robcfg wrote:I think that replacing the roms is such a cheap option that may be worth the try
OK Rob you talked me into it
Having spent £30+ on replacement parts though I'm at the point where I've got to be sensible and cut my losses
If its a cheap option then I'll give it a try before giving up completely on it.
robcfg wrote:I'll take a look and see if I have any spare eproms, and if that's the case, I can program and test them. If everything work, I'll put them on their way to you.
I get the impression that it had problems with the ROMs before I got my hands on it. IC17 was already socketed and it had two different looking ROMS in IC17 & IC18. Looking at the motherboard pics on this site, IC17 is the type shown in the MKII Issue 5 revision and then IC18 is the type shown in the MKII Iss 6, which is the board that I have. I don't see any motherboard shown with the ROMS from different manufacturers or chip suppliers, or with only one of the ROMs socketed!
robcfg wrote:Edit: I forgot to tell that an easy way to rule if the roms are damaged is trying a cartridge. If the game shows up, then definitely you need new roms. Also check for bad connections or corrosion around the rom chips.
I've checked for any obvious problems around the ROMS and there doesn't seem to be anything along the lines of corrosion or shorts. I took the time to socket IC18 with the idea of replacing the ROMs, but I only have an old Watford EPROM programmer for my BBC Master and no compatible 21v 24pin EPROMs, so that idea went on the backburner.
I do have a cartridge but its empty with no EPROMs or otherwise in the sockets. With both of the ROMs now socketed, I did try the Dragon without the ROMs in and I got the same @@@@ symbols and columns as I did when the ROMs where inserted.
Mart