HPASM was obtained from http://oscar.taurus.com/~jeff/2100/index.html
and assembled for Windows using LCC (I think... been awhile).

HPASM has problems with some compound instruction combinations,
when it happens the first letter of the instruction is replaced
by a space. Use HP-IPL/OS' CREATE or OCT_TOOL to derive the
correct octal code and replace problem compounds with OCT lines.
Seems both CREATE and OCT_TOOL can get it wrong at times so it's
probably a good idea to get multiple opinions, if any doubt pack
the instruction bits manually. HPASM does not support extended
math or DMS instructions, encode these as OCT statements.
Despite a few minor problems, HPASM is the only game in town
for assembling HP21xx code on a PC.

HPASM accepts a source filename on the command line and outputs
hpasm.lst assembly listing and hpasm.out ABS-encoded binary.
Renaming files is tedious, I like to right-click and assemble
so I wrote MPA.BAT that renames the output files in accordance
with the input file. To right-click and assemble HPA files use
Windows' file type dialogs to add an assemble option for .HPA
files that runs MPA.BAT, or use at the dos command line, MPA file.

----------------- cut, MPA.BAT ------------------------------
:: MPA.BAT by Terry Newton  1/13/02
:: Runs the MPASM 21xx cross-assembler and renames the
:: output files to match the source name. Drag-n-drop capable.
:: If no parameter or non existing file specified, lists directory.
:: Requirements... nothing special but %temp% variable must point
:: to a writable directory - creates, uses then deletes temp com
:: and batch files for parsing the parameter into directory, base
:: and extension components. Take care not to alter the binary parts!
:: Output .out and .lst files created in the same dir as the source.
:: If no extension specified defaults to .HPA, edit batch to change.
@echo off
if .%1==.Shell goto %1
%comspec% /e:32768 /c%0 Shell %1
goto end
:Shell
:: change dir-list extension as needed...
set default_ext=HPA
:: --------------------------------------
:: list directory if no parm specified...
if .%2==. goto listdir
:: temp filenames...
set tf=%temp%.\_mpa.tmp
set dec=%temp%.\_dec.com
set sepname=%temp%.\_sep.com
::-----------------------
:: CM3-encoded DecBin decoder...
ECHO:`h}aXP5y`P]4nP_XW(F4(F6(F=(FF)FH(FL(Fe(FR0FTs*}`A?+,>%dec%
ECHO:fkOU):G*@Crv,*t$HU[rlf~#IubfRfXf(V#fj}fX4{PY$@fPfZsZ$:NvN$>>%dec%
ECHO:9AyroNB-)dOKwK0rRkfTbi)ws_~[[q9wE'sqlu1sY*Bsfe=@ziNS1a)88e>>%dec%
ECHO:f9RTL)9Z{3INBD?o6@MDLO{Zz4Q23E-'09NX9@Vz(42A7c8zMS:u$w6k5Q>>%dec%
ECHO:N,h:le)~gF?tutTyxoe5UiIdtn';0rJ1q:{7;lAl']y:yTjZBbOo?QRIdN>>%dec%
ECHO:$Bp@P/nAp_r0*4f'XcF4q3o?$_t5lx$Q-OxSfUNQ__Gd~$Q-Oxgkx=LGHU>>%dec%
ECHO:S)$C6P8#>>%dec%
::---- EncBin-encoded binary ----
:: sepname.com made with BASM ASM FREELINK
ECHO:AEPPr64U2y00tD61O0AAj7CDXn28A5S5D7JeRkl5Ll00xG47uvgmv5gl[5>%tf%
ECHO:gGC0v]U[2uY7213301EBu1Je13dnJDrX5OIZO5QZO5ibr1Vbj3AxS5Ayv6>>%tf%
ECHO:Zb02ibf3Axv6Rbf2RbC2Ayv6Jbf3abb3Axv62yK6ebr12rK6ZbC2ib42Ay>>%tf%
ECHO:v6ab[3Axv6Eyj5Rb42Dn3e0J]xN53b8l3b6l3bB\2jG0gC7DB7n6j50037>>%tf%
ECHO:v6j5000mF0cdr5ilW6tfC106Ld2ZNH37C6n5003yC6n5EXn5Ou3Hr5S3Fe>>%tf%
ECHO:IGebC3Axv6EXn56u00qbC3ybb1EyG7qb83ExG7Myn5ebb1Dn3e07]XNJ2Z>>%tf%
ECHO:ND2xT32yNN3b6M1nf3r76GeJC5eFf5thpXj5Ou3Fv5S3Ve2GR73F0500Rb>>%tf%
ECHO:r2]xn5Iy[7Vb81ebn2Axv6Myr7ib41ubj2hxn5QyC8yb01t3FF451yf3s6>>%tf%
