VOGONS


First post, by dkarguth

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I bought some SIMM sockets and 4 1 MB sticks of SIMM memory to max out my 286 motherboard. Why you may ask? Because why not?
Anyway, When I looked it up, most SIPP sockets on motherboards that have them are labeled with pin 1 on one side of the socket. Mine has no labeling. Does anyone know the correct orientation based upon this picture? I'll also include the model of my motherboard. Or perhaps there's a pin that I can ohm to ground to determine the orientation? Any help here will be appreciated.

Memory Sockets:
9zyFZkK.jpg

SIMM memory:
TsKjsC4.jpg

Motherboard Type:
https://stason.org/TULARC/pc/motherboards/U/U … -HAM-12-TI.html

Last edited by dkarguth on 2019-02-05, 01:41. Edited 1 time in total.

"And remember, this fix is only temporary, unless it works." -Red Green

Reply 1 of 18, by dkarguth

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I did find a pinout, but annoyingly, the ground and VCC pins are exactly symmetrical. That means I can't use that method for finding the orientation.

"And remember, this fix is only temporary, unless it works." -Red Green

Reply 2 of 18, by retardware

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Aren't the module's pinouts the same?
Afaiu SIPP were actually SIMM with pins attached, for enabling socket-free permanent soldering.

Look at the board, it has already both holes for the SIMM socket fasteners.
But to be safe, consult manuals and datasheets and verify that pinouts are actually identical.

Reply 3 of 18, by dkarguth

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The pinouts are the same. The thing I'm not sure about is which way to put the RAM in. Usually SIPP sockets have one side of the socket that is marked with a '1' or a '30' to indicate which way you're supposed to insert the RAM, but mine has no such marking. My motherboard is of a somewhat obscure variant, so I can't find any information about it other than the link that I posted at the end of my comment.

"And remember, this fix is only temporary, unless it works." -Red Green

Reply 4 of 18, by retardware

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Look at the datasheet of the RAM chips on the board. They should share some signals, addresses, WE, for example.
From this you could find out where to paint the pin 1 dot on the mobo.

Reply 5 of 18, by quicknick

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dkarguth wrote:

I did find a pinout, but annoyingly, the ground and VCC pins are exactly symmetrical. That means I can't use that method for finding the orientation.

Once I got a board that had all the SIPPs installed backwards (non-booting, sold as defective). Worked perfectly after turning them around. So that's why they are symmetrical. Nothing burns up when installed backwards, it just doesn't work.

Edit: on a closer look, I think pin 1 goes toward the edge of the board. If you look carefully, it is marked ("boxed") somehow...

Reply 6 of 18, by dkarguth

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OK, I guess I'll just take the gamble and install them in that orientation. I scoured the pinout and found nothing that would short/toast if I plugged it in backwards, so I'll just try it. Do I have to take out the DIP memory to be able to use the SIPP sockets?

"And remember, this fix is only temporary, unless it works." -Red Green

Reply 9 of 18, by retardware

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dkarguth wrote:

Do I have to take out the DIP memory to be able to use the SIPP sockets?

Doesn't the manual say that the DIP memory is Bank 0, and the SIPP slota bank 1, 2 and 3?

Reply 10 of 18, by dkarguth

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Yeah, I just like to double check about things that I don't know. It's always nice to have the peace of mind that you're not about to toast something. 🤣

Mission success! Thanks for the help, everyone!

IMG16BIl.jpg
KuOEPVcl.jpg

"And remember, this fix is only temporary, unless it works." -Red Green

Reply 11 of 18, by CrossBow777

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I know you have this figured out already, but wanted to chime in that there is nothing wrong with 5mb of RAM on your system. I did the same thing to my Memorex/Telex 286-16 I had back in the late 80s early 90s. Cool thing about that 286 was that it had a custom driver that came with it that enabled me to load up expanded memory on it?! Only 286 I've found with this ability. So I used to load up like and extra 1024 of extended and load up the emm driver to put the rest to expanded memory. Every game that supported expanded ram would see it and use it. It was really cool to see Wing Commander with all the animations in the cockpit on my system back then. I should have kept that 286 but I believe it is a rust bucket in my mother's garage these days.

g883j7-2.png
Midi Modules: MT-32 (OLD), MT-200, MT-300, MT-90S, MT-90U, SD-20

Reply 12 of 18, by alvaro84

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CrossBow777 wrote:

Cool thing about that 286 was that it had a custom driver that came with it that enabled me to load up expanded memory on it?! Only 286 I've found with this ability.

I have a Hedaka (PCChips) HED988 and an Octek Fox II with Headland HT12 chipset, both have EMS drivers that I downloaded right from the Vogons library. It's quite nice to see EMS in a 286, especially with 4MiB that would have been a ludicrous amount in the 286 days. GLX player can use it to play mods and s3ms that don't fit in the low 640k 😀

But I couldn't get 5MiB working, at least not with the Octek. If I stick in 1MiB SIMMs it forgets the DIP memory so I removed it. I can use 256kiB SIMMs together with the DIPs to get 2MB in a VLSI board, though.

