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Post by Tom Maneiro on Oct 11, 2005 9:16:42 GMT -5
My 386 box has a new soul... after almost ending in a trashcan! like every 386 in this world... What i got on July 2005? A stock AcerMate 333s (model:ms33d2): -AMD Am386SX-33 (386SX@33MHz) with no FPU/math coprocessor -4Mb of RAM (2MB onboard, 2 30-pin SIMMs of 1Mb each one) -85MB Conner Peripherals HD with Win31, Word 2.0, Excel 4.0 and some other misc apps. -Oak OTI-077 videochip with 256K of VRAM (max: 800x600x16 colors) -3½" and 5¼" floppy drives (the big one with a damaged lock lever) -NO FANCOOLERS! ...and what i have now after more than FOUR YEARS of careful tunning and research: -Same processor, now with a IIT 3C87SX-33 FPU! -Overclocked to 40MHz, with a 80MHz oscillator. Requires more stable RAM. - IBM Deskstar DALA-3540 HD (540MB, jumpered to 1024 sector limit). Talking about perfect fit... -Windows 95 OSR2 (somehow slow!) and Office 4.2 97 Professional! - VB3, PowerCOBOL 3.0L10 (32-bit!), CircuitMaker 6.0 Student Not yet reinstalled -The Ultimate Doom and NO$GMB (gameboy emulator, the only emu that runs fine on a 386 box) - Samsung SC-152L 52X CD drive, sane. AOpen CRW4850 (OEM) 48x12x50x CD burner. Useless... for now? -1MB of VRAM (now: 1024x768x256 colors!) -Two extra 1MB SIMMs, for a big total of 6Mb of RAM - New 5¼" Mitsumi floppy drive (i fuxored the lever of the old one while attempting to fix it, but i found a new drive, a bit faster). These are very reliable, but require a LOT of cleaning. UPDATE: changed Mitsumi 3½" drive with a "dead but alive" Panasonic (i love defective but repairable drives!). UPDATE 2: Changed Mitsumi 5¼" drive by an Epson SD-600 -A fancooler for the 386 (from a dead 486), that lil' square can run very HOT! Removed due to the SCSI card -Case fan (like P4's) - Genius NetMouse (serial) Generic "Sonic" optical PS/2 mouse, with MS IntelliPoint drivers for enabling the wheel to... scroll. -AT&T/Archtek 19.2K voice-fax-modem (model 1914BAV, also works as a basic sound card for Win95) - Crystal 4237B-XQ3-based soundcard: SB-compatible, has an IDE port, supports 3D sound and SRS(r)... and it's good for DOOM! Replaced with a REAL SoundBlaster AWE64 PnP. -Realtek RTL8019A 10Mbit NIC (NE2000-compatible), plus Winsock2 updates: Internet-capable, powered by... IE3.0??? -Adaptec AHA-1542B SCSI-2 host adapter and a HP-branded Quantum Fireball TM 2.1gig SCSI HD with 2 megs of bad sectors, and some other issues. Dead HD... ports available! -Hi-Power 225W AT PSU (just blowed the original, 125W PSU ) -A major cleanup to the system (i washed the case with a hose... nobody does that, but that thing had lots of dust) -A nice wallpaper of a random coachbus anime series, downsampled to 256 colors with ACDSee 2.43 ("your JPEG in 30 seconds") -Misc software ripped from the finest shareware CDs from 1995 -TightVNC, for laggy remote control. Still pending: -16MB of RAM on 4MB 30-pin SIMMs. Seems to be Mission: IMPOSSIBLE - SCSI HD (or a HW solution to plug IDE drives larger than 504MB) Waiting for purchase a proper adapter for 68-to-50 pin SCSI drives - Linux(tm)!-REAL video card, something like an ATi Mach32/64... -100Mbit networking? Any suggestion to expand it more?
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Post by GiGaBiTe on Oct 14, 2005 1:34:25 GMT -5
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Post by Tom Maneiro on Oct 14, 2005 19:04:48 GMT -5
They do not ship to Venezuela... and it's VERY expensive for me. Don't worry, a lab in my university is FULL of dead 386, 486 and Pentium boards. It should not be hard to find a working 387SX-33... In other news, i have a 286, a 486DX2-25, a 486DX4-100 (with broken pins), and a very early Pentium. Also i got a lot of dead 286 and 486 boards from a trashcan in the university (nice way to waste state assets, eh?). From the 286 board i ripped the Video RAM (44256 chips, in the same DIP format of my board). Also have a extra 5¼ floppy drive, a dead 52X CD drive, lots of dead Trident videocards... man,, i'm a magnet for old and fuxored hardware! Now what i do with these stuff? I'm thinking in decorate my room with the boards, but i need a very strong adhesive tape...
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oompa loompa
I AM THE GOVERNATOR
"Git 'Er Dun!"
Posts: 1,301
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Post by oompa loompa on Oct 17, 2005 16:09:26 GMT -5
i usually desolder all the parts i can use off old motherboards, and then just toss everything away, since the boards are practically useless, unless you want to build another system
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Post by Tom Maneiro on Oct 18, 2005 8:47:58 GMT -5
How you desolder a i386SX, a TVGA900 or even a lil' RAM chip without fuxoring it?
Anyway, now these boards are in a window.....
I went to the Digital Circuits lab on the university, they have LOTS of old computer pieces (even found a 386DX-40!), but... there are NO 80387SX's! And, neither I live in the US nor have 20 bucks to buy the coprocessor in eBay... Too bad.
The good news is that they have a bunch of 30-pin SIMMs, but i must carry with my box (really it is not mine, but their next possible owner was a trashcan before my rescue) to the university to test EACH DAMN SIMM MODULE! (none of these have their capacity printed). The CPU box is heavy, but at least i have my last choice here to expand my RAM.
