Isn't that one of those tricky entry points?

Valid to enter at 6F58 and  6F52.

Mvi a, 03 in each case.

On Friday, April 10, 2026, Kurt McCullum <[email protected]> wrote:

> Thanks Ken,
>
> I do have an example.
>
> 1. Put a breakpoint at 6F58
> 2. Go to TELCOM and type TERM
> 3. Look at the Instruction Trace. It will say 6F58s MVI A, 03H
>
> 4. Go to the ROM source listing.
> You will notice there is no command at 6F58H. Instead it says
> ; ======================================================
> ; Initialize RS232 or modem
> ; ======================================================
> 6F52H  (3EH) MVI A,01H
> 6F54H  (01H) LXI B,023EH
> 6F57H  (01H) LXI B,033EH
> 6F5AH  (E5H) PUSH H
>
> To me it looks like the debugger got off track at the bottom of the ROM.
>
> Kurt
>
>
> On Fri, Apr 10, 2026, at 3:06 PM, Kenneth Pettit wrote:
>
> Hi Kurt,
>
> Umm, I believe the disassembler *should* be looking at the ROM if I
> remember correctly.  Could just be a latent bug.  Do you have examples of
> discrepancies?
>
> Ken
> On 4/10/26 12:35 PM, Kurt McCullum wrote:
>
> I am running into a problem with the disassembler for the main ROM in
> Virtual-T for the NEC 8201a.
>
> In particular, the RS232 initialize routines don't match what the ROM and
> debugger show as far as code.
>
> For the main ROM, is the disassembler actually looking at the ROM, or
> something else?
>
> Kurt
>
>
>

Reply via email to