AS always BP is interested  

I was just thinking about the idea of one PCB for both the edge connector and card edge...

I cant do it with a through hole edge connector, however its possible with a straddle mount type. This would then give a lay-flat type connection to the Enterprise rather than the vertical mount. I'll see what I can source in the way of edge connectors...

This would then give a lay-flat type connection to the Enterprise rather than the vertical mount.

I didn't realise lay-flat was an option - I assumed you wanted a vertical one! In that case I wonder if it is possible to solder two conventional edge connectors back to back (I haven't tried it!)? Hopefully all the pins being soldered together would give enough mechanical strength and you could then just connect card edge to card edge.

Count with me for at least one PCB!. I really like the vertical solution

Hi Saint,

Please count me in for an SD interface - happy with either version.

Cheers

Tricky

I'm not sure if I mentioned, but this expansion includes SD card interface, 512KB RAM (which I can put at any address, so if you have an internal 64K, 512KB or 1MB expansion, I can map lower to give you additional RAM) and 512KB FLASH ROM. The FLASH ROM will be managed from an EXOS extension, allowing you to select ROMs from EXDOS and flash them into the card so you can have up to 32 ROMs installed.

Cannot it be standardized ? Not for all expansions in the universe, but at least among your expansions, or with (maybe consulted with Zozo) most of the expansions ?

So you mapped the the inside expansions somewhere, and by default mapping the SD card versions somewhere else, and the third kind again somewhere else ?

So users could combine them as their wish by default, without collision in the most of the cases ?

No.

The problem is, if you have an Enterprise 64, and would like to run 128 software, the RAM needs to include pages F8-FB. If you have an internal RAM expansion then this is covered, and the extra RAM could appear anywhere.

The address of the RAM is programmed into a GAL, so you would have to specify which version of the GAL you would like when ordering. Either one or Enterprise 64 to allow 128 compatibility, or one for extra RAM (which can be a set address for all machines which already have F8-FB mapped).

If I had thought about this more in the first place, I could have made this switchable by software, however as people either have an internal memory expansion or they don't, then two GAL's was easier.

At this time, it's too late to design such expandable hw memory management ... it seems (how you say) manual configurations is an absolutely need ...

I should add the only reason that the memory needs to be at F8-FB is because of "naughty" programs just assuming that these memory pages are available. If they had been written properly using the EXOS memory allocation, memory could be at any address and we would have no problem.