Inspection and cleaning:
Lots of modifications to the Giant Board, mostly in back-side modifications that brought power out to the I/O port headers. All of that was removed and the board restored to factory configuration. C1 had been replaces with a .1uF and C4 was cold soldered and it's leads moving within the solder joints. Both C1 and C4 were replaced with .15uF caps, per factory specs. All jumpers were also returned to factory specs.
Testing:
The Giant Board was tested by:
- Launching the on-board monitor at 0xF000 successfully.
- writing a cassette file
- reading a cassette file ... although this fails for me since I have a very noisy cassette player!
- reading, writing, searching, and launching programs in memory all successful.
- I wrote a simple program to read the input port and tested each bit.
- I wrote a simple program to write to the output port and tested wach bit.