8 Mar
2012
8 Mar
'12
2:11 a.m.
On 3/7/2012 7:58 PM, Rick Bensene wrote:
* Don't have the ability to perform Boolean logic
operations
(bitwise AND, OR, NOT and derivatives) as built-in functions.
I t could do register
compares and other logic related to calculation steps
* Typically do not have the ability to manipulate
text.
It was fully equipped in the arithmetic department with operations and
branching.
* Typically does not have much in the way of main
storage. In
terms of K-bytes of memory, most programmable calculators from this
period max out at around 2K. Many machines had much less than this.
In 1963 a 1403
4k memory module cost $250,000 to a friend who was
implementing a
fore-runner to Ticketmaster, automating a group of manual answering
services to have
a central location. The cost of memory was nowhere near what it would
be a the end
of the decade, and would blow the budget for any device that was
"personal" if it had
much.
* Output is in the form of numeric display (CRT,
numeric indicator
tubes(Nixie, Panaplex, VF, LED); limited function output printer
(numeric and function annotation); or both.
output was mostly on adding machine
paper for me.
* Programs were initially entered via learn-mode,
where the
operations provided for by the machine's keyboard were stored into
program memory as "steps". No "language" per-se, just keyboard
operations.
No the operations were more complex than just hitting keys. There were
a number of mode
to take into account when doing programming.
* In most cases, programmable calculators can't do
self-modifying
code (though there are a few exceptions where program step and register
memory are overlapped)
*
I recall doing exactly this, modifying a program. The register and
programming memory
was overlapped and could be modified while the program was running. I
did just that as
mentioned just to do so.
On a device with so few resources there was not much one could do.
Recall that there was 256 bytes (if memory serves) of ram on the Atari
2600. It had lots of
program storage, none easily modified, but only a couple of orders of
magnitude more storage
than the 101 did. Admittedly there is way more to the story, but I
don't agree with the subjective
bits of size, etc. Architecturally this was a computer, not just a
calculator.
I just wish mine worked. The one I have locks up and doesn't run, sad
to say, gets the red warning
light and stops. Someday hopefully I'll get the time and bravery to fix it.
Jim