Also from Ron Mak: "Note that you cannot use the card deck output from the Autocoder assembler directly as input to B1401. You'll have to create an appropriate character map first, and I didn't play with it long enough to figure out how to do that."

From Ron Mak

Unzip the attached file 
   [ or on Randy Thelen's machine in
       http://www.madscientistroom.org/ethelen/
     see autocoder-van-ron-05-01-04.zip
   ]
into a directory, and you will find 
autocoder.exe and i1401.exe (the SIMH 1401 simulator), 
along with my programs pi1c.s and pi5c.s.  You can edit 
Autocoder source programs with your favorite text editor, 
or even with editors you don't particularly like.
 
Here's a sample session.  The autocoder program reads pi5c.s 
(the source program) as input and creates the object card 
deck pi5c.cd and the assembly listing pi5c.lst. 

 Next, in the simulator, attach the card deck pi5c.cd to 
the card reader and attach the output file pi5c.out to 
the line printer.  Then boot from the card reader.  
   [see  SIMH documentation by Bob Supnik ]
        SIMH Help file

The program runs until the final halt instruction, and 
if you continue from there, you'll see that it branches 
back to the same halt instruction (as per the program).
 
You can set the CPU (actually, memory) display to hex, 
and examine memory.  
For each memory location, the right hex character is the 
BCD character, and the left hex character is the word mark 
and zone bits.  

For example, 48 is the character 8 with a word mark, 
and 3A is the character 0 (2-8 punches) with the plus sign 
(11-12 zone punches). 
 
Quit the simulator.  
Display the contents of the output file pi5c.out.
 
C:\IBM1401\test>autocoder -b I2 -o pi5c.cd -l pi5c.lst pi5c.s
    [for a meaning of the parameters, click here]

C:\IBM1401\test>i1401
    [SIMH documentation by Bob Supnik]
IBM 1401 simulator V3.2-3
sim> at cdr pi5c.cd
sim> at lpt pi5c.out
sim> b cdr
 
HALT instruction, IS: 953 (H)
sim> c
 
HALT instruction, IS: 953 (H)
sim> set cpu hex
sim> e 310-319
310:    48
311:    03
312:    0A
313:    01
314:    01
315:    09
316:    04
317:    09
318:    01
319:    02
sim> q
Goodbye
 
C:\IBM1401\test>type pi5c.out  
   [extra linefeeds added by Ed Thelen]
     ***** PI TO 500 DECIMAL PLACES *****  
 
 0001:  3.1415926535 8979323846 2643383279 5028841971 6939937510 
          5820974944 5923078164 0628620899 8628034825 3421170679
 0101:    8214808651 3282306647 0938446095 5058223172 5359408128 
          4811174502 8410270193 8521105559 6446229489 5493038196
 0201:    4428810975 6659334461 2847564823 3786783165 2712019091 
          4564856692 3460348610 4543266482 1339360726 0249141273
 0301:    7245870066 0631558817 4881520920 9628292540 9171536436 
          7892590360 0113305305 4882046652 1384146951 9415116094
 0401:    3305727036 5759591953 0921861173 8193261179 3105118548 
          0744623799 6274956735 1885752724 8912279381 8301194912
 
The simulator also has single-step and breakpoint commands. 
The h command prints a brief help message for each of the commands.  
Sorry, this is all command-line stuff without a fancy GUI.  
But have fun!
 
-- Ron
 
Ronald Mak
University Affiliated Research Center (UARC)
University of California at Santa Cruz
Mail Stop 269-3
NASA Ames Research Center
Moffett Field, CA  94035-1000
 
Office: (650) 604-0727
FAX: (650) 604-4036
rmak@mail.arc.nasa.gov
 

Just a small adjustment to your instructions:
 
From DOS box:
    Go to directory in which you Unzipped the file.
    at prompt enter:  autocoder -bI2 -opi5c.cd -lpi5c.lst pi5c.s
 
The spaces threw me for a loop.

You can also examine memory similarly to how the 1401 hardware 
would dump it, or many dump programs would dump it: As BCD with 
word marks under it.

Use the -d option for the "examine" (e) command, 
     e.g. "e -d 310-319".  
The hyphen can alternatively be a colon.  You can also ask for 
a disassembled version of the code by using the -m option, 
     e.g. "e -m 4297:4300".  In the
current version of simh, invalid instructions or invalid 
instruction lengths cause trouble.  In the next version, 
length-three fields will be displayed as DSA, which will decode 
the address to decimal.  Other invalid lengths, 
and invalid op codes, will display as DCW @...@ in BCD.

Unlike a 1403 with A or H chain, simh shows every character 
in BCD (except for blank, of course).  

Here's the translation table:

char bcd_to_ascii[64] = {
          ' ',   '1',   '2',   '3',   '4',   '5',   '6',   '7',
          '8',   '9',   '0',   '#',   '@',   ':',   '>',   '(',
          '^',   '/',   'S',   'T',   'U',   'V',   'W',   'X',
          'Y',   'Z',   '\'',  ',',   '%',   '=',   '\\',  '+',
          '-',   'J',   'K',   'L',   'M',   'N',   'O',   'P',
          'Q',   'R',   '!',   '$',   '*',   ']',   ';',   '_',
          '&',   'A',   'B',   'C',   'D',   'E',   'F',   'G',
          'H',   'I',   '?',   '.',   ')',   '[',   '<',   '"' };

The bit order to index the table is BA8421.  
       So group mark is 63, or ".

As of v3.3-0 there's also an instruction history.  I added logging, 
but I don't know if Bob Supnik has added that to the distribution.  
Try "set debug " and see if it logs everything, 
including details of instruction execution.

I've also added column binary I/O, but not Move-and-Binary-[De]Code,
but I don't know if that's in the distribution yet, either.

simh can do lots of other things, 
   like stop at breakpoints and single-step.
The source archive has the documentation.  Get the source from
   http://simh.trailing-edge.com/.

-- 
Van Snyder                    |  What fraction of Americans believe 
Van.Snyder@jpl.nasa.gov       |  Wrestling is real and NASA is fake?