PC-SPITBOL for Intel 8086 DOS Now Available

I just located my copy of PC-SPITBOL for the IBM PC, 8086, circa 1983. This is a 16-bit version.

It can be downloaded here.

Here are some pictures of the manual and a screenshot showing PC-SPITBOL starting up:

PC-SPITBOL Manual, 1983

I did comparative runs of PC-SPITBOL 8086, SPITBOL/386, and CPython, using Cygwin on Windows XP:

CPython 55 seconds
SPITBOL/86 15 seconds
SPITBOL 8086 22 seconds

The numbers speak for themselves. PC-SPITBOL, written in 1983, is almost three times faster than CPython. SPITBOL/386, created over a decade ago, is more that four times faster than CPython.

Screenshot showing comparative times

Here are the test programs:
Python:

def add(a,b):
 return a+b
def sub(a,b):
 return a-b
n = 0
limit = 1000000
limit = limit * 50
trips = 0
for i in xrange(0, limit):
    m = add(n, 1)
    n = sub(m, 1)
    trips += 1

PC-SPITBOL, 8086, 16-bit:

 &stlimit = -1
 define("add(a,b)") :(add_end)
add
 add = a + b: (return)
add_end
 define("sub(a,b)") :(sub_end)
sub
 sub = a - b: (return)
sub_end
* repeat for limit1 * limit2 * limit3
 n = 0
* limit = 1000000
* limit = limit * 50
* variant for 16-bit spitbol, need to keep numbers small
 limit1 = 10000
 limit2 = 100
 limit3 = 50
 trip3 = 1
lp3
 trip2 = 1
lp2
 trip1 = 1
lp1
 m = add(n, 1)
 n = sub(m, 1)
 trip1 = trip1 + 1
 le(trip1, limit1) :s(lp1)
 trip2 = trip2 + 1
 le(trip2, limit2) :s(lp2)
 trip3 = trip3 + 1
 le(trip3,limit3)  :s(lp3)
 output = limit1 " " limit2 " " limit3
end

SPITBOL/386, 32-bit:

&stlimit = -1
 define("add(a,b)") :(add_end)
add
 add = a + b: (return)
add_end
 define("sub(a,b)") :(sub_end)
sub
 sub = a - b: (return)
sub_end
 n = 0
 limit = 1000000
 limit = limit * 50
 trips = 0
lp
 m = add(n, 1)
 n = sub(m, 1)
 trips = trips + 1
 le(trips, limit) :s(lp)
 output = trips
end

There is a bug in the “sourcecode” function in that right parenthesis followed by a colon is deemed to be a “smiley face” and so rendered as an image. I find this so charming that I have left it in.