post your nudies!

[evildragon]

Haha, another forum I know, an audio forum, has a thread like this, you post your systems insides, hence nudies.

in this case, show off the insides of your vintage computers. i've always been fascinated by the circuits and wiring.

here's my model 25, with all cards removed (SB16 and VGA card), and internal CRT wired up to onboard graphics..

http://img.photobucket.com/albums/v395/Evilweredragon/m25/6.jpg

My model 25 VGA hack:
http://img.photobucket.com/albums/v395/Evilweredragon/vgamod1.jpg
http://img.photobucket.com/albums/v395/Evilweredragon/vgamod2.jpg
http://img.photobucket.com/albums/v395/Evilweredragon/vgamod3.jpg

[vwestlife]

That's the first XT-class machine I've seen using SIMMs. Actually, 256K in DRAM chips on the motherboard, plus two 256K SIMMs, for a total of 768K... of which only 640K is actually used.

Is the video quality good without any shielding on those wires? The analog signals of VGA are more prone to interference than digital video (CGA/EGA), thus most VGA cables are fully shielded and use an RF choke (that's the cylindrical "blob" on the cable).

[evildragon]

I added that ferrite block myself.

The video quality is great, nice and crisp. 16 shades of grey in 640x480 now, instead of the 2 shades before (black and white). Also gained some new resolutions, 360x480 256 shades of grey, and 640x400 (forget how many shades of grey).

[vwestlife]

I added that ferrite block myself.

The video quality is great, nice and crisp. 16 shades of grey in 640x480 now, instead of the 2 shades before (black and white). Also gained some new resolutions, 360x480 256 shades of grey, and 640x400 (forget how many shades of grey).
Actually, VGA monochrome is limited to 64 shades of gray.

[Anonymous Coward]

Is the 64 shade limitation caused by the inability of a black and white display of not being able to produce visual differences between the R, B and G signals?

[andyt31]

This is very modern for this forum, but still cool looking...

1U Rack module with 4 * Embedded PCs (http://andys.dyn-o-saur.com/gallery2/main.php?g2_itemId=424&g2_imageViewsIndex=1)

Ive taken one board out to make a simple web server. Another board will be used to make a PC purely for emulation (C64, CPC etc and maybe MAME too). May even house the board in a old computer... :p

[evildragon]

I combined the RGB values into a single un-weighted luma signal.

The VGA card is jumpered into thinking it's in COLOR mode. When in 256 colors, it can infact produce 256 shades of greys. I've tested this, especially when I load a palette of 256 levels of grey..

See.. If you don't believe me, write a program, and have me photograph it for more proof. I got a good camera. This was in 360x480 resolution.

64 Shades of Grey
http://img.photobucket.com/albums/v395/Evilweredragon/64.jpg

256 Shades of Grey
http://img.photobucket.com/albums/v395/Evilweredragon/256.jpg

Source images...

64 Shades
http://img.photobucket.com/albums/v395/Evilweredragon/64-1.gif

256 Shades
http://img.photobucket.com/albums/v395/Evilweredragon/256-1.gif

I'm not so sure though that the VGA palette can associate enough shades of grey though. BUT! Since they are unweighted RGB combinations, you can mix some colors up to give another shade of grey. I do this in Windows. For an ultra light shade of grey, I use yellow.

PS: Some photos on it in 360x480. Sure looks like 256 shades to me.

http://img.photobucket.com/albums/v395/Evilweredragon/car.jpg

http://img.photobucket.com/albums/v395/Evilweredragon/bottle.jpg

[vwestlife]

Here's my CompuAdd 810 stripped down (ISA cards, hard drive, and floppy drive cage removed).

General inside view:
http://img.photobucket.com/albums/v93/zzm113/compuadd/HPIM0696.jpg
9.54 MHz NEC V20, empty 8087 socket, Award XT BIOS (with built-in support for 1.2/1.44 MB floppy drives!), empty user BIOS socket (I'm tempted to add an IBM Cassette BASIC ROM), 640 kB of 120 ns RAM onboard, piezo beeper.

Closeup of motherboard:
http://img.photobucket.com/albums/v93/zzm113/compuadd/HPIM0690.jpg
Dallas DS1287 clock chip with dead internal battery, onboard HD floppy controller, and yes, onboard IDE! It's IDE-XT, though, so only a handful of drives will work with it.

