Windows XP enables First-In-First-Out (FIFO) buffers for each COM port. These buffers tend to interfere with printers using Xon/Xoff flow control, so Aloha POS disables these buffers on all COM ports on all terminals, regardless of the printer type. (In the event of a printer or COM port failure, a printer using Xon/Xoff flow control may be temporally connected to the port in the future.)
To access the FIFO buffer settings, select Start/Settings/Control Panel/System or right click My Computer and select Properties. Select Hardware/Device Manager, and click the plus sign (+) next to Ports to expand it. Select each port one at a time, and select Properties/Port Settings/Advanced. Clear 'Use FIFO buffer'. Repeat for each COM port. The LPT port does not have this option.
Try this.
Cheers,
Coorsman