Yesterday, I installed “TSim51-6.0.0.653-setup.exe” on my XP laptop then run “TSim51 HLL & Assembler”.

Its on-line help document gives the necessary detailed info about C51 hardware and firmware (assembly). But since I couldn’t find the help pages for the IDE, I had to discover its characteristics by trial and error.

When this IDE started, it displayed a note that some examples are created, on my laptop, in:

C:_Documents and Settings_MainBoot_My Documents_TAsm51_Projects_examples

So I made another folder to test my first asm.

C:_Documents and Settings_MainBoot_My Documents_TAsm51_Projects_I12VF_E7

And I copied into it my code file under test, I12VF_E7.asm (for AT89C2051 which was assembled, after some modifications, by some C51 assemblers since I wrote it first, as all other ones during the last 20 years, for TASM on DOS).

After browsing, I opened it on the IDE window and tried to find out its possible syntax errors by running “Assemble using TAsm51”. I got:

“Access violation at address 0055924B in module 'TAsm51.exe. Read of address 00000008.”

My first thought was to find out which line (or lines) of the code that leaded to this quasi crash. So, I repeated its assembling after removing some parts of the code. But every time, I got this error message or, sometimes, the program crashes by staying in the status of compiling. This continued to happen even when there were just a couple of instructions, from org to end.

Fortunately, after about an hour, I had the thought to save the asm file under test (now very small) as a project. (To do this, I also learnt that the working folder should be set explicitly in advance, with its assembling output one as well). Then I pressed again, as the last try, on “Assemble using TAsm51”. "Et voila", things run as expected but I had to have a rest after this great discovery ;)

For instance, did I miss finding the help pages about the IDE of Turbo51 (mainly of TAsm51)?

Thank you.