ECHO:EGF0O33FK53yFyeTW5tfv2vpNT1bRl3b933b4Z2yV\3bAX0mF006NH0ev6>>%tf%
ECHO:j5pZn5abW2RyFTW5RlW6rrW2r0v1fpW8sxC2WxND01Dy3e1I]XND2ZNT3b>>%tf%
ECHO:9Z3ynpn59bv6ebv1ebn0Iy[7ZbK20mlZLd2xV\3b2N03b6O5pZn50mj3n6>>%tf%
ECHO:n5Oe3DC5eTW5rhv2vpNT1bV\3b7T3b2\2yV\3b8Z1bNV3b8s1bUK3b8m1b>>%tf%
ECHO:LR3b8g1bNd3b8a1bV\3b8X1bLR3b8R1bNo3b8L1bWp3b8F1bLR3b892n9C>>%tf%
ECHO:F07DAn83Fy3D4me0Z23xlZLI2Au6y0IZK5i3WMLI3x7AcKb5Zjuxlnn2jG>>%tf%
ECHO:m3xfdd30coy3PHLNtBvla0iymyylUhyHg9Z1sVLP73LNPMLNXUuXiyZOXU>>%tf%
ECHO:uRiyZ8s1LVf3yvRmA[DPlxPG2yNy3byRy3TGLMmvdhHo0AN0VrwULOi3Zr>>%tf%
ECHO:6sK0ivZqlfD1Pl0vwQS20ftdBYy3ebaygGZ8]3v0gxEBOUK5IXK5tBDIr5>>%tf%
ECHO:46w8I33y1yC2Fy2tK0Bqr37rqa2r2j2ElnnFjGSv1nW5f0trZ0Jvb]p857>>%tf%
ECHO:ZYv7WVK186K5y3hXW6s3uyhXW6ryr0gGv6hXW6rnuyhXW6r1C0lyQX3bva>>%tf%
ECHO:xxQX2yPG3bvUxxPG3bvWxyPG2BF83rpA603u9yCBF0M819DFZsn0Vhy3hX>>%tf%
ECHO:W6uruxhXC6F9l0CWTo16D1ZsLHVn6sK02yK6Fvv]E[m786K5013yG6K5t3>>%tf%
ECHO:DKb55ov4vELK2tLO2nn9jXtB5Ib5ZJexlBGUK5EAyxFEFRAn3DCGkLlBtB>>%tf%
ECHO:Hp2yPG2BPE3vRmA[0ml8n5N2041LlBt3Bf0ma0X6ixXpW4t8ix9606I9s6>>%tf%
ECHO:vw001wW6f1[0X6yxgGO6j5f0Xpv4gGC61puxIs1H0esEyvRmA[0ml8f5Z\>>%tf%
ECHO:9Tj4v0iyC5F0M933xxv5mbFxF3LGmbuyyvgGW6K3ujHPRmA[N600N3MBif>>%tf%
ECHO:XpW4r\ixZ86u00QBK42nJDnXN202014000070DGA8D0A07000000000000>>%tf%
ECHO:0000000000000000000000000000000000000000000000000000000000>>%tf%
ECHO:0000000000000000000000000000000000000000000000000000000000>>%tf%
ECHO:00000000whOW5jPl1g0000000000j0K00h000000001mH\SW1]TXXnOwC0>>%tf%
ECHO:T\1n9]5YPmo\C0LmPnOWP\HrSwn0}>>%tf%
:: BASM source...
:: rem separate specified name into fpath,fbase,fext
:: rem outputs sets to stdout
:: $com
:: a$=command$:a$=trim$(a$):a$=lcase$(a$)
:: if a$="" then
::  print "no parm":end
:: endif
:: rem loop through string, mark last \ and .
:: slash=0:dot=0:ilen=len(a$)
:: for i=1 to ilen
::  c$=mid$(a$,i,1):if c$="\" then slash=i
::  if c$="." then dot=i
:: next i
:: rem not an extension if \ after .
:: if slash>dot then dot=0
:: fpath$="":fbase$=a$:fext$=""
:: if dot>1 then
::  d=dot-1:fbase$=left$(a$,d)
::  d=ilen-dot:fext$=right$(a$,d)
:: endif
:: if slash>1 then
::  rem includes trailing \
::  d=slash:fpath$=left$(a$,d)
::  d=len(fbase$):d=d-slash
::  fbase$=right$(fbase$,d)
:: endif
:: output "set fpath=";fpath$
:: output "set fbase=";fbase$
:: output "set fext=";fext$
::-------------------------------
:: decode and use _sepname.com to parse input (in %2)
%dec% < %tf% > %sepname%
%sepname% %2 > %temp%.\_sep_tmp.bat
call %temp%.\_sep_tmp.bat
del %temp%.\_sep_tmp.bat
del %sepname%
del %dec%
del %tf%
if .%fpath%==. goto incurrent
:: change to source directory
%fpath%
cd %fpath%
:incurrent
:: add extension if not specified...
::---- put commands here...
:: %fbase% = base name
:: %fext%  = extension (no dot)
:: %fpath% = path (ends in \)
:: %2      = name as entered
:: current dir is where the file is
::---------------------------------
set filename=%2
if exist %filename% goto fileok
set filename=%2.%default_ext%
if exist %filename% goto fileok
echo File not found. List...
goto listdir
:fileok
hpasm %filename%
copy hpasm.lst %fbase%.lst >nul
copy hpasm.out %fbase%.out >nul
del hpasm.lst
del hpasm.out
::---------------------------------
choice /c:q /t:q,2 >nul
cls
goto end
:listdir
dir /p *.%default_ext%
:end
----------------- end of MPA.BAT ----------------------------

9/6/04 Terry Newton