VOGONS


First post, by Thermalwrong

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I have been slightly obsessed with the AWE64 recently, even going so far as to buy a SIMMCONN-revival for my AWE64 gold - only to discover that there is definitely something wrong with my AWE64 gold, it can't see any memory fitted.

So I got hold of a CT4500 and can't use the SIMMCONN-revival with it yet because it has the Gold firmware (I think?) but the memory detected, confirming my fears that it wasn't a PC issue causing the memory on the CT4390 not to read.
This card has 512KB of sample memory, provided by this 256kx16 5v 60ns EDO memory chip.

I spotted this while I was hunting for another card to test and it got me thinking, perhaps I could do similar with mine - I'd just bought a lot of 72-pin SIMMs, with these ones here being the best choice, given that they've got 1024kx16 5v 60ns EDO chips:

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The pinouts of the DRAM chips are a little different though, the original chip is a 40-pin and the DRAM chip I wanted to use is 42-pin, which appears to be more common, or the extra bus pins are necessitated by the larger address space.

Here's how it looks normally:
http://www.amoretro.de/2011/04/creative-sound … e64-ct4500.html
The pins at the bottom here are unpopulated, these are the VCC (pin 21) and GND (pin 22) on a 42-pin DRAM chip, which are pin 20 & 21 on the original 40-pin DRAM chip.

It looks like Creative designed the board to fit both types of DRAM, using the 0 ohm link resistors at R1/R2 and R8/R9 to swap between the A3/A4 address bus pins and VCC/GND on the pins that the original 512KB chip ends at.

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Simply moving the resistors from their original R2 & R9 positions to R1 & R8 ensures that VCC isn't going into the address pins:

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And now the AWE control utility and the CTCM diagnose can successfully use the 2MB sample RAM 😀

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Reply 1 of 19, by cyclone3d

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very cool!

Yamaha YMF modified setupds and drivers
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Epstein didn't kill himself

Reply 2 of 19, by Thermalwrong

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Here's the same mod on a CT4520:
1. R18 moves to R17
2. R19 moves to R16

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My AWE64 Gold is stil broken 🙁 I think it's time to move on to doing other things...

Reply 4 of 19, by Thermalwrong

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I think it's more a of an AWE64 Bronze, I'm not sure the sound quality is as good as my CT4390 was.

I'm keen to try a similar mod on a CT4380 since that has mostly the same output side as the CT4390, but I have the SimmConn working now so this memory modification is less necessary 😁

Reply 5 of 19, by appiah4

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Apologies for resurrecting a 2 year old thread, but I am planning on attempting this modification on one of my AWE64s. The thing is, I do not have a heat gun. Is it easy/possible to desolder the DRAM module with just a solder pen and solder wick? Resoldering it would be easier I presume (Just add fresh solder to the pads, add flux, place on pads and run the solder across the legs slowly should work?)

Retronautics: A digital gallery of my retro computers, hardware and projects.

Reply 6 of 19, by Tiido

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I don't think this will succeed, but since you most probably are not going to reuse the old chip just cut its pins off (I use a razor knife for such stuff when I must do it), then remove the pins one by one and solder in new chip. Though you could also heat the pin and then push it sideways until it lifts up.

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜

Reply 7 of 19, by zyga64

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Some people recomend: https://www.youtube.com/results?search_query= … uik+desoldering

1) VLSI SCAMP /286@20 /4MB /TVGA9000C /CMI8330
2) i420EX /486DX33 /16MB /Trio64V+ /AZT2316+GUS
3) i430HX /P233MMX /64MB /VirgeDX+3DFX /YMF701
4) i440BX /P II 400 /256MB /FX5500/AWE64
5) i865G /E5800 /2GB /Ti4200 /YMF724

Reply 8 of 19, by mkarcher

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appiah4 wrote on 2021-01-05, 12:01:

Is it easy/possible to desolder the DRAM module with just a solder pen and solder wick?

You can try to melt the solder on the DRAM chip and then slipping something thin and badly solderable between the pins and the PCB. I collect the thin metal sheets from the RF-based anti-theft stickers to try that method, but I didn't have a need to test it myself.

Reply 9 of 19, by appiah4

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I think clipping off the legs with a hobby sidecutter or hobby knife sounds like a sound plan, I have no use for a 512KB DRAM chip afterwards. I don't really have much faith in my ability to pull this modification off (not much if at all any SMD experience) but at least I have a lot of CT4520s to butcher..

Retronautics: A digital gallery of my retro computers, hardware and projects.

Reply 10 of 19, by Tiido

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Cutters will probably damage pads on the PCB since the force it excerts on the pin has only up or down to go and neither direction works, a knife straight down will work lot better as it will push pin sideways away from the chip where it can go.

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜

Reply 11 of 19, by Thermalwrong

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I vote for the thin unsolderable object in between as you heat up the solder, usually I'd use a craft knife for this method since it'll usually be oiled and sink heat quickly enough that solder won't stick.

Reply 12 of 19, by maxtherabbit

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I vote for "buy a damn hit air tool"

The amount of effort people exert in this hobby to do things the wrong way baffles me. You can get cheap chinese tools if budget is a concern

Reply 13 of 19, by appiah4

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maxtherabbit wrote on 2021-01-06, 03:12:

I vote for "buy a damn hit air tool"

The amount of effort people exert in this hobby to do things the wrong way baffles me. You can get cheap chinese tools if budget is a concern

Calm down amigo. I dont want to invest into anythşng I know will not get a third or even a second use..

