Phipli

@maceffects Were there ever any SE memory upgrades that didn't use virtual memory (and so also need an MMU)?

So could the contents of the Brainstorm be extracted from the firmware updater?

https://macintoshgarden.org/apps/brainstorm-accelerator I read older firmware versions needed drivers, but later ones didn't I think.

@maceffects These folks seem to have one. Anyone live close? Do you think they'd let someone borrow it? https://www.freegeektwincities.org/

Folks, look at what someone posted on the Facebook "Vintage Macintosh Restoration and Preservation" group. It is a 3rd party BBU that allows for a higher bus speed on the SE!

Are the bus arbitration pins like /BR functioning? Does the CPU think a peripheral is using the bus?

@quorten I'm trying to work out where I read details, or if I ever did. There is some info in the "Guide to the Macintosh Family Hardware" but I've not found a full description - the other place I might have seen it is in "Designing Cards and Drivers for the Macintosh II and SE", but I haven't checked yet. I'll keep looking. Are there any memory map issues? I know expansion boards tended to implement extra RAM using virtual memory and a RAM disk. I'm several steps beyond my understanding though as I've only ever read stuff to do with SE RAM with a passing interest, rather than with the intenti

I think I remember that the RAM refresh is linked to the screen drawing and so you need to do more than break out the address lines - the design was optimised by linking the two, but it means there isn't RAM refresh circuitry for much more than 4MB... I'm likely to be mis-remembering

What years are the boards? Are they from the Cork factory?

Well, while I'm at it I thought I might as well upload my SE reference photos in case they are any help more generally. http://stuffandnonsense.elephantandchicken.co.uk/?p=1292

I zoomed on the original photo and it is brown 21 it is!

Although in my photo it looks more like 27 or 28? Doesn't look brown... Edit : looking again it could be. Sigh, you'd think it would be easier to tell!

@quorten Interesting. So I'm probably better off dropping a 3.6v in it. I thought I'd gone the extra mile to keep it original (ignoring the socket I fitted).

Still have the original, let me know if you are interested in more photos - under "Ord. No. 6126" it says "MH 13654 (N)" - I think that means it is Manganese Dioxide? Mine is date code 0188. http://www.mercateo.co.uk/p/4888-6681/Varta_CR1_2AA_Lithium_battery_6127_UL_MH_13654_N_950mAh.html