More Room for Your Robot Stuff
By Fred Eady
I finally had gone high tech. I had just purchased my very first hard drive. The cost ... $50 for
a full-sized 5 MB drive. Within a few days, I had managed to convince my IBM 5150 PC to
give up one of its full-sized 160 KB 5. 25 inch floppy drive slots for the high-capacity 5 MB
hard drive. My 5150 was highly modified. After throwing away the original 8088 and
replacing it with a newer and faster NEC V20, I cranked up the original 4. 77 MHz CPU clock
frequency to 8 MHz and installed a set of 5160 BIOS ROMs. The 5160 was called the XT at
that time and came standard with a 10 MB hard drive. If you had more money than you
could stand, you could opt to purchase the expansion unit which enabled you to install up
to two more 10 MB drives. Installing a mux IC and activating a jumper allowed me to take
the motherboard memory up to the maximum of 640 KB. Things were good and Microsoft
was king.
The 8088 and NEC V20 could not stand totally alone. Both microprocessors required
external “helper” ICs to operate. I just pushed a 2 GB MicroSD card into its socket which
is under the control of a PIC18F46J50 microcontroller that is standing alone and running at
48 MHz. Things are good and Microsoft is still king. That MicroSD card I just installed stores
files in the Microsoft FAT format.
58 SERVO 10.2010