Retronautics: A digital gallery of my retro computers, hardware and projects.

Reply 14 of 19, by Ozzuneoj

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appiah4 wrote on 2021-01-06, 11:32:
maxtherabbit wrote on 2021-01-06, 03:12:

I vote for "buy a damn hit air tool"

The amount of effort people exert in this hobby to do things the wrong way baffles me. You can get cheap chinese tools if budget is a concern

Calm down amigo. I dont want to invest into anythşng I know will not get a third or even a second use..

I thought this too. Now I have a Hakko digital soldering iron, a (generic) vacuum desoldering station and a digital controlled hot air station. 🤣

Anyway, for what it's worth, I bought one of these (identical looking but a different brand) a couple years ago and it is a complete game changer for almost any soldering project:
https://www.amazon.com/VIVOHOME-Rework-Statio … 09948649&sr=8-8

Working with SMD components isn't easy, but this makes things possible that simply weren't before. Simply being able to heat up the board quickly and precisely makes even through-hole soldering of multi-layer boards 10 times easier. This was the last tool I purchased for working on old PCs... it should have been the second (after a good digital soldering iron). For SMD, I'd say it would be the first.

EDIT: Holy cow, just realized I was saying this to appiah with 6000 posts on the board. Kudos to you if you have managed to go this long without buying lots of neat tools to work on old PCs. 😀

Time Machine = FIC PA-2013 2.1 - K6-2 500 - 256MB PC-100 - TNT2 Pro 16MB AGP - Labway Yamaha YMF719-E - Midiman MM401

Reply 15 of 19, by appiah4

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Ozzuneoj wrote on 2021-01-06, 16:02:
I thought this too. Now I have a Hakko digital soldering iron, a (generic) vacuum desoldering station and a digital controlled h […]
Show full quote

I thought this too. Now I have a Hakko digital soldering iron, a (generic) vacuum desoldering station and a digital controlled hot air station. 🤣

Anyway, for what it's worth, I bought one of these (identical looking but a different brand) a couple years ago and it is a complete game changer for almost any soldering project:
https://www.amazon.com/VIVOHOME-Rework-Statio … 09948649&sr=8-8

Working with SMD components isn't easy, but this makes things possible that simply weren't before. Simply being able to heat up the board quickly and precisely makes even through-hole soldering of multi-layer boards 10 times easier. This was the last tool I purchased for working on old PCs... it should have been the second (after a good digital soldering iron). For SMD, I'd say it would be the first.

EDIT: Holy cow, just realized I was saying this to appiah with 6000 posts on the board. Kudos to you if you have managed to go this long without buying lots of neat tools to work on old PCs. 😀

🤣 I didn't realize I had so many posts myself to be honest. Well, I've done quite a bit of repairs and some DIY projects like the Adlib and Snark Barker but the tools I use are fairly simple - a fixed 30W soldering iron pen with no temperature control, some solder braid and a solder pump. It worked so far, except the one time I ended up destroying a 486 motherboard while desoldering a KBC.. But yes, I probably do need a better soldering station for sure, at the very least.

The issue is, I don't have the room to keep it. As it is, most of my stuff is packed up in a small box, and I unpack it on the dining table every night after everyone else goes to sleep, and I have to get it all packed up again before morning. This makes buying things like a soldering station or a hot air gun particularly troublesome, especially I have other hobbies that share the same fate (my dremel tools, paints and brushes for miniature painting, my guitar and recording setup for music etc.) Once you have kids, your life is gone 😁

Retronautics: A digital gallery of my retro computers, hardware and projects.

Reply 16 of 19, by detalite

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I sugest a cheap hot air model 858D. It's around $40 and works a treat. Very universal tool. You can even dry your hair, if you are brave enough.

Once you have kids, your life is gone

Location: Sea of Sorrows

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EDIT:
I think that using desoldering wick on old solder, then put on ChipQuick and hair dryer at the end will be sufficient to desolder memory chip.

Reply 17 of 19, by Ozzuneoj

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appiah4 wrote on 2021-01-07, 06:24:

The issue is, I don't have the room to keep it. As it is, most of my stuff is packed up in a small box, and I unpack it on the dining table every night after everyone else goes to sleep, and I have to get it all packed up again before morning. This makes buying things like a soldering station or a hot air gun particularly troublesome, especially I have other hobbies that share the same fate (my dremel tools, paints and brushes for miniature painting, my guitar and recording setup for music etc.) Once you have kids, your life is gone 😁

I see. I guess I should be very glad that I have space to work then. I have a wife and child, but we bought a hundred year old house because it had some extra rooms, and I get an office... but then I work from home part of the year doing PC repair and selling stuff online, so it was kind of necessary. The problem is that it's very easy to horde too much stuff. I think I've been doing okay selling or giving away a lot of stuff, but... I still have way more than I need. If I were a less reasonable person I would have a storage unit somewhere full of CRT monitors, just to keep for the day when they're worth their weight in gold. I already have... oh my... at least ten? How did that happen. 😮

Time Machine = FIC PA-2013 2.1 - K6-2 500 - 256MB PC-100 - TNT2 Pro 16MB AGP - Labway Yamaha YMF719-E - Midiman MM401

Reply 19 of 19, by Thermalwrong

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I think that's most likely what started all of this. Shortly after that date, I found a card with the same mod up on ebay and looked into how it worked. I'm not sure that Youtube was auto translating titles like it does now.