Post a photo.

its this one: https://stason.org/TULARC/pc/motherboards/A/A … REMIUM-286.html

so the fastmem card attaches from the 16 bit isa to one of the special connectors on the other side.

Looks interesting. I have one memory card, but have no idea for what system. Probably some 386 as it has 8x 1MB SIMM installed.

been slightly thinking about if an esp32 could act a memory controller. Found some modules with 8mb which would be more than enough. Number of gpio might be questionable. Maybe with some multiplexing it could be possible. It would need voltage level conversion.
id be curious with anyone thoughts about this.

Interested in this. Is there a theoretical limit to how many mb could be installed on such a card?

Would it work on a 486 class system?

to OP: Nope those boards require a AST memory board, none of the Intel, Acer or other mem boards will work proper in it AFAIK unless it specifically states it works with an AST and that model.
Personally I never mess with any motherboard that does not have any DIP or SIMM memory sockets. Went down that road decades ago and will never go back ;p
BTW that 10mhz 286 will perform about 1/2 as well as a later clone 286-12 with on board ram due to the RAM needing extra wait states being routed off board iirc

Sphere478: The 486 board would need a direct socket connection to memory controller bus so memory is addressed with the onboard (know of no 486 w/o onboard) so most likely would end up being EMS only and slow... just a guess 😀

edit: fixed my grammer...

Sphere478 wrote on 2022-08-23, 01:58:

Interested in this. Is there a theoretical limit to how many mb could be installed on such a card?

Would it work on a 486 class system?

AFAIK/AFAIU (please correct me if wrong) :

The ISA bus would limit things to 16MB of memory on the card (ISA addressing limits).

Additionally, that memory would need to be mapped/addressed as the first 16MB in the system (due to aforementioned ISA memory address space limits), so adding additional memory beyond the 16MB on the ISA card using a 486 (or 386) motherboard's onboard SIMM memory slots would require being able to map that onboard memory above 16MB, which I doubt is doable on most (maybe all) 386/486 motherboards .

Furthermore, most 386/486 systems allow onboard memory expansion to 16MB or more on the motherboard .

Finally, that 16MB of ISA memory would be accessible at ISA bus clock speeds (nominally 8 or so MHz) over a 16-bit bus, which would be rather crappy on 386DX system, let alone a 486 .

EDIT : There might also be compatibility issues preventing this from working at all .

EDIT2 : As Horun mentioned, use as EMS might be possible, but would still be slow.

EDIT3: It can work Help!- Compaq Portable 386 with 16MB ISA Kingston Ram Card , at least in some cases

@Horun any idea what the other connector is? ive wondered if it was access to another bus access to the cpu. I picked up the board as a part of a package and it very affordable and mainly out of curiosity). If i do get it working its not cause of how fast it could be compared to other systems. I can just use my 386 or 486 if i needed speed.

Here is my situation:

486 system with a vlsi chipset that seems to be limited to 32 mb of ram.

I have a POD 83 in it

I wanna try and put ME on it or at least 95. And play a few basic windows games but 32mb is kinda limiting.

In any case, I don’t mean to hijack the thread. Just curious.

Was kinda wondering if isa ram was a option. Slow sure, but prob still better than page file.

Sphere478 wrote on 2022-08-23, 02:57:

Here is my situation: […]
Show full quote

Here is my situation:

486 system with a vlsi chipset that seems to be limited to 32 mb of ram.

I have a POD 83 in it

I wanna try and put ME on it or at least 95. And play a few basic windows games but 32mb is kinda limiting.

In any case, I don’t mean to hijack the thread. Just curious.

Was kinda wondering if isa ram was a option. Slow sure, but prob still better than page file.

Thank you for providing more context.

As I mentioned before, AFAIK, you won't get more than 16MB of RAM through the ISA bus and you won't be able to map it anywhere other than within the address space of the first 16MB of system memory.

If you can find a way to modify the system BIOS to map the 32MB of onboard RAM above the 16MB mark, you might be able to get it to work with 16MB (ISA) + 32MB (on motherboard) RAM (no idea how feasible this or if you might hit some kind of chipset/memory controller limitation).

Additionally, if 32MB RAM isn't enough for your planned use case, I doubt that 48MB will be much of a game changer .

Feel free to try and prove me wrong . I enjoy reading about your (IMHO, sometimes slightly "zany") accomplishments/success stories. I write this with the utmost respect, BTW, as pushing the envelope in those kinds of ways is, IMHO, in the spirit of 80s and 90s computing .

Pickle wrote on 2022-08-20, 14:11:

Im curious if there ever has been a memory boards designed by anyone?
I have a AST 286 board and far as can tell there isnt any memory on board and i dont have the huge fast memory board.

