EUG PD
1st August 1995
Author: Derek Walker
Publisher: Watford Electronics
Machine: BBC B/B+/Master 128
Published in EUG #21
What is a MegaBuffer? Well, it's simply a printer buffer. "What is a printer buffer?" I hear you ask!
No? Well, I'm going to tell you anyway...
A printer is usually the slowest part of any computer system, because its speed is limited by its mechanics. The computer, however, can produce data to be printed far faster then the printer can take it, so that most of the time, the computer is just waiting for the printer and not doing anything useful. A printer buffer overcomes this problem, by taking data from the computer as fast as it can be sent and storing it in its own memory until the printer can accept it. The computer is therefore freed for other uses very quickly leaving the printer buffer to take care of the printing. It's important to note that a printer buffer will not actually produce a printout more quickly, but will allow you to use the computer while the printer is running.
This particular little gadget measures only 5" x 5" x 1.5" and is bristling with useful features - such as being able to produce several copies of a printout without having to make the computer send the data again. It even has a help mode!
Some of the operating modes available are:
- Sink mode
In this mode, all data sent by the computer is read in and ignored. Useful if you want to stop the printout without escaping from the program. - Straight mode
In this mode the data is send directly to the printer - the buffer action is disabled. The main use of this mode is when you are manually feeding single sheets into a printer, where there is no point in buffering, as the software has to wait for you to change sheets. - Buffer mode
This is the most frequently used mode, it takes the data from the computer at a fast rate and stores it until the printer is ready for it. - Multi-copy mode
Another very useful mode, the buffer takes the data from the computer and passes it to the printer as in the buffer mode but it retains in its memory the full document (memory permitting) so, at the press of button, the document can be reprinted. In some case the second print occurs a lot faster than the first, i.e. in Stop Press, the computer is actually slower than the printer as there is quite a lot of calculation involved to produce each line - second time around it's the buffer and it's printed out in a jiff. - Help mode
Self explanatory - it prints out basic operating instructions for each mode.
There are other modes, but are seldom used such as Filter mode, Hex 1 mode, Hex 2 mode, Hex 3 mode and Self Test mode.
All in all its a useful wee gadget and well worth getting a hold of one if you find you are drinking too much coffee hanging around waiting on your printer to catch up with you.
Derek Walker, EUG #21