Closeup of rear corner of motherboard:
http://img.photobucket.com/albums/v93/zzm113/compuadd/HPIM0693.jpg
The two extra ISA slots on the other side of the riser have limited usability; the power wires, floppy/hard drive cables, and game port cable get in the way, and you have to remove the power supply to install or remove cards in those slots.

Rear of the case:
http://img.photobucket.com/albums/v93/zzm113/compuadd/HPIM0699.jpg
The power supply is a standard "so-called-PS/2-type" (145 Watts). Ports for keyboard, parallel, COM1 and COM2 serial, and MDA/Hercules or CGA video along the bottom, and the "optional" game port a bit higher up (a stock 810 doesn't come with the game port, but the functionality is there on the motherboard; all you need is the port itself with a cable to connect it).

Front of case with floppy drives installed:
http://img.photobucket.com/albums/v93/zzm113/compuadd/HPIM0703.jpg
Originally it only had the 5¼" 360 kB drive. I installed a generic 3½" 1.44 MB drive and it works fine, but doesn't quite look right because CompuAdd used a non-standard half-height 3½" drive. I cut part of the original blank trim piece to fill in the gap. The power switch is on the right side of the front panel, and there's a green hard drive LED behind the translucent 810 logo. The CompuAdd logo is engraved into the case and looks really nice! The half-height 3½" hard drive bay hides underneath the two floppy drive bays.

CompuAdd used the same basic case all the way through their early 486 models. They later made a wider version of it, with two side-by-side 5¼" floppy/CD-ROM drive bays, instead of one 5¼" and one 3½".

[Vlad]

I have a CompuAdd 316s I believe which is the wide version. I never saw a desktop so thin and wide until I came across it. I also have a CompuAdd 433 which is gigantic. Roughly as wide as the above mentioned one except 3x 5.25 bays tall and HEAVY! CompuAdd always used a good, solid chassis. A little rough to heft around but good machines.

[vwestlife]

I have a CompuAdd 316s I believe which is the wide version. I never saw a desktop so thin and wide until I came across it. I also have a CompuAdd 433 which is gigantic. Roughly as wide as the above mentioned one except 3x 5.25 bays tall and HEAVY! CompuAdd always used a good, solid chassis. A little rough to heft around but good machines.
This was their "Full Profile" desktop case. All eight slots can accomodate full-length boards!

http://www.kpsurplus.com/images/26bea2acb386d512efa4a678c378fca33f750642.JPG
http://www.kpsurplus.com/images/dcdda6e6c0b3d88fdb0c2cc7469d99114e8c230d.JPG
http://www.kpsurplus.com/images/847b43116f686a09021a9c42127ae1b6c6b6c5e1.JPG

This was their full AT size 386/486 combo EISA motherboard... sixteen 30-pin SIMM slots, two BIOSes, two Dallas DS1287 clock chips!

http://i23.ebayimg.com/02/i/000/b5/52/1ac7_12.JPG

(None of this is mine; all photos taken from current eBay auction pages.)

[Mike Chambers]

aw, i already had my camera on and my pants down. please do not make misleading thread titles in the future. i like this idea though! nifty, i'm going to take some pics. (of the computers, not me)

that model 25 is very neat, never seen inside one before. from the gold color on the CPU, i am thinking that's an AMD chip? or is that NEC...

[Anonymous Coward]

Two dallas chips?!?! What a pain in the ass that must be. There's nothing I hate more than dallas chips, because after they die they render the board practically useless since it's next to impossible to get a replacement. The DS1287 chips aren't too difficult to find, but most of those EISA boards use far less common dallas chips that have no suitable replacements. There are ways to replace the batteries inside of dallas chips but involves cracking or drilling the damn things opened. I tried it twice, and ended up destroying the chip in the process both times since the legs on them are made out of shitty tin.

That's a damn nice EISA board otherwise. Do you think the smaller socket is really for a 386 or for a Weitek chip? Later I'd really like to built a nice EISA 386 system.

