Posted By
JamesC
on 2007-04-21
15:16:55
|  Re: @ characters on screen upon bootup
NTSC Plus/4 will have a 1.843MHz crystal at Y2 (to the right of RAM). PAL crystal will be a different value. Usually the value is printed on the crystal's housing.
One may try to fake an NTSC machine by putting an NTSC Kernal in U24. What is the MOS number of your U24? 31800x-xx
Test the 1551 on another TED machine, or test the DIRECTORY listing using a serial drive (1541, 1571, etc). I have 2 1551s that behave as yours does and I cannot find any problem in them.... and nobody seems to have any factory service manuals. YAPE will occasionally throw me the same problem with 1551 CPU emulation combined with NTSC, so I suspect there's a problem in the original engineering.
@ appearing on boot: press F4 or type SCNCLR (or Shift/Clear-Home). Do the @s go away?
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