I don't have any first hand experience with the boards, but they just seem a bit scammy to me. I would guess that Octek should have had access to the same DRAM and SRAM as every other manufacturer at the time. That would be 15ns for SRAM and 60ns for DRAM. It seems to me all they did was move the SRAM off the motherboard onto the SIMM. Those SIMMs were kind of expensive and hard to get from what I understand, especially the higher density ones.
I am no expert on L2 cache, but I believe that having 256kb cache should cover more than just the first 256kb of DRAM. It should infact cache the first 64MB of DRAM (depending on the board design of course). There are many different types of caching strategies, and I would imagine that a good design would yield pretty good hits.
Does anyone in here actually have a DCA board that confirm whether or not these are any faster than a standard 486 board or just a big marketing scam?

jumper settings
http://support.octek.com.au/Products/MainBoar … /mb_234_006.htm

bit of info
http://www.zisman.ca/Articles/1995/Octek.html

slightly different opinion
http://www.redhill.net.au/b/b-95.html

I remember Octek. I owned a board from them and it worked rather well. Went to trash along with several 286 up to 486 stuff, years ago when nobody wanted old stuff (myself included)... 😢

I don't have any first hand experience with the boards, but they just seem a bit scammy to me.

A little bit, yeah. 🤣 That's what I'm curious to find out. I find weird technologies like that to be fascinating, even if they don't live up to their claims.

I don't think the 'EDRAM' thing was really exclusive to Octek, but they were the only ones to really jump on the bandwagon. Why that is, I don't know. It could very well be that the technology just wasn't that great. But then again, it might be something that was actually innovative, but never caught on due to market forces.

I have a rather limited understanding of how caching works, but as you pointed out, some of the claims do seem a little off. It sorta makes sense... even with good cache prediction schemes, there are certainly going to be plenty of instances where something has to be read directly from the main memory... but I'm not quite clear on how adding cache into the RAM chips themselves is supposed to get around that. Technical details on the system are rather thin on the ground.

It's a good board to have as a conversation piece, I suppose. Also, I wouldn't expect it to run any worse than the average 486 board. I remember there being mention of DCA on the Redhill website.

I'd love to get one of those boards and peel the stickers off the chipsets. I'll bet there's a UMC or a Sis logo under those stickers!

I'd love to get one of those boards and peel the stickers off the chipsets. I'll bet there's a UMC or a Sis logo under those stickers!

Actually, from what little info I could find, it's a Headland HT340 chipset, plus some sort of additional controller chip for the cache system. According to Red Hill, the DCA2 had an Opti 802.

And yeah, that's pretty much why I got it, just because it was interesting and unusual. I have no particular expectations one way or the other, with regards to how well it'll work... and even if it turns out to be a flaky POS, it won't be any worse than the other 486 board I have. 🤣

Old Thrashbarg wrote:

And yeah, that's pretty much why I got it, just because it was interesting and unusual.

I think many of us would buy interesting hardware in the same fashion.
A couple months ago I was at a flea market and saw someone selling very old stuff for way too much (like €15 each for a 4GB harddrive and a Voodoo1).

So I walked around these items, had a look. He asked me if I wanted to buy them and I said "I'll just look around the rest first" (while thinking in my head "Dammitz, I want those!!!1"!! 😁).

So 10 minutes later (the time it usually takes me to see all items on a whole fleamarket, I'm QUICK with the eye at spotting things 😉 ) I walked back and told him if he knew what the stuff was that he had.
I told him "Well, this is a 500 meg harddrive, but you'd be lucky if you sold it for €1. But don't toss it because of this! Theres still people looking for these 😉".
"Ok, this harddrive is 4GB, but still maybe €2 at best".
This is an old 3D card with 4Mb of RAM (I see him thinking "Damn...4Mb is nothing!").
In the end I bargained him down to €3 for 2 cards:
-A Voodoo1 aaand...
-An ISA Creative TV card?!?

The ISA TV card thingy alone was well worth the price if you ask me, if only to silence my curiosity. It looked badly scratched but I thought "It -might- actually still work".
Can't remember the CT number but I remember it had an i750 chip on it.

Sometimes you see weird stuff that catches your eye.

Well, the board arrived today. Dude-guy shipped it loose in a box, with just some of those air-filled bags... not cool, but hopefully it works anyway. It looks to be in decent shape, the battery is a bit corroded as I expected but nothing too bad.

Unfortunately, the included memory is not the special EDRAM... it's just regular EDO, and 70ns stuff at that. I think I'll still hook it up and see how it does with no cache, but I don't forsee it going into regular use unless I happen upon some of the correct sort of memory. Oh well, ya pays yer money and ya takes yer chances, I guess.

Edit: Alright, removed the battery, cleaned up the board, and it does boot. It doesn't seem to much like my VLB SCSI controller, though, and since that card also contains a floppy interface, I'm kinda outta luck on booting to any sort of OS until I can dig up my old ISA IDE/floppy controller card.

So, it turns out there may yet be hope for equipping this board with EDRAM. I expected the stuff to be nigh impossible to find, since it was only used on a couple models of motherboards. And, loose SIMMs of it are pretty scarce on the ground. However... I discovered that the stuff had another use, and a much more common one: cache SIMMs on certain models of the DAC960 SCSI RAID controllers that were so popular in '90s servers.

Now, I'm not going to go running out and buying up a bunch of RAID controllers off eBay just to get the RAM, but I do run across those things on occasion... and now I know what to look for.

Old Thrashbarg wrote:

So, it turns out there may yet be hope for equipping this board with EDRAM. I expected the stuff to be nigh impossible to find, since it was only used on a couple models of motherboards. And, loose SIMMs of it are pretty scarce on the ground. However... I discovered that the stuff had another use, and a much more common one: cache SIMMs on certain models of the DAC960 SCSI RAID controllers that were so popular in '90s servers.

Now, I'm not going to go running out and buying up a bunch of RAID controllers off eBay just to get the RAM, but I do run across those things on occasion... and now I know what to look for.

Now THATS smart thinking!