OpenEuphoria

Re: A contest...with a prize!

• Posted by mountains at MINDSPRING.COM Jun 03, 1998
• 1031 views

At 12:04 AM 6/3/98 -0400, Jacques Deschenes wrote:

>This is code for RCA CDP1802 microprocessor.  The computer was probably a
COSMAC ELF
>Popularized by "Popular electronics" in 1977 (or 1978).
>I don't understand yet what is does. (what device was connected to output
4, line Q
>and input line EF4 ? )
>On my machine there was a LED on the Q line so codes 7B and 7A was flashing
de LED.
>I connected a speaker on that line too and  produce sound effects with it.
>I even code a program to play tunes.
>---
Hoo! I didn't expect a reply so quickly.
You are correct (enough to win the prize - where shall I send
the coupons?)

I wondered if there was a "signature" in the machine code
that would be recognizable, and sure enough, there was -
strange how some things stick in your memory, even for 20
years.

This ran on an ELFII, which had a 2 hex displays connected
to output port 4 (64), a hex keypad, and an Input key
connected to input 4.

There was also a relay driven off the Q line, which supplied
110v ac to a device.

If you're interested in a perfect, working 1802 computer in
hirez graphics: Quote: "Compatible with Windows 3.1, 95, and NT,
as well as WABI (Sun), WINE (X-windows), SoftWindows (Mac),
and other  Windows emulators. (And if you don't think it's
ironic to run a simulation of a 14-year-old microprocessor under an emulator
of an 8 year old operating system running on an expensive new personal
computer, then your sense of irony is obviously in
need of a checkup! "
>---
>---

Regards,

Irv