Uncreative Labs

Joined: 27 Jan 2007 Posts: 274 Location: USA

define dead... as in harddrive crash, computer wont detect drive or what?

Joined: 22 Apr 2007 Posts: 264 Location: Ohio/USA

Floppy light comes on, but cannot read a perfectly good disk so it dumps me to ROM basic on boot (cannot boot from the installed HDs because I just installed a battery and none of the cards are setup, and I need a floppy to set them up).

Joined: 27 Jan 2007 Posts: 274 Location: USA

oh were talking about floppies, well it seems the drives read/write heads are out of alinement. its posible to fix that

Joined: 02 Oct 2004 Posts: 594 Location: Western NC

The best resources for PS/2's I've found are:

http://members.tripod.com/~ps2page/ps2faq.txt

http://www.computercraft.com/docs/160.shtml
(though you kinda have to ignore the "local political stuff" on the right banner)

http://www.mcamafia.de/mcapage0/mcaindex.htm

There used to be a page specifically for repair of the Model 80 FDD, but a Google search doesn't seem to turn it up. I've got it printed out somewhere (probably in the documentation I have for the Model 80), but I seem to recall that the most common failure was due something like a couple of "foam-type" pads over top of the read-head of the floppy. I remember taking mine apart, refitting the pads (the glue had shifted the pads slightly--probably due to heat or age), cleaning the head with alcohol, and presto---working floppy drive! Never had a problem with it up until the time the battery croaked...

Sadly, this page used to be one of the best "links" pages around, but virtually nothing there is still around:

http://www.walshcomptech.com/ps2/complinks.htm

Somewhere, there also used to be something like an "IBM's Insider" page which discussed (at length) the "goings-on" inside IBM during the PS/2 era. It was extremely intriguing, and read somewhat like a Tom Clancy novel. It also discussed the "Gang of 9" which developed the EISA bus. What IBM didn't realize (and big businesses still don't understand) is that a proprietary design is doomed to failure. The point of the page was that IBM had every indication of this, and still "force-fed" the MCA architecture to it's customers.

Also while searching, I came across this little jewel (for those who like their books in .pdf and .wmv format):

http://www.informit.com/content/downloads/que/upgrading/

I always liked Muller's books, but haven't been able to justify buying one lately since most of the stuff I deal with is covered in earlier versions...

Joined: 22 Apr 2007 Posts: 264 Location: Ohio/USA

I took mine apart, the foam pad was still intact and in place, the head seems to move when it should. I asume the capacitors in the design are going bad.

Anybody know of a cheap source for DS1287 RTC chips?

Joined: 02 Oct 2004 Posts: 594 Location: Western NC

Froogle (actually now Google Products) is your friend:

http://www.google.com/products?q=DS1287&oe=utf-8&scoring=p

This page also may be of some use:

http://www.maxim-ic.com/appnotes.cfm/an_pk/503

Maxim used to be pretty good about "sampling" parts to customers (but that was way back in the early to mid '90s when I was buying parts for a company---that may have long-since changed)...

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

I just finished finalising my 386SX system, and began work on a PCI 486:

386SX:

-AMI 386SX-XT w/32kb L2 cache
-Cyrix 486SRx2 25/50MHz w/1kb L1 cache
-16mb 60ns DRAM
-ATi Mach32 2mb VRAM
-DTK PTI-227B Multi I/O (winbond)
-SoundBlaster16 MultiCD
-SunMoonStar Secondary IDE (internal & external interface)
-Maxtor 4.3GB 4500RPM EIDE HDD
-Matsushita 32X ATAPI CD-ROM (internal)
-Matsushita 1.44meg FDD
-Enlight Desktop Chassis

This system has circa 1990 386SX motherboard clocked at 20MHz. I clipped off the 40MHz oscillator and installed a socket with a 50Mhz oscillator. L2 SRAM cache is rare on 386SX motherboards since they were almost the same price as DX motherbards. Despite having only 32kb SRAM all 16mb of DRAM is being cached.

PCI 486:

-ASUS PVI486SP3 w/256kb L2 cache
-Cyrix 5x86-100GP w/16kb L1 cache
-128mb 60ns FPM DRAM
-Integral ET6100/VPR6100 4mb MDRAM
-Adaptec AHA-2940U2W SCSI
-3com 3c905TX
-Pioneer 16X DVD-ROM
-3x Pioneer 4x CD-ROM
-Full tower AT Chassis

I haven't finished this one yet. I don't have a decent HDD for it. The floppy drive is broken. I need a decent ISA soundcard. 512kb SRAM would be nice. I'd also like to run my UMC PCI 486 board and 5x86 at 133Mhz but they haven't yet arrived in the mail. As it stands everything is properly configured and working but not in a usable condition.

