COSMAC 1802 Simulator - test-drb@ccmp.vtda.org

4 May 2000

Hi,  (comments embedded below)

From: allisonp(a)world.std.com &lt;allisonp(a)world.std.com&gt;
...

Havent played anything hard on it to test if it is a valid 1802 but I have
comments and suggestions.

 Build it as a basic engine, if it needs ram then set a external parameter
 list for how much and what addresses, same for rom. 

Yep, in there from the beginning.... maybe for multiple instances of cosmacs
'linked' to each other or at least as a few depositable c++ classes that can
be that generic engine..  But I didn't consider the "Load List" idea for
[all] individually specified ram and rom blocks to define a 'complete
system'.  *snag*  ;)  Thanks.  This LL should probably also specify any
additional 'hardware' thrown in (uart, parallel interface( probabbly
necessary to simulate a cosmac disk drives and raising CDOS in the emulator
(final goal)), etc)

...
  Simulate IO, if it has a uart on the N-lines then
create the
 registers/data you interact with (or the Q and Sense lines). 

I'm reviewing the CDP1854 uart specs and a UT21 rom listing now and will add
it shortly.  I need UT4! ( and UT3, etc... )

...
 The console can be like the ELF (switches and lights)
and/or
a RS232 tube connected via Q and F lines, software uart required
as part of the code as UT4 does.

 Load UT4 (or whatever) from a start up list to emulate the rom
 and have the 1802 engine execute the "rom" cone out of memory space.
 This would allow code to "call" various ut4 routines like get or type.

 The miniassembler is nice and plenty handy.  You may want to consider
 having it run like real code loaded into ram later on. 

Thanks. And I see your point

...
  The core of the instruction set is fairly regular so
the select tree
 can be broken into functional sub trees for simpler code.

 The version of TB I have is quest TB and I don't have it on machine
 readable form (other than papertape which I currentlly can't read)
 so I'd have to copy the pages and someone can have the fun of toggleing
 it in, it'a about 1k or 2k. 

Somebody else has been there done that.  Thanks Kirk!

Thanks for the suggestions, Allison!  More soon.

:)
- Mike: dogas(a)leading.net

...
 Allison

On Wed, 3 May 2000, Mike wrote:

> Tonight I added the mini-assembler and memory block saves&loads to the
1802
...
   simulator. 
The 95/98/nt console binary and source-code are at:

     http://users.leading.net/~dogas/classiccmp/cosmac/vcosmac.htm

 Allison

Good runs under W95/nt then, have that running.
M!... Ah UT4.  have manual. 
 heh.. early influences...

 Wheres Bin/CPP for it? 
 Up there.

 Let me know if it doesn't do what you think it should.

 Thanks
 - Mike: dogas(a)leading.net

Last emulator for 1802 I'd played with was z80 based, even on a 4mhz z80
it was faster than 1802.  I wonder where I put that.