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Post by GiGaBiTe on Oct 23, 2005 1:16:22 GMT -5
desoldering surface mounted chips isnt easy, but its not impossible either. although it takes alot fo skill to do it, and a few tools.
1) a soldering pin (a soldering gun gets WAY too hot)
2) a solder braid (preferred for surface mount) or a solder sucker gun
just heat up the connections one at a time and remove the solder with the solder braid, or the solder gun. just make sure you dont apply the solder pins heat to the chip for long periods of time, else you will fry it.
to get the chip back on there, that is relatively easy, just line up the pins, and start applying solder to the pins on the surface. if the surfaces are clean, then it should stick. just make sure that the solder doesnt bridge across to another pin, else it will probably fry the board.
also if your going to increase the cpu speed from like 33 MHz to 40 MHz, you need to replace the CLK crystal (its usually the same MHz rating as the CPU or 2x the speed of the cpu.
now dont ask me where to get a faster clock crystal, as i have no idea. but they look like small silver bricks with 4 leads in each corner on the bottom of the brick. it also has the MHz rating printed on the top of the crystal (most of the time)
reading ram chips (up to the 72 pin era) is easy once you understand it.
if you look at any chip on the memory, it will generally have a number like..
HC256Ac5000
you can tell right off that its probably a 256 Kbyte stick. (each chip isnt 256 Kbytes)
now since 30 pin simms are 8 bits wide, the early sims will have 8 chips on them (each chip is one bit) if you see a stick with 9 chips on it, the extra bit is for parity. if not, its non-parity ram.
later sticks put 2 and 4 bits of ram on one IC, so you would have sticks with 4 or 5 chips, or 2 or 3 chips (non-parity and parity)
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Post by Tom Maneiro on Oct 25, 2005 10:13:09 GMT -5
I got a spare 30-pin SIMM from the trash... but your method did not worked at beginning. The chips are two OKI M5117400-70J and one VP4100GB-7. Google falied to get more info (most of the results were to part resellers, but nothing more). After a while, i found this:
M511740070J Refurbished PULLS 4MX4 PAGE MODE DRAM OKISEMICONDUCTORGROUP
So... i have a 4MB SIMM?? These are rare, but i only have one... and those babies works in pairs!
And what the heck does the other chip there? The parity stuff?
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Post by GiGaBiTe on Oct 30, 2005 0:26:45 GMT -5
511740070
5117400 is an all too familiar number to me. it doesnt mean 4 megs, its a 16 meg simm (pretty sure) and the 70 number behind it means its a 70 ns timing.
1, 2 and 4 meg sticks are not rare at all. you can find a ton of them in the old macintosh II series. 16 and 32 meg 30 pin simms are very rare, and still expensive.
its most likely it is a 16 meg stick, because if it only has 3 chips on it, its a newer version of the 30 pin simm.
as for that 3rd chip, it means the stick has parity check. so if the stick has some bad memory addresses, you will get the error message "parity error, system halted" upon startup.
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Post by Tom Maneiro on Oct 30, 2005 14:12:58 GMT -5
WTF? Do you mean that there are 30-pin SIMMs larger than 4MB? And i got a RARE stick of 16M? Cool...
Unfortunately, my computer seems to not support more than 4MB per stick. What could happen if i install a couple of 16M SIMMs? I've heard that due to the 16-bit bus, 386SX's does not support large amounts of RAM...
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Post by GiGaBiTe on Oct 31, 2005 14:44:53 GMT -5
the 386 cpu can address up to 4 GB of ram. there is no limit on that end. the problem is your motherboard. who would ever need that much ram back then? dos couldnt address more than 64 megs efficently so motherboard manufacturers pretty much capped them with 4 meg per stick in the memory controler.
so thats basically what happened on all of those old boards. there are probably some newer 386 boards that support the bigger size ram sticks, but those are rare. and you probably wont find the good boards in computers built by manufacturers.
the 486 era boards pretty much right off could support 16 meg sticks standard, and before they went to 72 pin simms they got 32 in there somewhere.
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oompa loompa
I AM THE GOVERNATOR
"Git 'Er Dun!"
Posts: 1,301
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Post by oompa loompa on Nov 3, 2005 17:18:57 GMT -5
16 meg and 32 meg simms (30-pin) was very very hard to obtain in the days when the 486 came out, and is still probably hard to get today. i think the largest amount of memory a -normal- 386 could be upgraded to is 16 megs, since 16 megs was already over kill for a 386 (but for a 486, was a pretty nice system =D). i plan to rewrite the bios for this small 386 pc motherboard for fun, later, so that i could use "devster dos" =P
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Post by Tom Maneiro on Nov 5, 2005 7:50:43 GMT -5
BIOS update, eh? Maybe you could rewrite this Acer BIOS to support more than 512 meg HDs and larger RAM sizes, all with a nicer setup proggy The BIOS are in the Acer MX FTP (1.2r1.9 from 1993!)..
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Post by GiGaBiTe on Nov 5, 2005 23:54:34 GMT -5
most likely not possible.
definitely not possible.
depends on how big the eeprom (if its an eeprom) is.
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Post by Tom Maneiro on Nov 6, 2005 15:26:53 GMT -5
damn, i forgot the "SX" thing.... But for HDs, at least something can be done there. The BIOS dump is 64KB, so it may be difficult to fit a new setup program there (i've checked and there are no long FFs fields there)
A couple of strings from the BIOS:
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Post by GiGaBiTe on Nov 8, 2005 23:33:04 GMT -5
ROFL! a 64 kb bios, yea you are definitely not going to fit anything fancy in that. if it was a 512kb or 1 mb rom, then you might have had something. but 64 kb, sheesh.
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