Simple Low Cost Quick Medical Prescription System

• There was a need to simplify and quicken the process of prescribing medicines for a not-so computer-aware medical practitioner.
• Many alternatives were considered: low-cost android tablets, laptops, etc.
• A small x86 device like a Thinclient was sufficient to do the job. Luckily found a guy selling thinclients on Olx here in India. Got a HP t5135, this can be mounted behind the monitor.
• A Doctor can enter the name of the patient, age, weight and choose to add drugs, dosages & diagnoses. There was no requirement to store the patient records for follow up.
• All operation of this System is done by means of the Numeric keypad and the Function keys. The Function keys are color coded further to enable easy identification and choice of keys.
• It allows a doctor to add or delete drugs, dosages and diagnosis.
• It interfaces to a dot matrix printer and can print the prescription.
• This allows fast prescription, similar in principle to the vast quick bill printing  device used by the pay & eat hotels here.
• The price is used 100$ with a 17" monitor and a thinclient.
• The UI is also color coded to ease identification with key. 
• Crux 2.7 distrib Crux was customized to boot the Thinclient which has 100MB RAM and boots off USB. Crux is a very fast Linux distribution and easily customisable.
• Extlinux was used to boot the USB stick. It uses a extlinux.conf file. Created thus:
• default /boot/kernl initrd="some initrd" vga=0x317 quiet
• display splash.txt
• The VGA mode is used to enable frame-buffer so that a splash image can be used at boot. The way to create a config file for extlinux
• Octal value ie 030 followed by name of file
• Create by using echo -e "\030imagefile" > splash.txt 
• The image file has to be of the type lss16
• How to create the splash image
• With gimp, create a 640x480 pixel file with indexed colors of upto 256 colors.
• Save this as a ppm file.
• use ppmtolss16 < orig.ppm > orig.lss16 to create the lss16 image file.
• Include this name as the file for extlinux to search for in splash.txt
• Install extlinux to the usb disk by extlinux -i /mount_point_of_usb
• No modules were used to boot the Linux kernel. All functionality was built statically into the kernel.
• Unnecessary services like the network, crond were disabled.
• The machine boots in roughly 15 secs.