The Hedaka can, on the other hand, handle 16MiB - with caveats. It takes some entering and exiting to/from setup to get it working until the next reset. But then it's a 286 with its address space full of delicious RAM 😁

Last edited by alvaro84 on 2019-02-05, 19:52. Edited 1 time in total.

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May God have mercy on our dirty little hearts

Reply 13 of 18, by CrossBow777

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Yeah the memorex/telex 286 I had used a Headland chipset in it. But the actual CPU was an AMD. I know because more than once (I was stupid and young...) I could open the hatch that contained the actual die and remove it and did several times to look at it. It always still worked afterwards. Though I suspect my grimy fingers back then likely would have made that CPU die a corrosive mess today. But yes, many of my friends back then were pretty jealous that my 286 could run with the 386 boys with ease with the expanded memory and other upgrades I put into it over the years. However, Window 3.11 wasn't stupid and would still only let me run in real mode on that system.

g883j7-2.png
Midi Modules: MT-32 (OLD), MT-200, MT-300, MT-90S, MT-90U, SD-20

Reply 14 of 18, by kool kitty89

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alvaro84 wrote on 2019-02-05, 14:37:

I have a Hedaka (PCChips) HED988 and an Octek Fox II with Headland HT12 chipset, both have EMS drivers that I downloaded right from the Vogons library. It's quite nice to see EMS in a 286, especially with 4MiB that would have been a ludicrous amount in the 286 days. GLX player can use it to play mods and s3ms that don't fit in the low 640k 😀

The Hedaka can, on the other hand, handle 16MiB - with caveats. It takes some entering and exiting to/from setup to get it working until the next reset. But then it's a 286 with its address space full of delicious RAM 😁

The D60 based boards I've tried (and the extra BIOSs I've also tried) from the 988, M205, and M209 all also seem to do EMS, XMS, and shadow RAM configuration in the BIOS, not through drivers in DOS. The drivers are needed to enable EMS in DOS and to configure RAM disks, disk cache, and/or print spool buffers. (at least that's what the PC Chips driver utility has that I got on a 5.25" disk ... haven't tried the vogons drivers, but there's a nice, apparently new old stock supply of drivers + manuals for the M209 on ebay for cheap)

I'll have to try my 988 with 16 MB at some point. I finally found some SIMM sockets at a reasonable price and they're grouped in pairs that should match the SIPP hole allignment here, too, so that could be neat.

And 4 MB isn't that crazy for boards that were new in 1990 or 1991 and upgraded a year or two later. (1992 or very early 1993 was the sweet spot there for 1MB SIMM/SIPP RAM upgrades as a major epoxy factory fire caused massive shortages and price increases for new RAM in '93; and the availability of discounted/available 256kB SIMMs and SIPPs isn't great for boards with just 4 sockets that usually couldn't use DIPPs at the same time and typically already had 640k or 1MB installed, though there's the SIMM saver/extender module approach if banks are installed with sufficient spacing or side-by side and not back to front)

But, the 988 is great as it ALSO has 2MB worth of DIPP sockets, so upgrading is much more flexible than most SIPP and SIMM based boards, and 2MB is mighty useful for games and other 16-bit software from that period, though 4 MB gets you a bit more breathing room for Windows 3.x and some demanding EMS capable games (or games that need EMS and enough base memory to require DOS loaded high in XMS ... though QRAM style real-mode UMA/EMS-enabled limulators might also work around that with no XMS)

So the 988 has the best of both worlds of the PC Chips M205 and M209, aside from being a bigger board. (I think the full baby AT board dimensions)

And from a modern-retro standpoing, the 2MB of DIPS makes it convenient when 60 ns 256kx4-bit DIPS are plentiful on ebay, at least if you want to try overclocking. (the D60 seems to do fine at 20 MHz with 80 ns RAM or better, might do 22-24 with 70, but doesn't seem to do 25+ without 60) And DIP ram of any speed tends to be more common than SIPP modules or SIMM sockets anyway.

That and a 286 20 or 25 with a low wait state VGA card, sound blaster, and CD-ROM drive might be good for a few real-mode RPG and graphic adventure games that need more than 2MB of base+EMS memory. (and some 3D games, but given it's marginal for X-Wing, I don't think Tie Fighter would fare very well ... though the poly-counts aren't much higher at minimum detail and then there's X-Wing CD that lacks the polygonal HUD and drops to flat shaded rendering at the lowest detail settings rather than the dithered gouraud shading ... I should try that actually, and having all those digital sfx avoids weird, card/module dependent general midi sound effects like the floppy disk version has)

CrossBow777 wrote on 2019-02-05, 15:24:

Yeah the memorex/telex 286 I had used a Headland chipset in it. But the actual CPU was an AMD. I know because more than once (I was stupid and young...) I could open the hatch that contained the actual die and remove it and did several times to look at it. It always still worked afterwards. Though I suspect my grimy fingers back then likely would have made that CPU die a corrosive mess today.

