review manual came bound with one of those pull-on plastic spines. I have no
objection to then, I’ve used them myself, but when I opened the manual I found
I could not read the start of most lines as they were lost in the binding.
Pulling the plastic spine off cured that, but then left me with a pile of
loose paper. My alternative method of storing manuals – four-hole punching the
pages and storing them in a ring binder – would not be perfect either, as the
holes would mutilate some of the text. I measured the left and right margins
at 10mm and 15mm respectively. I reckon they should be 15mm at an absolute
minimum, 20mm would be better.
On glancing through the Hisoft
HP5 manual one thing I noticed immediately
was that the range of the floating point numbers was given as 3.4x1038 to
5.9x10-39). However the range that the
can handle directly is only
9.2x1018 to 2.7x10-20. Subsequently I wrote a short program that verified that
the limits in HP5 are those of the Am9511.
The area where a product like this stands or falls is in how easy it is
to use. All your current software will obviously ignore it, and it is not a
trivial task to get round this problem. Belectra have taken a step in the
right direction by including in the price a special version of the Hisoft
Pascal compiler whose run-time routines make specific use of the arithmetic
processor. So if you want to “plug-in-and-go”, you are currently restricted to
Hisoft Pascal, or Pascal/MT+ which also has an option for using the Am9511.
Trying it out
I list below a few comparitive benchmarks of the performance. A nice
benchmark I came across recently  is a good test of processor speed and
accuracy on purely arithmetic routines. This very nicely matches the area in
would be used. Try it on your current favourite interpreter
and/or compiler for comparison with the figures below. Ideally it should
produce a result of 2500 in as little time as possible.
Fig 1 – DDJ Benchmark in BASIC
|Standard MBASIC interpreter||:||2304.86||in||225||secs|
|*||Modified MBASIC interpreter||:||2326.94||in||41.8||secs||Am9511||support|
|Hisoft Pascal (V5)||:||2326.94||in||29.1||secs||"||"|
|Simple assembly code||:||2326.94||in||26.8||secs||"||"|
|version of the benchmark||:|
* see below
Fig 2 – Benchmark timings (4MHz Z80)
Unfortunately several Pascals do not appear to offer TAN as a function,
(they do have SIN and COS), and only have ARCTAN for the inverse functions.
So, for the Pascals, I have translated the