20 Mar
2007
20 Mar
'07
3:46 p.m.
On Mar 20, 2007, at 4:18 PM, Jos Dreesen wrote:
I am currenly contemplating what kind of IO to put on
my coming
i8008 system : what is it that makes blinkenlights (i.e. leds and
switches ) seem so attractive ?
It must be about the worst possible way to interact with a computer...
Uhh...they're *easy*.
So why is it then that almost all early micros had
them ?
Debugging. I've debugged a WHOLE LOT of code on my Imsai's front
panel in the mid-1980s. Nothing is simpler (IMO) as debugging via a
front panel
a 7segment display with keyboard ( as in a H8) is
clearly more
usable, and would have cost nothing more. Or were early eproms (for
the monitor program) that expensive ?
Well, there were no such things as EPROMs (or chips at all, for
that matter) on the earliest lights-and-switches machines. I think
single-stepping and debugging of very low-level stuff is much easier
with a lights-and-switches front panel. Numeric displays are nice,
but I find many keypad interfaces to be very cumbersome. The H-8
keypad is probably one of the nicest I've seen (it seems to make the
most sense anyway) but even it isn't as clear and unambiguous as "set
the switches to the address you want, and press 'load address'".
For today, though...blinking lights are Just Plain Cool.
-Dave
--
Dave McGuire
Port Charlotte, FL