helllllllllllllllp bryce pls with megarom

[FRAGKI-2012]

hello Bryce Is possible to help me about mega rom?? I make a clone from cpcwiki but not working!!!!!
I make exact like the site but in to the 50 pin edge I solder trough the 50 edge pcb connector !!
when I m going to plug the cpc freezes   and stop to work !!
I takeout the rom 128 and is working but the speaker make sounds but is in a full command working condition cat,icpm,ib,ia,etc
can you help me??? I can also not understand the paragraph that you say to put a switch    internal for the rom 7 me I only create the pcb and I solder the components nothing else!!!! is something else that I must make  to work the megarom ?
I want to put the future os in my cpc any help is very important to me!!! thanks in advace !!!!

[Bryce]

Hi Fragki,
    I answered your PM, but I'll repeat it here anyway:

First make sure that the jumpers 1 and 2 are set correctly so that the MegaROM slots 0 and 7 are disabled. When you say it freezes, do you mean you get a black screen, or is it blue with some text appearing but then resetting?

For FOS you don't need to use ROM 7 on the MegaROM, so the paragraph about the internal disabling of ROM 7 aren't important at the moment, you don't need to make these changes.

Could you take some pictures of the MegaROM PCB top and bottom side and possibly a picture of the screen when is freezes and post them here in this thread, this might help solve the problem faster.

Bryce.

[FRAGKI-2012]

THANKS BUT THE PROBLEM CONTINUES MABY IS THAT I MUST PUT THE INTERNAL SWITCH BUT TELL ME PLS WHAT PINS I MUST CUT AND PUT THE SWITCH
THANK YOU IN ADVANCE!!!

[MacDeath]

ouch, capslock mode hurts my ears !

[Bryce]

As I said in the PM. It should work without any internal modifications, so there's an error somewhere on the MegaROM. We need to solve that first. I doubt it would work, even if you made the internal changes.

A few pictures of the device might help.

Bryce.

[TFM]

I want to put the future os in my cpc any help is very important to me!!! thanks in advace !!!!

Hi! Well, I can't help with the hardware, but Bryce hopefully. About FutureOS: Usually you place the ROMs A, B, C and D at ROM positions 10, 11, 12 and 13 respectively. They do not interfere with any other ROM / DOS / OS. If you have any questions let me know.

[FRAGKI-2012]

[/URL][/img]    [/URL][/img] maybe is now better to help me !!!!!

[FRAGKI-2012]

for better size pls follow http://imageshack.us/photo/my-images/22/img0650ck.jpg/
thanks!!!!!!!

[Bryce]

Wow! I didn't realise you'd actually etched your own PCB. Impressive work! Even in the big pictures it's hard to see all the details. Have you checked that no tracks are shorted? Otherwise it can only be a bad solder joint. I thought you had hand wired it, then mis-connections would be possible, but with the PCB, all connections should be correct.

I've uploaded the Higher Res pictures here for all to see (I'm not a fan of Imageshack links)

Bryce.

[Bryce]

I've taken a closer look at the bottom of the PCB. There's a few points where the tracks are very close to solder points. You need to check that there are no unwanted connections where this occurs. I've marked a few examples on the picture below, but you should generally inspect the PCB and make sure no shorts are happening where a track is close to a solder point.

To make things slightly easier / quicker for you: I'm pretty sure that it's not a data bus track or address bus track that has the problem. It's very likely one of the outputs from IC3, IC4 or IC5.

Bryce.

[Gryzor]

Heh, this looks appropriately steampunk!

Thanks for bringing the pics in, Bryce!

[TFM]

Well, I just hope that the problem is not located underneath some of the components already soldered on the PCB.

[Bryce]

It's a single sided PCB, with just a few wire links under the ICs. So it could easily be repaired, even if the mistake was there, but I doubt it is.

Bryce.

[TFM]

If often happens that the lead runs from one pin to another underneeth some parts. So you have a connection wher you don't want one.

[FRAGKI-2012]

unfortunately I check thousand times the circuits before bother you and a few times after your last reply but nothing!!!! the only I cant say is if I m take out the eprom is working with some sounds in the speaker!!![only the eprom from the megarom not the megarom from cpc]
and if I put the eprom the problem appears any suggestions???

[TFM]

Can the problem be the EPROM itself? Did you try another one?


Or could the problem be the content or the EPROM. (If enabled) you need the BASIC at ROM positon 0.


Ok, you probably checked it already, but I got no better idea. Except measure for shortcuts on the PCB. But I'm sure, that you did that several times.

[FRAGKI-2012]

the problem solved!!! I was the connector that mixing the lines!!! I make a cable and now it is fully working!!! as I cant easily find the edge connector for cpc I make a mod see the pictures below!!!
http://imageshack.us/photo/my-images/16/img0659eu.jpg/
http://imageshack.us/a/img32/3375/img06611a.jpg

[FRAGKI-2012]

[Bryce]

Interesting solution. Glad it works though!

Bryce.

[TFM]

Good to see, it took a well end. After burning of the EPROM it's a good thing to get its crystal glass window covered, so that no light can go in.