Compaq SLT/256 Portable Computer

Mus.Cat. NEWUC:2014.1 Mnfctr: Compaq Date: 1988 Ser. No: 1848HU3H0083 Model: 2680
Comp: Personal Computer Length: 343mm Width: 226mm Height: 104mm Weight: 7Kg

This is the COMPAQ SLT/256 portable computer closed ready for porting.


Opened up ready for use.


Disassembled, outer case on right, then keyboard, then floppy disk and hard disk drive, 2 memory DIMMs, battery and more memory, and finally the mother board.


We start with the mother board. Just right of centre is a 4x17 68 lead PLCC (Plastic leaded Chip Carrier) it is labelled (upside down) CS80C286-12. This is the 12.5MHz CPU/Microprocessor. Although in 1988 the 386 architecture was available, Compaq chose this 286 architecture because the 386 CPU used too much power making the battery life too short. Using the 286 CPU gave a three hour battery life between charges. It looks like two layers of printed circuit board on the front.


This is the rear of the motherboard, it looks like two layers of printed circuit board as well. There are 162 resistors and 171 capacitors on the rear.


This is "TRIUMPH PIGGY MEMORY BRD". It has twelve TC51832FL-10 chips, each is 32KBytes of memory.




Two 1 MByte DIMMS. (Dual Inline Memory Modules.)


The other side of the DIMMS.


Top of 3.5 inch floppy disk drive.


Underside of floppy drive


Printed circuit board of floppy disk drive. The drive has a three-phase brushless DC motor.


Top of the 40MByte hard disk drive. It was mounted so as to withstand rough treatment of the portable computer.

Doing a search on the web unearths:

Formatted Capacity (MB=1,000,000): 20 MB
Cylinders:                         615
Sectors:                           17
Heads:	                           2
Disks:	                           1
Buffer Size:	                   8KB, segmented
Average Seek:	                   27 ms
Single Track	                   8 ms
Rotation Speed/Avg. Latency	   3574 rpm / 8.4
Transfer Rate to/from media	   1.25 MB/sec
Transfer Rate to/from buffer	   4.0 MB/sec
TPI (Tracks Per Inch)	           1150
BPI (KBits Per Inch)	           21,379
Size 	                           1" Height x 4.0" Wide x 5.75" Depth
Weight	                           1.1 lbs


The electronics of the hard disk drive.


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