b9,
Is the Televerket ROM available online somewhere?
Ken
On 4/6/26 11:46 PM, B9 wrote:
Following John's hint, I was able to figure out the backwards writing
problem. It turns out to be a bug in the original Norwegian RxHandler
code from INSTAL.BA which was enabling interrupts (EI) before jumping
back into the ROM's handler. Replacing the EI instruction with NOP
fixes it.
I look forward to hearing if files sent to TELCOM show reversed words, if
they do, then my patched INSTAL (below) should fix it. To get higher
speeds
with retro equipment you need a better USB to serial converter. It has to
have "on chip XON/XOFF", but that's rarely mentioned on the packaging.
Look
for "FTDI" or "FT232".
As for the missing line drawing characters, you actually have most of the
characters I've seen used in games. Try that FOR loop again, but starting
at character 128 and you'll see what I mean. All you'll be missing are
blocks and boxes like this:
[image: How to type in Virtual T using a Norwegian ROM]
—b9
