AST time again...

I want to give the AST 2 MB of RAM instead of the installed 1MB.
There is a slight problem... I cant print money...
The system uses 1x256kbit chips as RAM. 512kb of RAM use !!18!! of these freakin chips...
And because i need 36 of them, the retro resellers decided they cost 3 (to 12) Euros EACH!!!

So... I had to get creative.
I have a 286 donor board from the scrap where all socketed chips are missing and with battery damage.
And it uses the right RAM chips for my AST... Easy decision.
It took me 5 hours to desolder 18 Chips, clean them, test them and find out that 16 of the 18 chips work perfectly fine!
Just 2 broken ones. NEAT!

Now i need just 20 instead of 36. And because i have time i will see where i can find cheap ones.

Donor:

Cleaned chips:

AST FastRAM card i have to fill (with the 2 broken chips on top):

CheckIT is happy with my rescued RAM:

Finally i made a parts bag with a boot disk, the 2 broken ics, the 16 working ics and the case screws.

Tried remaking my own B52-MMX... using an Katmai 500 cartridge and a SL2W7 🤣

And the custom SL35E is done... for now.

The other CPU is a SL2HC Klamath, no idea if it's locked or not.

GigAHerZ wrote on 2023-09-22, 20:00:

You should not run it naked like i did on test run!

Does this mean that you are all white except for a tanned strip?
Sunscreen is the answer!

On a serious note, this is an interesting project. Might come in handy sometime.

Finished replacing some caps on a Tyan S2460. I used spares smaller than original, may buy exact matches if I decide to use it for some project in the future.
Cpu POSTs on both sockets, no order required. Had to try 3 AGP cards to make it go to screen, otherwise silent POST. Probably doesn't work with universal cards.

Recently acquired this Roland SCC-1. While the card is detected and MIDI output works, it does not produce any audio output.

Initial examination did reveal a cracked resistor (R2), but that on the MIDI input circuit, so not relevant to audio. Other than being dirty, there is no other physical damage.

Testing for shorts didn't reveal any issues. All pins on the various ICs are also firmly soldered.

I suppose the next step will be to probe the DAC (NEC D6376) and see if it's getting proper voltage, and input from the main Roland sound chip. I'm hoping it's just a faulty DAC, as that would be an easy and inexpensive repair.

I want to save this Medion (Lifetec) MT4 Pentium 3 Tower.

Of course the caps are exploded. I didnt expect anything else.

But...

There is an unpopulated ISA slot and a SB_Link header between the pci slots...
Do you think they will work when i solder on the missing slot / header ?
There are some components missing on the lower left corner, but i dont know if they are even related to the isa slot or sb_link connector... but most of the traces from the ISA slot go directly into the chipset...

Completed this very portable Windows 98 in an Asus Eee PC 1201K netbook with SiS chipset and an Athlon 1 Ghz.

Everything has compatible drivers with the exception of the Realtek AC'97 sound card. There is the SBEMU project that made it kinda work but only in a few games.

So decided to go the hard way. I hijacked an USB port and the speaker connection, and routed them to a cheap USB "external" sound card (from which I desoldered the usb and jack plugs).
And it works perfectly. I have sound effects and music also in DOS games thanks to the SB16\General Midi emulation in Windows DOS mode!

There is only one thing a bothers me a little but only in games with fixed resolutions, and of course is the widescreen aspect ratio... is there something I can do about it?

DerBaum wrote on 2023-09-23, 23:26:

I want to save this Medion (Lifetec) MT4 Pentium 3 Tower. 2023-09-23 23.14.48.jpg […]
Show full quote

I want to save this Medion (Lifetec) MT4 Pentium 3 Tower.
2023-09-23 23.14.48.jpg

Of course the caps are exploded. I didnt expect anything else.
2023-09-23 23.31.35.jpg2023-09-23 23.31.57.jpg

But...
2023-09-23 23.30.59.jpg
There is an unpopulated ISA slot and a SB_Link header between the pci slots...
Do you think they will work when i solder on the missing slot / header ?
There are some components missing on the lower left corner, but i dont know if they are even related to the isa slot or sb_link connector... but most of the traces from the ISA slot go directly into the chipset...

I have no answer for this question BUT the board is manufactured by MSI so you you might want to visually compare it to the MS-6168 and other highly similar MSI 440ZX boards with an ISA connector.

A001 wrote on 2023-09-24, 13:27:

I have no answer for this question BUT the board is manufactured by MSI so you you might want to visually compare it to the MS-6168 and other highly similar MSI 440ZX boards with an ISA connector.

Thanks. I think i will just try to fit the isa slot and the sb_link connector and see what happens 😁
but first new caps to see if it even works again. 😀

DerBaum wrote on 2023-09-24, 14:24:

A001 wrote on 2023-09-24, 13:27:

I have no answer for this question BUT the board is manufactured by MSI so you you might want to visually compare it to the MS-6168 and other highly similar MSI 440ZX boards with an ISA connector.

