386 Upgrades

Cyrix CPU Info Tim O'Connor's page
ETPARTS.txt Evergreen Upgrades

Evergreen Technologies
   IBM486SLC2 25/50
   486 Now
   Lightning 486
Improve it Technologies Make it 486 TI486SLC50
Evergreen Cyrix Interposer (with Cx486DLC25GP)
Cx486SRX2 25/50M P Snap-on
Kingston Upgrade
IBM486SLC & Blue Lightning

Content created by Sandy. Edited by Major Tom.

Cache enabling utilities are mandatory to use with these clock-multiplying CPUs.

* "UGT" label observed in pictures means "Upgrade Technology Co. Ltd". It was a well known developer of upgrading parts mainly for PS/55. The company imported upgrade products made by Evergreen and Kingston and they made some modification for those products.

Evergreen Technologies

Evergreen made various kind of processor upgrading parts for 286 to 486 class systems. IBM486SLC and BL processors were mainly used for their upgrading products. For detailed parts list, please check Evergreen's ETPARTS.txt.

REVto486 Utility (requires a 720KB floppy)

386SX3+ (Evergreen Parts #300, #279) [Editor's Recommendation]

IBM486 3x capable processors were used for these models. #300 was for 20/60 or 25/75 upgrade and #279 was for 16/48 upgrade. In old Japanese catalog, parts #298 was listed for 16/24 to 25/75 systems. ETPARTS says the chips used for these models are "Blue Lightning 25/75" (or 20/60).

I'm wondering if CPUs used for these Evergreen upgrades were really a "IBM486SLC3" processor or not. Outlines for IBM 486SLC3 Processor upgrade in Louis' page seems that a CPU used for the upgrade card is same size with intel 386SX (U4/SLC3 is smaller than U2/387SX). And also it is almost same with a CPU outlined in IBM486SLC2 Upgrade page. While the chip used in Evergreens 3x speed upgrade in my hand is bigger than those used in above mentioned upgrade by IBM. The chip is just same size with IBM486BL3 used for their Processor Upgrade for 386DX systems. It seems to me that a real 32-bit Blue Lightning (BL3) was used for 386SX upgrading. IBM486SLC2 is always refereed as "SLC2" but not as "Blue Lightning (at least in old PC magazines in Japan). Would like to see an exact "IBM486SLC3" used on "IBM 486SLC3 Processor Upgrade Kit or in model 57SLC3.

The model in pictures below is rated 20/60MHz but it is capable to run in 75 MHz. Don't know exact part number because I got it free as "Junk" without packaging box. Most possibly it is #300. It run fine on 5530-U (intel 386SX system). Then I tried to load it on 8557 Ultimedia and, in order to put it on IBM386SLC2 on the planar, I grooved one corner of CPU holder. Unfortunately 8557 didn't work with the upgrade. I didn't check further to clarify the reason why it didn't boot.

Easy to use. Just snap it on atop of existing 386SX CPU.

IBM486SLC2 25/50 (Evergreen Parts number unknown)

Same as above. IBM486SLC2 is apparently different from BL2 or 3 above. SLC2 is smaller than BL and is just same size with Intel 386SX.

IBM486SCL25/25 was not available as a CPU "unit". Some of PC upgrade shop soldered off IBM486SLC2s from PCB and then used those chips for their Laptop upgrade program. One in my hand is a such PCB. You can see there are two set of solder pads, for bigger CPU and smaller CPU. It's difficult to confirm through photo but actually the inner solder pads were used (CPU was once there).

TI486SLC2 (Evergreen Part #289, my package says #288)

Tested it in my 5530-Uxx with intel 386SX, but it didn't work. Don't know if this unit was defective or the kit itself is incompatible with 5530-U (i386SX). 5530-U didn't boot at all.

Note: This upgrade CPU is not compatible for systems which has a 386SX in step A and step B. Test your system using SXCHK.EXE if it yours is compatible with this upgrade. SXCHK.EXE is contained in REV to 486 cache utility diskette.

TI486SLC2 has 8KB L1 cache and it should be faster than Cyrix 486SLC with 1KB L1 cache.

386DX2+ (Evergreen Parts #271 and #272)

TI486SXLC/2 series were used for these models.
TI486SXLC/2 which was refereed as "TI Potomac" is clock-doubling CPU with 8KB L1 cache.

When I pull off the CPU from the associated socket to take pictures, A14 pin was torn off! Oh, my... Can I solder the pin?

386DX3+ [Editor's Recommendation]

IBM Blue Lightning 3x processor (BL3) was used for this model. Depending on system board clock, there were two versions available:

  1. IBM486BL3 20/60 Evergreen Parts #261 (not listed in ETPARTS.txt)
  2. IBM486BL3 25/75 Evergreen Parts #263

If you don't consider overclocking of Kingston Lightning 486 or 486Now, REV to 486 386DX3+ is the fastest upgrade part to boost your 8570 or 8580. There is a socket for co-processor but I have not ever seen co-pro for BL2/BL3 which fit to the socket on the PCB. Even without co-pro, Evergreen's BL3 upgrades are really powerful. A weak point of Evergreen's upgrades using BL3 for 386 PGA socket is it's pin connection between PCB and PGA socket.

Note: The socket plug is surface-mount. Frequent removal/installation may break the pin soldering - like pictured HERE.

   Question: What is an IBM 486BL2 or 486BL3 (Blue Lightning) processor?
   Answer: It is an IBM-developed derivative of the Intel 486SX chip that comes in two "flavors": the clock-doubling 486BL2 and clock-tripling 486BL3.


Kingston's approach for 386 upgrading was a bit different from Evergreen. Their products have own clock generator on the cards. Both 486 Now and Lightning 486 use own CPU external clock isolated from system clock of the planar. Kingston still offers drivers and manuals at their web site.