Joined: 22 Apr 2007 Posts: 264 Location: Ohio/USA

My DS1287 replacement arrived today so I got my IBM PS/2 65SX running, just need one working floppy and my PS/2 80 #2 will be running.

I sent my friend in Canada my old 386/SX33 motherboard a week ago didn't look to see if it had cache or not.

Anonymouse Coward do you have pictures of all your systems?
Also did you say 3x 4xcdroms and 1x DVD rom on that 486 PCI Tower? any reason for all those optical drives?

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

386SX systems are kind of neat since they require a little more effort to upgrade. I was really hoping to put my TI486SXL/2 chip onto this board, but as it turns out the socket pads do not match my removable 386SX sockets. So I ended up using the Cyrix clip-on chip instead. Performance with this chip is good enough I guess. I considered slicing off the 386SX with a utility knife and soldering the TI chip in its place, but my skills aren't perfect yet. (i've been practising with surface mount chips on a spare board). I also have an Alaris IBM 486SLC2-66 motherboard I could use for my 386SX system, but it's not as fun since it was made in something like 1995.

I haven't bothered to take photos of all my systems since they are not all complete setups. I am limited for space so with the exception of my real IBM and Commodore stuff I just share a single VGA display among the clones. I pull the system unit off my utility shelf as I need it. I'll probably put a few more pictures up on picasa before I head back to China...unfortunately I left my good camera behind.

So I figured eventually somebody would ask about why I have so many optical drives in the 486 tower. About ten years ago I built a file server that used six identical pioneer 4x SCSI drives. When I was removing the pentium guts from the case I just left some of the drives in there to make up for the fact that I don't have the correct panel covers for the empty bays. I figure it should be convenient for all those damn CD-ROM games that span multiple discs.

Joined: 02 Oct 2004 Posts: 594 Location: Western NC

Quote:

but my skills aren't perfect yet. (i've been practising with surface mount chips on a spare board)

Make sure you get in lots of practice and use the correct equipment (if available). Otherwise you could do something as ludicrous as this:

http://www.youtube.com/watch?v=e5qYG95bbz8

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

Wow, that's way too much solder. I'm surprised he was able to get everything in order by the end, though there was still way to much solder covering the legs of the pins. I really wonder where he learnt the huge "glob technique".

I think clipping the old chip off is probably harder than soldering the new one. It can be done with a regular utility knife, but you have to be REALLY careful not to tear up any of the traces. I'm thinking of experimenting with a dremel instead since it wouldn't require as much force.

I've done a little bit of SMT soldering, but I'm by no means good at it. But, I've seen people do a good job with a regular 30W SMT soldering iron. Usually there's enough solder on the pads so that you don't need to use additional solder for each pin. It really doesn't take much to get SMT chips to stick.

Joined: 02 Oct 2004 Posts: 594 Location: Western NC

Having been in SMT for almost 15 years now, I think I can give some pointers:

1. If using THT (through-hole) soldering equipment, try to find something with a hoof tip (aka: http://www.okinternational.com/product_soldering/mx500microfine )

2. Use as little heat as needed to get the job done (looks like you already knew that).

3. If soldering to a SMT pad on a board, tin the leads first so you won't need as much (or even any) additional solder (you knew that already as well).

4. Tack down any IC's on the corners before finishing the rest of the legs (the only thing the YouTube video got right).

I realize that it's probably impossible to get really good equipment in China, but there might be somewhere it could be borrowed or obtained cheaply....

Joined: 22 Apr 2007 Posts: 264 Location: Ohio/USA

Why would it be impossible to get relay good soldering equipment in China?

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

Oh it's definetly possible to get any kind of equipment you need, some of it is even of pretty decent quality. The problem is that it works on 240V which isn't of much use if you want to use it in north america.

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

Today I located some 45ns DIP DRAMs online. I was really surprised they made them that fast. I'm going to go ahead and slice off the 70ns DRAMs on my ARK1000 based VLB card put some sockets in place. The theory is that installing the faster RAMs will allow this card to operate at faster bus speeds. Currently I can't get it past 33MHz.

What's really weird is that I found this photo on google images of a "Hercules Stingray 64" vlb card, and it is EXACTLY the same as my "2theMax" board....the same FCC number and everything. The only difference was the Hercules board didn't have the SOJ sockets soldered in place, and the DIP ram looked to be higher quality.