Why blinkenlights ?

[Allison]

>
>Subject: Why blinkenlights ?
>   From: Jos Dreesen <jos.dreesen at bluewin.ch>
>   Date: Tue, 20 Mar 2007 21:18:40 +0100
>     To: cctalk at classiccmp.org
>
>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...
>
>
>So why is it then  that almost all early micros had them ?
>
>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 ?
>
>             Jos

For it's era it was low cost (compared to 1702 Eproms) and it provided the 
ability to debug the hardware. Also t was flexible as it was both IO and
allowed program entry and crude debug (single step). Early systems also 
lacked software to interact with and often what was available had the 
have the IO altered for to match the available IO.  This was very true 
for the 8008 generation and remained true for the early 8080 generation.

Later systems such as the H8 were better but also really represented a new
subspecies of systems leading to the turnkey based systems.

Personally I felt it was the first 6800 (and 6502) based systems that 
made switches and lights outmoded by using a standard console IO and 
a rom based monitor program to do the functions that a hardware front
pannel provides.  By then ROMs/Eproms had dropped in price and the hardware 
saved was enough made it far less expensive.


Allison