[Mike Chambers]

one of my XT clones. this one is made by BMI. (my other XT clone is a motherboard made by "PC's Unlimited" who changed their name a few years later to... DELL. i believe it is the first board "dell" ever made.) it's probably my favorite toy as far as old computers go.

all the cards other than the MFM disk controller right now.

http://rubbermallet.org/xtclone1.jpg

http://rubbermallet.org/xtclone2.jpg
^ pulled out the HDD controller here, so you can get a peek at what was behind it.

http://rubbermallet.org/xtclone3.jpg

and yes, that IS a sony CD-RW drive lol. i was screwing around recently, connecting it to a tertiary IDE connector on an old ISA board... wanted to see if i could get MSCDEX to recognize it... i didn't really have much luck, and i gave up soon. i have just been too lazy to pull it back out.

if i somehow get the 8088 to burn a CD, i WILL BE YOUR NEW GOD but the possibility seems bleak.

[Anonymous Coward]

Hmm...it just may be possible to burn a CD on an XT. I know that there is burning software written for DOS, but I have no idea what kind of CPU it was compiled for.

I would say that if you wanted to do it, SCSI would be the way to go. I have my doubts that you'll be able to find an IDE controller for an XT that supports ATAPI drives. Assuming there is burn software that will run on an 8088 I think it should work as long as you keep the burn speed down. I think anything more than 2X would be risky. 8MHz XT bus can do 500-600kb/sec, but I am not sure if those rates are sustainable.

[vwestlife]

Two dallas chips?!?! What a pain in the ass that must be. There's nothing I hate more than dallas chips, because after they die they render the board practically useless since it's next to impossible to get a replacement. The DS1287 chips aren't too difficult to find, but most of those EISA boards use far less common dallas chips that have no suitable replacements. There are ways to replace the batteries inside of dallas chips but involves cracking or drilling the damn things opened. I tried it twice, and ended up destroying the chip in the process both times since the legs on them are made out of shitty tin.
I couldn't resist. :D

http://i31.tinypic.com/2ljqerc.jpg

[Anonymous Coward]

My worst nightmare.

[Vlad]

What has been seen, cannot be unseen. o_o

[vwestlife]

My worst nightmare.
A Dallas chip's life and soul...
http://media.maxim-ic.com/images/appnotes/503/timekeeping.jpg
http://focus.aps.org/files/focus/v9/st32/pic-v9-st32-1.jpg
http://www.authenticsociety.com/article/img/ThePersistenceOfMemory.SalvadorDali(1931).jpg

[Mike Chambers]

i wish i something more interesting to show you guys than an old run of the mill dime a dozen XT clone... i could snap shots of a huge 286 motherboard, but thats even less interesting.

maybe i should go back to the no pants and camera thing again... at least that would be interesting.

[Vlad]

I'll try to take some pictures of interesting items tomorrow, too late/early now.

[Mike Chambers]

I'll try to take some pictures of interesting items tomorrow, too late/early now.

i know this is off-topic, but the linux community should toss out tux and adopt the LOL WUT pear as the kernel's new mascot. am i alone on this one?

[Vlad]

I was all pumped and ready to take pics but it was raining sideways and clouds were going in circles so it was a good hang out in the basement day. O__O

Yeah, Tux has been around a while, but the Wut pear would be more awesome. Its actually from a surreal painting I'll link to in Humor later. I promise lots of pics soon, an entire album on Picasa.

[Druid6900]

Here's some shots of a Zenith ZDS-158-42 that I have showing it from multiple angles;

http://www.vintagecomputersnparts.com/catalog/popup_image.php?pID=417&invis=1
http://www.vintagecomputersnparts.com/catalog/popup_image.php?pID=417&invis=2
http://www.vintagecomputersnparts.com/catalog/popup_image.php?pID=417&invis=3
http://www.vintagecomputersnparts.com/catalog/popup_image.php?pID=417&invis=4

[vwestlife]

Those Zenith backplane PCs were certainly built like tanks... plus it's a nice touch to have diagnostics and a monitor utility built into ROM.

[mikey99]

Here are a couple of shots of my Sanyo MBC-885 XT Clone I posted in
another thread and thought might be of interest here

http://www.vintage-computer.com/vcforum/attachment.php?attachmentid=665&d=1212298875


http://www.vintage-computer.com/vcforum/attachment.php?attachmentid=664&d=1212298690

[Anonymous Coward]

Did you swipe that 3.5" bay adapter from the Sanyo to put into the AT? They're both the same shade of brown.

[lynchaj]

Hi All,
Here are a couple of projects on my bench without cases

First is the IBM XT motherboard I am repairing. It has no case at all!

Second is the SBC which doesn't have a case either.

So, I guess I have a bunch of nude computers sitting in my basement. :-)

That sounds sick, doesn't it?

Thanks and have a nice day!

