haven't yet gotten a validation link in my email after 2 tries, although their first email arrived ok. If that turns up then I'll post in the 'wanted' thread. And I'll send an email to Merlin as well and see what sort of price we're talking about for a 464 keyboard.


I haven't really delved into the Amstrad cross-dev process very far yet, but I'm guessing that, like most old formats, I can pretty much develop the whole thing without ever having to test on the real hardware. So it's more of a want, rather than a need. It's quite a big want though because I've got a bunch of tape games I bought for it and want to play as well


And I'd happily have a 464+, I'm much more at home on beige computers anyway


Thanks for the advice again!

I have a spare 464 and a spare 6128. I'm sure we could come to an arrangement for you to get one of them, though I'd prefer to do the transaction on Amibay. My username there is thecellartroll.

[Bryce]

I'd guess from your description that it's only the monitor that's broken. Buy or make a SCART cable and external powersupply (unless you want to use the broken monitor to power the CPC) and use it on a TV.

Bryce.

[JD]

@ralferoo That mp3-tape converter ideas genius, and I think I have one of those lying around too. My source code for the spectrum version of the game is assembling with sjasmplus, I don't think there's a direct way to build an Amstrad compatible emulator file through it, so I haven't quite figured out my approach yet. I'm hoping that by not using any of sjasmplus's unique features my code should assemble with few changes on a different assembler. I'll be sure to ask for a bit of help once I get onto it properly.


@arnoldemu I don't know if I'd ever have gotten into machine coding if it wasn't for cross-development, the quality and level of monitoring available and the speed at which you can test and adjust something makes all the difference. But you're right, at the end of it all you do need to see how it turns out on the real thing. Some of my nice sharp pixel graphics have ended up looking muddy on the ZX or C64 just due to the way those things scan an image to screen, I'm thinking in that respect at least the Amstrad version is going to remain fairly true to what I see on my PC screen, always been impressed by the quality of the colour monitor.


@dragon I've asked about repairs too, haven't had a reply yet but I only emailed yesterday.


@sid I got the email today to say I'm verified for Amibay so I'll be getting myself on there later.


@Bryce really? What about the lack of sound from the main unit? Incidentally, what would you expect to see on an Amstrad monitor if it was on but not receiving any video signal? Would it look almost like it was off, maybe with a very faint 'black noise' pattern? Because that's what I see. Also the screen generates static electricity, which makes me think it's scanning ok. The white lines have only happened while I'm actively adjusting the brightness control, presumably because it's an analogue component of some sort. I'll be very bummed if I find out the monitor's broken

[Bryce]

Ah, I must have skipped the bit about no sound So you get the LED, but no screen or sound, correct?

A screen with no signal would give a blank screen which flickers slightly. I wouldn't give up on the CPC just yet. Re-seat all the socketed ICs. Then measure whether you are getting 5V (across any of the electrolytic capacitors). Clean the pins / socket of the monitor connector. Post a picture of the screen you're getting when you have time.

The static just means that the HT (High voltage) part of the screen is working, but there are lots of other parts that may have failed.

Bryce.

[JD]

Re-seat all the socketed ICs.

It's alive! I can't quite believe it's worked, I had to look twice when that blue screen came up, but I'm really pleased! Thanks Bryce, to be honest I didn't even know that some of the chips were in sockets, I had the machine open last night but I just checked it for any obvious breakage or debris.

Well, looks like I'm not going to be needing a new keyboard yet (and the monitor's working perfectly too), but thanks for everyone's help on this. I guess my eventual next questions are going to be coding related so I'll use the appropriate sub-forum Also I wasn't aware of Amibay, it's really cool so thanks for the heads-up!

[Bryce]

Congratulations. Result.

When it comes to coding I haven't a clue, but there are many others here that can most likely answer all your questions.

Bryce.

[Gryzor]

Yay! Reseating chips sounds a bit suspicious at first and it's always surprising me when it works. I remember laughing out loud the first time I did the 20cm-drop on my ST and after having spent hours trying to figure out why it didn't work

[Bryce]

The problem is with the cheap and nasty sockets they used back then. They tend to oxidise and generally get dirty except for where the IC pins are sitting. Moving the computer after years of storage can shift the IC onto the oxidised surface and one or more pins don't make contact any more. Removing and reseating the IC scratches a new connection for the pin.

Bryce.

[Gryzor]

Yes, but IIRC this problem already existed when these machines were current?

[Bryce]

It can happen pretty quickly, especially if the machine is in the wrong environment and/or is in an area where the temperatures regularly fluctuate greatly. The old type IC sockets are generally always a source for a bad connection and line capacitance too.

Bryce.

P.s. I thought the correct height to drop an ST was 20 Metres?... I was always on the Amiga side of the fence