stamasd wrote:

Yeah, the board in the last thread linked is the exact same one I have (I'm the one who bought it from CPUshack). […]
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Yeah, the board in the last thread linked is the exact same one I have (I'm the one who bought it from CPUshack).

Ah I see now https://th99.bl4ckb0x.de/m/A-B/30905.htm linked from above is very close to this board. Looks like it was listed in TH99 under 486 boards not 386. 😀

I'll have to see if something changes when I hook a battery to J1.

Now I really want to get this board going.

(edit) I hooked up an external battery, which was weird because J1 is located in a very awkward position. Still no go. I tried a different video card, no change. Eventually I pulled out an ISA diagnostic card, which I don't trust too much because it usually gives weird and poorly reproducible codes. This time it gave me a BIOS code of "no" i.e. no BIOS code at all. According to the manual that may mean the CPU is bad. I don't think I have any spare 386DX25 CPUs available to test, but I'll look through my stash and see if I find one.

But... would the keyboard LEDs flash once if the CPU wasn't working? Because they do. 😕

Maybe the original owner fried the CPU or motherboard when he put a 286 in the FPU socket. 😢

I never really thought to buy this Mediavision Pro graphics card, but $12 with free shipping seemed like a pretty good deal to just try it out and see what it's all about:

http://www.ebay.com/itm/Media-Vision-ProGraph … wYAAOSwImRYWBXt

^ bought the same card earlier this month for ~$40.
It's a nice piece of hardware and history as the future management team of 3Dfx participated heavily in its design.

I saw that while eating my lunch (late). Its interesting that it has two graphic chips as one is a windows accelerator, the other for DOS. Love that its by Media Vision though!

I guess it even deserves its own thread here.
Meanwhile I'll post some links to back up my previous post:
https://www.youtube.com/watch?v=3MghYhf-GhU&t=1580s - 3dfx Oral History Panel with Ross Smith, Scott Sellers, Gary Tarolli, and Gordon Campbell
http://archive.computerhistory.org/resources/ … 4-05-01-acc.pdf - same but in PDF
http://www.vcfed.org/forum/showthread.php?276 … -Graphics-1280p - a very interesting thread with some valuable insight
and bonus link for all of you who might be interested in getting one NIB (however without a retail box as it seems): http://cfusion.com/parts/index/NEW_MEDIA_VISI … PHICS_1024.html

Picked up this, EMU SoundEngine (aka the refined/last version of the WaveBlaster daughter board in MIDI module format). Been after one for a while. Needs some cleaning up and small amount of attention before it goes into the stack; I was hoping for a later version but its an early version. Main PCB is a Rev B, and the chip date codes are all over the place, mid/late 93, early/mid 94. Im not sure but I think the main EMU/OKI chip is dated 1995, which is odd.

So it might actually be a later version than I thought, given other photos I find on the net of the main chip is dated 93 and all support chips have early 93 dates.

All other photos I find of this (including WaveBlaster boards) have IC376 Rev A or B... mine is IC404 Rev A...

Originally it was on ebay for insane crazy price and it got no bids, after that I messaged seller and got it for an awesome song 😜

It has samples from the Proteus line?

Yes. Its a GM module but it has two modes, GM and a Proteus mode. It also has a DSP for reverb and chorus which waveblaster lacks.

I need to find/create a midi to just send the sysex message to reset it into midi or proteus mode. Its soundfont is 4M in size

More bad news about the AMI 386-XT motherboard. I tried 2 other CPUs in it: a Cyrix 486DLC-33 and an AMD 386DX-40, both of which should have no trouble working at this board's speed of 25MHz. The board doesn't POST with any of those.

Moreover, I looked up the extended codes that the ISA POST card is spitting out, and literally the manual says at the chapter for those codes "don't bother trying to repair the motherboard" 🙁

I have really bad luck with 386DX motherboards. I have several working 386SX ones, but this will be the 3rd DX motherboard that is DOA. 😵

Codes?

Maybe it's says not to bother repairing the broad because the problem is elsewhere? Wishful thinking on my end.

No, it says that after a list of problems that those error codes mean, like bad reset circuit, etc. Essentially, the motherboard has so many problems that it's not worth trying to repair it.

stamasd wrote:

More bad news about the AMI 386-XT motherboard. I tried 2 other CPUs in it: a Cyrix 486DLC-33 and an AMD 386DX-40, both of which should have no trouble working at this board's speed of 25MHz. The board doesn't POST with any of those.

Moreover, I looked up the extended codes that the ISA POST card is spitting out, and literally the manual says at the chapter for those codes "don't bother trying to repair the motherboard" 🙁

I have really bad luck with 386DX motherboards. I have several working 386SX ones, but this will be the 3rd DX motherboard that is DOA. 😵

I had a similar experience with TI486SXL in a SiS based 33MHz 386 board. I suspect it might be because there is no support for "hidden refresh".

Do you have a picture of your AMI 386=XT? Is that the same as the Mark III?
I have an AMI 386SX XT (series 20). The Cyrix 486SRx2 chip works on this board.

The picture is on the previous page of this thread.

I'm working on perfecting the specs of my 3dfx Voodoo2 build, and finally found the correct drives for what I'm after.

The build is basically a Summer/Fall 1998 spec'd system, so the Maxtor DiamondMax Plus 2500 (91000D8) will be the master. I really liked the reviews the drive got at the time, as one of the first 7,200 RPM drives.

I got the IBM Deskstar 22GXP DJNA-372200 with the idea that it would of been a 1 year later upgrade to hold all the newer larger games. It was one of the largest 7,200 RPMs at the time.

stamasd wrote:

The picture is on the previous page of this thread.

Yep, it says "Mark III" on the BIOS chip. This board was pretty novel in that you could upgrade it to a 486 with a special CPU card. It's definitely a classic worth keeping, even though it doesn't work with your chips of choice.

Really retro. Not full systems, only chips. Got an almost full MCS-4 set (4004 and supporting chips) and a MCS-40 set as well (4040 and supporting chips).

What games can I play on those? 😁

I finally found it: a loose Roland MCB-1 for my LAPC-I at "reasonable" price (~50€).

Now my Roland MIDI collection is fully satisfied (for now at least). I have LAPC-I, MT-32, SC-55 MkII and SCP-55. I use LAPC-I for LA synth in my main retro 486 and now I can connect my SC-55 to it if I need General Midi. With my retro laptops I use SCP-55 and I can hook my MT-32 to the SCP-55 if I need LA synth. 😎

Nice! Any chance of documenting the internals? Unlike the MPU-401, I suspect the MCB-1 is quite simple. It might be possible to clone it.

^ I have the LAPC-I service manual and it covers the MCB-1 as well:

Standard buffer gates and an optocoupler. It'd be a good, straightforward project for anyone interested.