I think you may have had a CLCC (ceramic leadless chip carrier) packaged Am286 in there. Those tend to have clamped-on heatsinks/heatspreaders that also serve to clip the CPU in place (it just sits there sort of like modern LGA sockets; the CPU leads work like lands)

I'd initially thought some of these were just typical leaded chip carrier sockets with clipped-on heatsinks for added reliability of the hot, NMOS 286 chips, but I now think all of the ones I've seen around are the leadless ceramic type ones.

So you weren't handling a bare die and probably didn't do much damage to those gold-plated leads (mechanical scratching would probably worse than corrosive grime). The metal die cover on the underside does take up a lot of the surface real estate, though. (it's weird to handle a wafer thin ceramic package like that with no pins or bumpy leads on it)

I bet that hatch looked something like this one on a Suntac based board (which appears to have a 10 MHz AMD 286 factory overclocked to 12).

The downside for me here is I'd have to solder in a normal PLCC socket if I wanted to swap in a fast/overclockable CMOS chip, but this is super cool intact as-is. I could put a 12.5 MHz CLCC in there and try pushing it to 16 MHz or so.

And with a tiny dab of zinc oxide based thermal grease applied, I closed that back up ... and it seems to conduct quite well. (warms up fast, but seems to do its job as the aluminum fins don't top out quite as hot as NMOS PLCC 286s I've had running ... at least going by the how-close-to-burnt-is-my-finger test)

This Suntac chipset is supposed to support EMS as well. (though might not support XMS and EMS at the same time) And this board supports up to 4 MB via DIP chips (using 36 1Mx1-bit chips ... and I've got an old DEC VME system RAM board with 4MB of 70 ns CMOS DRAM I could pull and re-use here: Dad had that and was going to toss it a couple years ago, he had a whole VME rack + system unit he got surplus from work somewhere around 1992, but the rest of the system boards got recycled around 2002, around the same time as he junked his big AT tower case I think ... and maybe the B&W VGA monitor from the first computer build he did for me around '93, but that might've been later: he didn't do that without asking me first, mind you).

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Reply 15 of 18, by Deksor

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Another indicator to find the orientation : the holes on the sides of the connector, if you pay close attention, you'll see that one is bigger than the other, so if you solder in the SIMM slot, it will go only in one way.

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 16 of 18, by pentiumspeed

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Note the outlined SIPP silkscreen print on the motherboard, one end is boxed around the pin 1 of this SIPP connector.

Cheers,

Great Northern aka Canada.

Reply 17 of 18, by kool kitty89

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Sometimes the SIPP sockets can be soldered in backwards, indicating the opposite direction they should.

The MB-1212C I have has the pin 30 locations silkscreened onboard in the correct location, but the sockets (2 dual SIPP socket-modules) have the indent/cutout placed on the wrong side (on the Pin 30 side rather than Pin 1).

My Hedaka 988 has no useful board markings, but similar SIPP sockets that are correctly oriented.

Stason appears to have the correct orientation listed for the 1212C and sockets that point the right direction.
https://stason.org/TULARC/pc/motherboards/B/B … N-286-MB-2.html

My board has the reverse of that.

As was discovered last year earlier in this thread, SIPP (and 30 pin SIMM) pinouts are arranged such that the power and ground lines are symmetrical and other signals are generally non-harmful if installed backwards, so trial and error works OK. (though given how fragile SIPP pins can be, especially formerly-bent ones, that task isn't fun either if you screw up)

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Reply 18 of 18, by ajacocks

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UPDATE: Solved...I found the fact that, unlike some other 286 boards, you need to remove the DIPPs, before it will recognize the SIPP sockets. I really need to change those sockets out for SIMMs.

The clue was here:
VLSI SCAMP - native PS2 mouse

ORIGINAL POST:
I have a similar board, which has 1MB of RAM, in DIPs and 4 empty SIPP sockets. You can see the board, here:

https://commons.wikimedia.org/wiki/File:286_B … oard_layout.jpg

I’ve got 4x NEC 4MBx9 SIPP modules, that I’m trying to install on the board, and the best that I can accomplish is to reduce the amount of RAM recognized to 512k. Unfortunately, I don’t have a motherboard manual, so I’m not sure what I need to do, to get the RAM recognized.

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Does anyone have a similar board? It seems that these tiny 6-slot boards were pretty common, towards the end of the run for the 286.

Thanks!
- Alex