Problem with +3e ROMs

[ChrisZx]

Just thought I'd put this out there, in case anyone has experienced the same and has any pointers.

I bought new +3 ROMs from the only source that I could find for them (now shown as out of stock) in Spain.

They came after a couple of weeks but after installing them all I get is a screen filled with question marks until it's full. No new +3 screen, nothing. I thought perhaps they weren't seated properly in the sockets so removed them and re-installed the original ROMs - which work fine. I put the new +3e pair back in and get the same screen of question marks.

They must be a dud new pair of ROMs, right? I have contacted the seller. Or could they have been labelled incorrectly i.e. A is B and B is A? Would it hurt if I tried swapping them over?

[Guesser]

Swapping them won't hurt, but I don't think it'll help either.

[ChrisZx]

I tried swapping them and the result was even more garbled. I also checked continuity between the tops of the legs to the solder points under the board - all ok. The supplier says they must be faulty and will refund me (not send replacements, annoyingly). I was really looking forward to running a DivMMC from a native +3-like environment.

Anyone know another source of 3e ROMs, or someone capable of creating them for me?

[ChrisZx]

I found someone else who can supply the ROMs flashed with the publicly available correct 3e ROMs. Hopefully they'll work this time.

In case anyone reads this in the future and would like pairs of A and B type 3e ROMs, I can probably supply them and I'd make sure they were tested on a real +3 before sending them.

[1024MAK]

I have a programmer that can ‘burn’ most DIL EPROM chips (such as 27xx, 27xxx, 27Cxxx series like the 27C256), and which can ‘flash’ various DIL EEPROM chips.

I also have a limited number of new 27C256 EPROMs.

Mark

[ChrisZx]

I was thinking of having a play with a programmer and/or offering the results to Speccy peeps, but I don't think there is a huge demand for +3 stuff in general. Are there alternate ROMs available for other Spectrum models do you know? And if so, are the originals even socketed!?

[1024MAK]

A lot of ZX Spectrum 48K and Spectrum+ machines have the ROM socketed, but not all. A significant number (especially the later production boards and maybe some of the very early boards) have the ROM soldered in.

There is only one official ROM for the ZX Spectrum 16K, 48K and Spectrum+ models, but there are some unofficial modifications and some independently written ROMs.

Note that ZX Spectrum 16K, 48K and Spectrum+ machines need a modification to the ‘ROM’ control circuitry if a EPROM is fitted.

I believe that most, if not all ZX Spectrum 128K and ZX Spectrum +2 (grey) machine’s have their ROMs socketed. And as far as I’m aware, all +2A, +2B, +3 and +3B boards have ROM sockets. None of these need modifications in order to fit EPROM chips.

Again, for the English version machines, there is only one ROM version for the ZX Spectrum 128K. Same for the ZX Spectrum +2 (grey). There are two official ROM versions for the +2A, +2B, +3 and +3B boards.

For more details visit these web pages/sites:

https://zxnet.co.uk/spectrum/roms/

http://www.shadowmagic.org.uk/spectrum/roms.html

https://web.archive.org/web/20150602175 ... mon.co.uk/

http://www.fruitcake.plus.com

Mark

[ChrisZx]

I found that 2nd page after posting the above. It seems there are copyright issues with almost all of them apart from the +3e by Garry Lancaster, and I suspect the added benefits of the other ROMs may be very few for actual modern usage, especially if fitting them requires de-soldering or other modifications.

I'm looking forward to having a play with the 3e and will report back on DivMMC compatibility and stuff!