23 Oct
2005
23 Oct
'05
9:49 a.m.
On 10/22/05, Martin Bishop <mjd.NO.bishop.SPAM at iee.org> wrote:
QUOTE The 8/A cannot have an EAE UNQUOTE
Don't think this is correct. Because, such a machine would have no serious
(integer) arithmetic capability.
The -8/a wasn't always sold to the same crowd as the -8/e. Lots of
-8/as were used for WPS/8 (the "DataSystems 310" package, for
example). Never doubt that Marketing is capable of selling systems
that aren't "serious". In any case, not everybody needs an EAE - I
myself have been using PDP-8s for 23 years, and with the sole
exception of wanting to put together a 12-bit SPACEWAR machine, have
never come close to needing an EAE.
There was an FPP-12 for the KK8A, but they were expensive (by PDP-8
standards) and rare (and not software compatible with the KE8E). If
you _really_ needed to boost FORTRAN performance, you had that option,
but to my recollection, it wasn't an ordinary add-on.
Also, the PDP 8/A Minicomputer Handbook
1976/77 has a lengthy section [pp9-56 .. 9-65] on the KE8-E (Extended
Arithmetic Element : EAE). However, the "PDP-8 Summary of Models and
Options" (posted by Doug Jones) indicates that the EAE can be fitted iff the
PDP-8/E CPU boardset is fitted. That is PDP-8/A models 600/620 were fitted
with the KK8E CPU and optionally the 8/E EAE. And, I imagine "field
specials" were doubtless built.
Another wrinkle; correction invited.
OK... to be pedantically specific... the KK8A CPU cannot have an EAE.
It's a single hex card with no "over the top" fingers to attach an EAE
to. I can't speak for the original poster, but frequently, folks
conceptually lump together the box name "PDP-8/a" with the most common
(of its day) CPU "KK8A" and thus the original statement is seen from
time to time.
-ethan