Bootable Grid

Author: crocidb
Category: Christmas Challenge
System:   IBM PC
Language: Assembler (NASM)
Len source code: 691 bytes
Len exe file:    512 bytes
Len code only:   622 bytes
Instructions:
 This runs on an IBM PC Bootsector. To run it with an emulator (QEMU):
  `qemu-system-i386 -fda vccc.bin`
 Also possible to flash `vccc.bin` file into a usb-drive (or a Floppy Disk)
 and boot your IBM PC with it.
Description:
 Quite possibly the most naive way, it loops per line and print `*` everytime 
 the modulo of counter (`AX`) hits the assigned value (`BX`). The counter is
 signed and starts at `-3` and goes to `3`. It runs on the bootsector, so no
 operating system required.
Comments:
 There's a small glitch character appearing in the 17th line that I wish I had
 time to debug, but I'll have to go with it.