I didn't think you could... SRAM SIMMS are a sound concept, but it would be a time-taking task and a half to design and fabricate from scratch.

Excuse my ignorance but who is VCF?

vintage-computer forum.

I don't think the project would be time consuming for somebody who knows the layout software well and has dealt with handling small orders before. The problem is convincing such people that this would be a worthwhile effort.

Ive had a little play with the UMC 82C481AF based 386/486 hybrid VLB board, no VLB video cards boot with the 386 CPU and I tried like 5 or 6 cards.
However it will boot a VLB controller card so go figure, I haven't done much testing in regards to stability with the controller but ill let you know who it goes, I wasnt able to overclock the cpu either despite having a 50mhz option I believe it only works for the 486 side of it.

dirkmirk wrote:

Ive had a little play with the UMC 82C481AF based 386/486 hybrid VLB board, no VLB video cards boot with the 386 CPU and I tried like 5 or 6 cards.
However it will boot a VLB controller card so go figure, I haven't done much testing in regards to stability with the controller but ill let you know who it goes, I wasnt able to overclock the cpu either despite having a 50mhz option I believe it only works for the 486 side of it.

Cheers for posting.

Yea I was really curious how the UMC would perform, I saw one on the bays which got away from me. How many VLB slot's does your board have? If it has more than one, you could maybe be putting your graphics cards into a slave slot... from what I understand VLB graphics cards should always be put into the primary VLB slot, which if it isn't marked... is ussually the closest to the CPU.

Anonymous Coward wrote:

vintage-computer forum.

I don't think the project would be time consuming for somebody who knows the layout software well and has dealt with handling small orders before. The problem is convincing such people that this would be a worthwhile effort.

Still... i'm suprized, if it is possible, that it hasn't been done before. I guess there just isn't enough of a demand, or if there is... there isn't recognized to be one. If it is really possible/available... I would of course be curious enough to try, but i'm sure they would be quite expensive in the process.

I forgot. I still have one more hybrid board left, but it's an IBM 486SLC2-66 with VLB, so the VLB slots are gimped even further with a 16-bit data and 24-bit addressing restrictions.

Anonymous Coward wrote:

I forgot. I still have one more hybrid board left, but it's an IBM 486SLC2-66 with VLB, so the VLB slots are gimped even further with a 16-bit data and 24-bit addressing restrictions.

32-bit slots on a board that only has a 16-bit 486!? This kind of things puts me off proprietary vendors like IBM. The only thing that I would like to try IBM related is (if available) at somepoint acquire one of their blue lightnighting chips (DLC3) that has the 16K L1 cache, and the related 132-pin PGA socket adapter, aside from that they don't seem to be very adaptable.

The Alaris (IBM) boards are all of excellent quality. I would guess that despite the SLC2-66 not having true VLB slots, performance wise it should be at least 90% of a true Intel DX-2 66, mostly because this board uses memory interleaving whereas most mainstream 486 boards do not.

I had a friend with an SLC2-50 system without L2 cache. His system was more or less the same speed as my 486DX-33...except in FPU stuff.

Interesting... i've never really thought about 486 motherboards interleaving before... was that (at the time) IBM specific? I've certainly heard of graphics card chipsets that interleave memory, such as 'The Tseng'... not sure if (in Dos) there are many other (VLB) chipsets that can match an interleaved Tseng.

Interleaving was available on better quality 386 and 486 boards. I think there are even 286 boards that can do it.
I have five motherboards that support it. Two are VL/EISA 486 boards based on SiS 401/406 chipset. One is a pure ISA 486 based on Symphony chipset. One is a true American Megatrends 386SX motherboard (with L2 cache) that uses VLSI chipset, and the last is the Alaris 486SLC2 board based on the OPTI 82C295 chipset. It's usually a feature on higher end boards, so I'm confused as to why the opti 295 chipset supports it.

Sadly I don't own any 386DX boards that can do it. Back when I had good access to 386 parts, I focused too much energy on later generation 386 boards. Chipsets I know that support it are VLSI, C&T, SiS "Rabbit", Symphony. I suspect Micronics does as well.

I'm not really sure which 486 chipsets can do it, except that basically none of the PCI chipsets do. It's possible Intel Saturn does though.

I've had two different VLB OPTi Pentium systems too. One of them only supported 32-bit memory transfers. Neither of them supported memory interleave, which was completely ridiculous considering how much these boards would have cost when they were new. P60s were over $3000 when they first came out.

Will need to look into this a bit more... and it sounds like you have a nice collection of boards.

Begining to like more and more this interleaving business. Apologies on bringing this up onto vogons, but I've noticed on one of the other forums (graphics card related) that you said could source an ET4000/32p... untested though, is this still the case?

Cheers

Not sure about the W32P card. I can look into it.

Do you have anything interesting to trade?

BTW, I don't hate AWE32s, but I prefer not to use them since they have very noisy output and have an audible hum when connected to an integrated amplifier. I still have an AWE32 with real OPL3 actually.

AWE32's with real OPL3 are the later versions if my memory serves... like the CT3900?

Yea that would be great... a 32p or i, not sure if there's much difference? btw, do you have any opinion on the Genoa Phantom 32i?

Trade wise that's interesting... thats open to interpretation, what would be interesting to you?... is there anything specific you're looking for?

My collection seems to have a bit of everything from 286's to 5x86's, though mostly 386's. From memory... I have seem to accumulated alot of FPU's (all 40Mhz), and fast VRAM SOJ ic's.

I just uploaded another handful of photos to my web album. It appears my AWE32 is the CT3980. My old one was a CT2760.

I'm not familiar with the Genoa Phantom. I've never owned a Genoa card before. But looking at the photo, it looks like the layout and build quality are decent. Are you able to get one of those?

Do you have any spare 386DX motherboards?

Just took a better look at your collection... very interesting! You have an ATI ISA card which is 4MB!!!? I never knew this was possible... and you have a 25MHz harris!

Whilst doing my Tseng 32i research... the phantom came up in a forum with someone giving it good praise. The only two manufacturers I know so far that does the interleaved Tseng on VLB is Genoa and Diamond.

Yes I love 386 boards... I have around 5 pure (mid to late) 386 boards, and have recently aquired a few hybrids. What are you thinking in terms of requirements?

4MB cards are basically useless on ISA because the time to redraw the screen at high resolutions is too long. With 2MB you can run 1024x768 with 16-bit colour, which is way more than you will ever need on an all ISA system.

As far as I know every card with the ET4000W32i or ET4000W32p can do memory interleaving as long as 2MB is installed. I would say the Phantom is no better than a Hercules Dynamite Power, Stealth32 or STB Lightspeed. I think what's more important is to get a card with 45ns RAMs if you want to run 50MHz 0ws, and a good RAMDAC if you want to use a CRT.

I'm looking for a middle era 386 board. Probably 2/3 to full length, but needs to work at 40MHz and needs a good chipset with at least average PCB quality. As I said before, C&T, SiS (3 chip version), and VLSI are primarily what I'm after, though there may be others which are good too. I'm not interested in OPTi, PCchips, Contaq, ETEQ or MX. I don't care about DLC support as long as memory performance is good. Not interested in hybrids at all.

Thanks for all the advice... yea I was wondering if the ISA could utilise all 4MB, save for VESA.

I manged to find a Tseng 32i thankfully... though I was under the impression that the Hercules/Stealth were all higher end cards more suited to windows/GUI and even though they could do well under Dos, they would not out-perform Tseng under Dos conditions? Yea I checked the RAM specs and they are at 45ns.

I should have a board spare... I will need to have a look when I return home from work. Various chipsets... from memory mainly ALI/UMC.