486 Now

See HERE for outline and detailed information.

Mine is from "garbage box" and without connection pins for PGA socket. I have both 20 MHz and 33 MHz versions but both of them have not pin extender. Would like to check if it can take 5x86ers.

486NOW.EXE PS/2 486/Now! disk w/drivers. (240KB)
COP487.SYS Divide by zero error fix for 486/NOW! (1KB)

Lightning 486

Kingston's Lightning 486 may be considered as a counter product against Evergreens "REV to 486". This unit has OSC on the card and CPU base clock is supplied from it's own clock generator but not from planar. Card has 66 MHz OSC and an IBM 486BL2-66 on the card run in 66 MHz clock-doubled speed in any systems regardless to main planar base clock such as 16 MHz, 20 MHz and 25 MHz. A surprising information was reported to the MCA Forum that the reporter used his Lightning 486 with 90 MHz OSC installed and his lightning 486 actually run in 90 MHz inner speed.

For detailed information please click here. The page is about the IBM 486DLC2 Upgrade but it's equivalent to the Kingston variant.

486BL66.EXE Lightning/486 (486BL/66) Diskette v1.0. (22KB)
LIGHT486.EXE Lightning/486 Drive v1.2b. (151KB)

Improve it Technologies Make it 486 (TI486SLC50)

When I bought my first 5570-V (8580-Axx analogous) from a individual trader, the seller sold me some of 386 upgrade CPUs very cheap (almost free). "Make it 486" was included in the volume. Unfortunately now I don't have it. I gave it to a friend of mine.
Pictures below is scanned image of it's packaging box. As far as I remember outlook of the kit (CPU) is different from a picture of the package.
In order to activate L1 cache, a special cache utility is required. The driver was supplied in 5.25" floppy so I had to buy an external 5.25" floppy drive to read the driver. I tested it on my 5541-T (386DX-20 system). It was faster than Cyrix upgrades but slower than Evergreen's REV to 486 386DX3+ in clock-doubled 50MHz operation.

Pic #1 Front of the package
Pic #2 Back of the package
Pic #3 Important note (it says a CPU was different version from the pictures in the installation manual.)

Make it 486 utility (DXP format. requires 720KB floppy)

Brief note from "Setup Programs" guide sheet in the diskette envelope:
"The Make-it 486 modules start up with the on-board cache not activate. This is a feature of the processor chip. The cache is required for high-speed operation of your new 486. Activation of the cache is accomplished by running a program each time your computer is powered up. A program to activate the cache (CACHE486.EXE) and a set-up program is on this diskette"

Evergreen Cyrix Interposer

No information for this unit. Maybe Cx486DLC25GP shown below is associated with this kit. This one is not listed in ETPARTS text too. Cache enabler maybe required for this upgrade kit.

Cx486DLC Specs
Package: PGA-132
Clock: 25/33/40 MHz
L1 cache: 1 KB
Input Voltage: 5 V
Pin compatible with i386DX

TX486DLC is an equivalent.

Cx486SRX2 25/50M P Snap-on

Snap on kit upgrading 386SX system. Don't know if it can be used in PS/2 or PS/55. This kit is compatible for i386SX in step C and later (step D and combo step).

Cx486SRX2 Specs
Package: QFP-100
External bus: 16 bit
L1 Cache: 1 KB
Input Voltage: 5 V
Pin compatible with i386SX
Base clock: 16/20/25 MHz. Internal: 32/40/50 MHz

Kingston Upgrade (May be a variation of 386SX Now)

Not so sure if this is for 286 systems or for 386SX systems. If this one is for 386SX, it should be installed to 387SX PLCC socket like IBM 486SLC2 upgrade for 855x. But the CPU is Cx486SLC-25, then it may be for 286systems, I think...
I can't check the card if it is dead or alive, also if it is compatible with PS/2 or not. I don't have 286 system this moment. I just got the card in a grab together with some of above mentioned Upgrades.

Cx486SLC (SLC-25MP) is used for this model. Another model has a Cx486SLC/3-33MP (33MHz) on the PCB.

Most probably, these Cyrix 386 CPUs have 1KB L1 cache.

IBM 486SLC2/SLC3 and Blue Lightning

See IBM's official 486 Processors FAQ for additional information.

Product Pkg. Based
& Mult.
386SLC QFP i386SX No 8 KB 16-bit 20-25, 1x 5 V
386SLC2 QFP i386SX No 8 KB 16-bit 40-50, 2x 5 V
486SLC QFP i386SX Yes 16 KB 16-bit 25, 1x 3.6 V
486SLC2 QFP i386SX Yes 16 KB 16-bit 50, 2x 3.6 V
486SLC3 QFP i386SX Yes 16 KB 16-bit 75, 3x 3.6 V
486DLC2 or BL2 QFP i486SX Yes 16 KB 32-bit 66, 2x 3.3 V
486DLC2 PGA i486SX Yes 16 KB 32-bit 66, 2x 5 V
486BL3 QFP i486SX Yes 16 KB 32-bit 75, 3x 3.3 V

None of the above listed CPUs have a built-in Floating Point Unit (FPU, math co-pro). Intel 486SX/DX has 8 KB L1 cache.

Some laptops such as TP700/700C has an IBM486SLC25. If you are lucky your system may run in 50MHz inner speed using utility which enables clock-doubling circuit in the CPU (if yours is actually a 486SLC2-50 even though the system is rated at 25MHz). Few systems rated 25MHz have actually an IBM486SLC2-50. For example, later model of TP550BJ (with built-in Canon bubble-jet printer, sold only inside Japan) was announced that it had an "IBM486SLC" but few of this model actually run at 50MHz when appropriate cache enabler is used.

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