On Tue, Apr 23, 2019 at 8:25 AM Patrick Finnegan <p...@vax11.net> wrote:
> On Tue, Apr 23, 2019 at 11:02 AM Jon Elson via cctalk < > cctalk@classiccmp.org> wrote: > >> Is the ROM totally bad, or just losing a few bits here and >> there? If the latter, you could probably read it out, figure >> out how the rows, columns and characters are mapped, and fix it. >> > > Considering that 925s are really common, and a replacement EPROM should be > easy to source and program, this sounds like an overly difficult approach > that will yield something different than what he wants. > The thought had crossed my mind, but only as a last resort. I'm not entirely sure what the internal fault is, but the end result is two rows of every character have all bits stuck "on." I've verified that the ROM addressing is correct and that there's nothing on the output side causing this behavior. Patrick, thanks very much for offering to read the ROM! - Josh > Pat >
