About
The one type in listing from the fourth issue of Alternative Micro News, the UK Einstein User Group's magazine, 1990 to 1991, on a bootable Xtal BASIC disc.
Security and the Keyboard Matrix, by Colin Mills, reads the Einstein's key matrix directly through the sound chip's ports with eighteen bytes of machine code, and waits until F0 and F are pressed together: a way of making a program carry on only for someone who knows the key combination.
The listing was printed on pages 14 to 16 of the magazine. The issue can be read on Einstein Reborn; our own scan will return to this library once the private addresses printed in it have been removed. This disc saves you typing the program in.
Running It
Boot the disc, type XBAS, then LOAD "KEYMATRX" and RUN, then hold F0 and F together.
What Is in the Download
A zip holding the disc image as a DSK, the same disc as an MFI for MAME to write to, the listing as BASIC text and as tokenised Xtal BASIC, a README, and the MAME scripts and screen records used to test it, including a sweep of all eight input patterns with F0, F and both held.
Verified
Transcribed from the scan and run on the Einstein in MAME 0.289 with Xtal BASIC 4.2. It printed 0 until F0 was held, then 4, then 4 and 8 together with the message when F was held as well, which are the codes the article gives. The probe of all eight patterns matched the article's reading of the matrix. Not run on real hardware.
Kept as Printed, and One Line Added
As printed, plus a line 180 that prints F0+F RECOGNISED at the point where the article's line 170 says to continue with the rest of your program, so you can see it working.
The program is its author's, published in Alternative Micro News in 1990.
Gallery