Thanks. I think i will just try to fit the isa slot and the sb_link connector and see what happens 😁
but first new caps to see if it even works again. 😀

Looks like this one doesn't it? https://theretroweb.com/motherboards/s/medion-medion-9901
It certainly looks like a very close relative of the MS6168 - I was taking a look at mine again today and the power section on your Medion board is just about the same.
Found the MOSFETs are both broken on my MS6168 - the CEB703AL, and found I messed up some capacitor connections when I recapped the board, that's fixed now at least.

Also I've been doing some lazy amplifier bypass mods to improve the sound quality on these ALS100/ALS200 cards:

mrfusion92 wrote on 2023-09-24, 13:10:

I hijacked an USB port and the speaker connection, and routed them to a cheap USB "external" sound card (from which I desoldered the usb and jack plugs).

PXL_20230924_130200189.MP.jpg

😮 can you please elaborate on exactly what you did and what is this external sound card?

Joakim wrote on 2023-09-24, 18:27:

😮 can you please elaborate on exactly what you did and what is this external sound card?

Just permanently attached a USB sound card inside the netbook. I can't use anymore that USB port but there is another one.

It is a 5€ no-brand USB sound card from amazon.

Decided to move my test bench upstairs to my office from the basement, where it's much more comfy. 😀

Drilled a gromet into my desk for routing cables to my under-desk-mounted power strip.

Starting with some "newer" AGP cards using my newly acquired ASRock 4coreDual-VSTA running Win98SE with an Intel Core2Extreme QX6700 (2.66Ghz) for starters.

Gonna give a go at recapping ms-5191 motherboard. Is OEM socket 7. Bought some bits online. Never done this before. Motherboard full of tayeh and Jpcon caps which I've read are sh*te

DerBaum wrote on 2023-09-23, 23:26:

I want to save this Medion (Lifetec) MT4 Pentium 3 Tower. 2023-09-23 23.14.48.jpg […]
Show full quote

I want to save this Medion (Lifetec) MT4 Pentium 3 Tower.
2023-09-23 23.14.48.jpg

Of course the caps are exploded. I didnt expect anything else.
2023-09-23 23.31.35.jpg2023-09-23 23.31.57.jpg

But...
2023-09-23 23.30.59.jpg
There is an unpopulated ISA slot and a SB_Link header between the pci slots...
Do you think they will work when i solder on the missing slot / header ?
There are some components missing on the lower left corner, but i dont know if they are even related to the isa slot or sb_link connector... but most of the traces from the ISA slot go directly into the chipset...

Lol, what are the odds

Brought to life 2 motherboards:
* ASRock 775i65G
* Asus P2L-B

with this little thingy:

stef80 wrote on 2023-09-25, 06:58:

Brought to life 2 motherboards: * ASRock 775i65G * Asus P2L-B […]
Show full quote

Brought to life 2 motherboards:
* ASRock 775i65G
* Asus P2L-B

with this little thingy: 20230924_184104.jpg

XCegu T48 is a fine programmer! I ordered few more adapters for it and I especially need PLCC32 for BIOS stuff.

What I really like about it is the great support for different chips. VPP voltage goes up to 25V and I’ve succesfully programmed couple of older DIP eproms which require 21V. Older T866s capped at 18V, many knock-offs can’t do even that so without modifying the programmer, you can’t program those.

These T48s just work. Only minor issue is that I’ve noticed that not all chips have correct values in XGPro software, so you may need to dig up the datasheets for the chips, if something isn’t working as should. For example, I was unable to write one of those eproms first, because in the software the VPP was only 14V and not enough to successfully write to the chip.

I took the package with all PLCC adapters. It works great. Erasing/blanking/flashing is unusually fast comparing to regular motherboard flash from floppy 😀.
Unfortunately, it's not supported via "minipro" on Linux., unlike older TL866A, CS or II Pro.
TL866II Pro is the only one supported by both: latest XGecu software and minipro.

mrfusion92 wrote on 2023-09-24, 19:30:

Just permanently attached a USB sound card inside the netbook. I can't use anymore that USB port but there is another one. PXL_2 […]
Show full quote

Joakim wrote on 2023-09-24, 18:27:

😮 can you please elaborate on exactly what you did and what is this external sound card?

Just permanently attached a USB sound card inside the netbook. I can't use anymore that USB port but there is another one.
PXL_20230924_082428923.jpg
It is a 5€ no-brand USB sound card from amazon.
51sT+fZemkL._AC_SL1000_.jpg

Ok thanks, but I had no idea there are usb based sound cards that support dos? 😮