Need to upgrade the CPU to make it faster.
I’ll be trying a TI486SXLC2-G50-PQ to upgrade from 25MHz to 50MHz by desoldering the Am386 SX / SXL-25 and soldering on the new TI486SXLC2-G50-PQ.
What’s Known
- 100-pin Plastic QFP (Quad Flat Package)
- Likely the Am386 and TI486SXLC2-G50-PQ are both 5V.
I guess there is one way to find out if it works. Since I have a functional 486SLC board and my 386SX board is damaged by NiCad battery leakage I might as well give this a whirl.
In addition to a replacement CPU, it looks like a crystal oscillator is also a good idea.
It would need to be DIP-4 Form Factor (Rectangular).
Update: 21st July 2012
It didn’t work… The board has had components salvaged and is now scrapped.
Pictures and video to come later on.
Update: 8th November 2012
Here’s all the notes I had on the attempted mod. Hope it can be of use for someone out there.
Am386SX/SXL-25 is 5V on Mega PC
Package Type: Plastic PQFP-100
Cyrix Cx486SLC/e
http://www.ukcpu.net/Collection/Processors/TI/x86/386/386.asp
486SXLC2-G50-PQ – 5V
486 Related Cache Enablers
File Name Contents Size Written by
REVto486.EXE Associated utility of REV to 486. For IBM486SLC/BL. Ver.2.0
May work for 386DX2+ ( TI486SLC ) though not yet tested. 226 KB Evergreen
CX486slc.EXE Cache Enabler for Cyrix CX486SLC with 1 KB L1 137 KB Evergreen
MAKE486.EXE Cache Enabler for Make it 486 Upgrade ( TI486SXL2 ) 207 KB Improve it Tech
PQFP 100
Intel NG80386
CQFP 100
Cyrix Cx486SLC/e
PQFP (Plastic Quad Flat Package)
CQFP (Ceramic Quad Flat Package)
In December 1993 Cyrix released a clock doubled version (25/50 MHz) cx486SLC2, as well as a clip-on upgrade for 386SX systems, the cx486SRx2 (16/33, 20/40 & 25/50 MHz).
RESOLDER CPU
IBM 486SLC/2-50
IBM 486SLC/2-66
Cyrix 486SLC-33
Socketed CPU for 386
386SX cannot be socketed – 100 pin PQFP.
Socketed Crystal Oscillator (386) – DIL-14 / DIP-14 – Purchased by Accident…
386SX – DIP-4 Form Factor (Rectangular) – No point in socketing
Might need 50MHz or 100MHz crystals – Is the 50MHz a double pumped 25MHz?
Already a 50MHz Crystal for 25MHz CPU onboard.