Andrew Lynch

[mikey99]

NO , that 3.5 in the AT turned brown after about 6 years of sitting in my
attic, while the IBM plastics kept their original color :-) Back before
I started collecting, now I know better than to put any of my comps
in the attic ! The AT had a 386 mb (with a leaky battery) while in the
attic, but I still had all the original parts, MB etc, also in a box in the attic.
So I ripped the 386 out and put all the original stuff back in there, booted
right up.

BTW I think thats the original color of the Sanyo.

Did you swipe that 3.5" bay adapter from the Sanyo to put into the AT? They're both the same shade of brown.

[evildragon]

aw, i already had my camera on and my pants down. please do not make misleading thread titles in the future. i like this idea though! nifty, i'm going to take some pics. (of the computers, not me)

that model 25 is very neat, never seen inside one before. from the gold color on the CPU, i am thinking that's an AMD chip? or is that NEC...
the gold chip is the Intel 8087 co-proc, and the black chip next to it is an NEC V30..

[vwestlife]

This one isn't mine, but it is an IBM XT-286... the first ever computer with a "baby AT" motherboard, and IBM's first computer to use SIMMs. The pre-VLSI circuitry is probably the most tightly-packed I've seen on a motherboard! :eek:

http://www.yesterpc.com/Hardware/IBM%205162/slideshow/IMG_0787.JPG

And you know that rectangular blank filler plate above the keyboard port on the back of the original XT's case that has no explicable purpose? On the XT-286, that's where the CMOS/clock battery holder goes, so you can change the battery without opening the whole case. Since the XT had that filler plate all the way back to 1983, perhaps it indicates that IBM originally intended for the XT to come with an onboard real-time clock chip.

[curtis]

Okay, I've been following this string for a while and finally got around to working on a prototype IBM Portable PC I picked up a while back and thought I'd show y'all what I got.

http://www.suddenlink.net/pages/curtismc/ppc-proto-top.jpg
http://www.suddenlink.net/pages/curtismc/ppc-proto-back.jpg
http://www.suddenlink.net/pages/curtismc/ppc-proto-mobo.jpg
http://www.suddenlink.net/pages/curtismc/ppc-proto-front.jpg

If you're familiar with the model, you'll quickly notice the storage cubby in the back for the power cord. The motherboard is a standard 64-256K 8 slot mobo, but the outer 3 slots are blocked by the cubby. DUMB!

There is also a subtle difference on the front where the front bezel is slightly recessed instead of flush.

The shielding is also different.

Eventually, I'll get a web page up detailing the differences. Sigh, 36 hours a day just isn't enough anymore.

[vwestlife]

That power cord storage box is strange. Even without it, people still complained that five of its slots could only hold short cards, and two of the long slots were occupied by the floppy and CGA boards. Also, IIRC you could just tuck a power cord into the gap between the rear of the slots and the plastic "trap door" (which ultimately got lost or thrown away on most Portables, I'm sure, just like the clear plastic retaining clip holding the floppy and CGA boards in place).

Do you have the official carrying bag for it? From what I remember, it's dark blue fabric with an IBM logo tag sewn into the stitching, and large finger loops for the zippers.

I gave away my Portable PC a decade ago, and at times I still miss it, even though the snowy amber mono-CGA monitor was pretty awful to look at. Now I have a late '80s generic luggable case with a 9-inch dual-scan paper white CRT (it can display either MDA/Hercules or CGA -- it's the only CGA-compatible monochrome monitor I've seen which uses the RGB input, not composite!) and space for a full-size AT motherboard inside. :eek: The mobo is sideways, with the slots facing out the side, and the "long end" of a full AT mobo tucked under the drive bays. Even more oddly, the owner's manual is in English and it came with a U.S.-type 110V power cord, but the keyboard has a German layout, with the Umlauted vowels and everything!

I'd take pictures of it, but right now it's holding up one end of a makeshift table. Yes, really. :) And it doesn't have any components in it right now, anyway.

[curtis]

Yeah, that's probably why the box got tossed in favor of at least some usable slots.

I THINK I have a tote bag here somewhere. Know I used to, but haven't seen it in a while.

BTW, if you'll look closely at the "GOD" shot (above the computer) you'll notice the clear retainer is right where it should be!

Also the floppy caddy that'll hold a whopping 2-3 diskettes is vented and a different shape.

Weird little differences really makes this one interesting.