I thought I read about someone trying to clone a vintage board of this kind a while back, but can't find a reference to to that now .

darry wrote on 2022-08-23, 04:26:

Thank you for providing more context. […]
Show full quote

Sphere478 wrote on 2022-08-23, 02:57:

Here is my situation: […]
Show full quote

Here is my situation:

486 system with a vlsi chipset that seems to be limited to 32 mb of ram.

I have a POD 83 in it

I wanna try and put ME on it or at least 95. And play a few basic windows games but 32mb is kinda limiting.

In any case, I don’t mean to hijack the thread. Just curious.

Was kinda wondering if isa ram was a option. Slow sure, but prob still better than page file.

Thank you for providing more context.

As I mentioned before, AFAIK, you won't get more than 16MB of RAM through the ISA bus and you won't be able to map it anywhere other than within the address space of the first 16MB of system memory.

If you can find a way to modify the system BIOS to map the 32MB of onboard RAM above the 16MB mark, you might be able to get it to work with 16MB (ISA) + 32MB (on motherboard) RAM (no idea how feasible this or if you might hit some kind of chipset/memory controller limitation).

Additionally, if 32MB RAM isn't enough for your planned use case, I doubt that 48MB will be much of a game changer .

Feel free to try and prove me wrong . I enjoy reading about your (IMHO, sometimes slightly "zany") accomplishments/success stories. I write this with the utmost respect, BTW, as pushing the envelope in those kinds of ways is, IMHO, in the spirit of 80s and 90s computing .

Thanks 😀 that build where I stuck debian jessie on a m.2 mvme on a 430tx/k6-3+ was fun 🤣 (technically, aborted the install, but it was working because it ended up slower than a floppy drive haha) definitely zany 🤣

Well, actually that may be enough to help (48mb).

But bios modding isn’t in my skill set. (Yet..)

It’s cool to know that it might be possible though.

I probably won’t peruse the 16mb isa card idea very far. But in the meanwhile I did order a set of 32 chip simms on a wild hunch that more chips and maybe running some address lines in bodge wire may allow me to get 64 mb working. That should be perfect for my uses! 😀 fingers crossed!

I wonder if maybe a option rom could be made for these cards, like a universal card with a rom that re maps the memory its self. Kinda a plug and play thing with 16mb of edo on it and a rom.

so i think ive found something that could work. I found that lo-tech has designed 1 mb and 2mb boards, tex elec is selling them but its too much for me at this point.
Searching for more on the cards i discovered another board by sbelectronics. I asked him yesterday for the board files and he has uploaded them.

https://www.smbaker.com/8-bit-isa-ems-board-flash-disk-board
https://github.com/sbelectronics/misc-pcboard … aster/isa-flash

I know it wont be fast but I think it would be a fun project to put together and see i can get the ast board to boot. I also have another 286 coming with 256k so it be useful there too.

Pickle wrote on 2022-08-31, 01:06:

I know it wont be fast but I think it would be a fun project to put together and see i can get the ast board to boot. I also have another 286 coming with 256k so it be useful there too.

Hit there! Yes, this should work, I think. 8-Bit EMS cards are not such a big problem, I think. EMS is an external type of memory, anyway.
And it's not used by DOS itself all the time. Some 16-Bit EMS cards used 8-Bit transfers, too.
The 16-Bit portion was merely used for using higher I/O ports or IRQs or something.

What you're looking for to increase system memory is an UMB card, essentially.
It will provide usable upper memory blocks (in the UMA), but usually also allows filling the memory below 640KB (DOS memory, conventional memory).
Unfortunatelly, there's no real market for 16-Bit UMB cards at the moment.
People making those 8-Bit cards are usually big fans of the IBM PC 5150 and 5160 (they also make other stuff, say 8088 motherboards, XT keyboard converters, 8-Bit VGA cards).
They're kind of comparable to those C64 die-hards who refuse to support the Commodore C128 past its built-in compatibility mode. 😉

Edit: I did use an UMB card in both an 8088 PC and some 286/386 PCs.
It works. At least for providing UMB memory between 640KB and 1MB.
(Note: Video cards like VGA have their frame buffer pass-through window past 640KB).

Using 8 bit memory on a 286 is a big deal. Yes, it "works" but it's a huge bottleneck, regardless if it's EMS or not.

Ive been thinking about this and ive been wondering if one of these designs could be extended to support the additional 8 bit data lines. Ive imagined the sram chips could be changed to x 16 variants and then some logic to only drive the other byte if MEMCS16 is true.

lo tech also has their 1 mb design on the wiki. Id like to review this a bit and see how it compares to the ems card.

Edit: this chip looks it could do it all
https://www.mouser.com/ProductDetail/Renesas- … yIdrE8xiw%3D%3D