When I read Ray Thomas's letter in EUG #6, I was puzzled as to why Howard's unlocker program would not work with the Elk in 64K mode. Now that I have upgraded to 64K myself I have, I think, found the answer. As with all things that puzzle me, I am never satisfied until I know and I hope that I am not treading on Howard's toes in providing it!

The simple answer is to relocate it as he suggests in the REM statement. It can be located at any suitable address, I have tried this out at various addresses including &120 (The unused part of the 6502 stack!) and it seems to be satisfactory there.

When the Elk is in 64K mode, HIMEM is at &8000 and although you can still type HIMEM=HIMEM-&22 or HIMEM=&7F00 to alter it, the Elk doesn't like it! The Basic Stack remains at &8000, the machine code is not fully assembled and the Elk hangs up. However, if you ignore HIMEM by deleting line 80 in the unlocker program and alter lines to:

      100 P%=&7FDE
      200 ?&221=&7F

then the program works. However, if the stack is used then the code will be deleted.

I would suggest it is better to make further changes which would make the program re-locatable. To do this, add:

      80 INPUT"Address to assemble to (default &900) "a$
      85 IFa$="" a$="900"
      87 code%=EVAL("&"+a$)

and alter lines to:

     100 P%=code%
     190 ?&220=code% MOD256
     200 ?&221=code% DIV256

You will find this new version on this disk.

Incidentally, I do not think you can lock a program on tape accidentally as Will says. The way to to this is by using the above program but altering AND#&FE in line 140 to ORA#1.

Paul Woodward asks in EUG #9 for the Elk memory map. It was published in Electron User April 1988 onwards. I have re-typed this information into a series of programs which use the expanded graphics of my printer and should work on any EPSON standard printer. The listing can be printed out on nine sheets of A4 paper or simply displayed on the screen.

I may add that I am possibly one of older members of the group having retired some years ago - I must push up the average age a bit! If there are any members near enough to meet up with me, I should be pleased to have a chat! If not, I am always ready to correspond.

Richard Dimond

My remarks about unlocking programs were meant to imply that the only software that could be unlocked and copied without technically breaking the law would be your own self-penned efforts or other non-copyrighted material. Still, as all Electron owners are as honest as the day is long, there was no need for me to say thing really...was there?

It's probably just my printer (Panasonic KX-P1081), but the only 'graphics' I get from the memory map programs are italic 'D's, 'M's and 'O's. Can readers get the proper effect?

Thanks for all the other bits and pieces you sent Richard. All will appear over a period of time.

Will Watts, EUG #10

Richard Dimond