Much the same as I thought, but nice to have it confirmed. The £99 price tag seems a lot less acceptable when you add in those factors.
Not a chance. Not only is it missing some of the RAM and a MEMC, it's missing the crucial PALs. The flying wire mess also makes me believe it's a no-hoper.
The A3000 board looks like it's a fair bit of work and not a simple solution either, but an interesting read nonetheless.Mr Jeffray hasn't even built it himself, and the reason it's languished unprogressed is because it relies on a copy of the PAL lifted from the A540 which has the nasty side-effect of needing to hold the ARM3 in reset until its happy the MEMCs are in sync, which means a track-cut-and-hack to the A5000 mainboard which is unnacceptable IMO. (See my A3000 8MB board for similar flying wire - it's not as bad on the A3000). You can do without the PAL and track cut, and just "Hope" the MEMCs are in sync - this happens maybe 50% of the time IME, but not very friendly. I really need some help with creating an 8MB sync PAL that operates as per the Simtec/Atomwide stuff which doesn't require this "one more clock" cycle and reset-hold-off.
I might do a build just to validate the design though. The MEMC adapter it also relies on also hasn't been validated, so that's another "to do".
A shame those limitations are holding it back, but I get the desire to leave the board un-hacked. For me with so many track repairs due to battery damage it would be less of a worry, but on the flip side would I want to modify an already fragile board and risk further issues? Probably not after all the issues I've had with it, I'd just like it to be stable and running.
And there is the other problem of my machine not having a socketed MEMC. While I am certainly capable of fitting a socket for it, do I want to risk damaging the mainboard? Probably not. I have seen designs on the Amiga 1200 where an inverted socket is used to clip onto a surface mounted IC. It works very well (It's an AGA Indivision that provides a DVI video output.) but obviously I couldn't say if it would work in this scenario, even if it removes some risk meaning the MEMC could stay on the board.
Given the cost of the upgrade (Based on what is available now from CJE) and the potential to damage the mainboard doing it, I think it's probably going to end up as a non starter.
Of course, should you ever move forward with your project I'd certainly be interested in building one.
What does surprise me a little is the 4MB limit in the first place given it's based on a 32 bit CPU, which is the same limitation the 16bit Atari ST has, assuming I read the specs right.
Thanks Ian, very helpful and informative
Statistics: Posted by Ronin47 — Sun Mar 02, 2025 9:27 am