IBM 386SLC

The 386SLC was an Intel-licensed version of the 386SX (32-bit internal, 16-bit external, 24-bit memory addressing), developed and manufactured by IBM in 1991. It included power-management capabilities and an 8KB internal cache, which caused it to run as fast as 386DX processors of the same speed, which were considerably more expensive. Known inside IBM as "Super Little Chip" for its initials, it was used in IBM PS/2 35, 40 56 Series and in IBM PS/ValuePoint, but never gained much market share. This was mainly due to an agreement with Intel, in which IBM was not allowed to sell their CPUs if they were not part of a system or upgrade board. It was also marketed as an optional upgrade for 8086-equipped IBM PS/2 25 Series computers.

Design and Technology

Built with complementary metal oxide semiconductor (CMOS) technology, the IBM 386SLC had a 161-square millimeter die. It was available with clock speeds of 16, 20, and 25 MHz. The 25 MHz model produced only 2.5 watts of dissipated power, making it specially well suited for laptops and other portable devices.

Despite the the fact that the SLC and DLC chips are bus compatible with i386SX and i386DX respectively, they can not be used as drop-in replacements as they are not pin-compatible.

IBM 486SLC

Is an improved version of the IBM 386SLC, based on the Intel core. IBM 486SLC featured 16Kb of L1 cache and the i486 instruction set. It had a 1.349 mln. transistors, 69mm² die. Manufactured in 1992. 100-pin PQFP, 33 MHz FSB. The 486SLC was also available in a clock-doubled version, the 486SLC2 (50,66 MHz), and later in a clock tripled-version, the 486SLC3 (60,75,100 MHz).

IBM 486DLC (Blue Lightning)

The 486DLC is a fully 32-bit version of the 486SLC, with 1.4 mln transistors on the 82mm² die, 0.8µm CMOS. The Package is 132-pin QFP. In July, 1993 IBM produced clock-doubled and clock-tripled versions of the chip, the 486DLC2 (486BLX2) and the 486DLC3 (486BLX3) respectively. The chips were available from 50 to 100 MHz and were sold by IBM only. IBM later marketed 168-pin PGA Blue Lightning 486 CPUs, but these are technically not related to earlier Blue Lightning models as they are based on the Cyrix CPU core.

ee also

* Intel 386
* IBM PS/2
* IBM PS/ValuePoint
* IBM ThinkPad
* IBM 5x86C - based on the Cyrix core

References

* [http://www.pcmag.com/encyclopedia_term/0,2542,t=386SLC&i=37060,00.asp PC Magazine's article]
* [http://www.cpu-world.com/info/IBM-parts.html IBM parts]