[sdiy] 8080-based synth reliability

[Ullrich Peter]

Yeah, we also used the Micro professor to learn Z80 assembler coding at school...

And I should still have a Signetics Instructor 50 laying around... but never used it by myself...
It has been clocked with 600kHz if I remeber correctly :-)
https://www.youtube.com/watch?v=vK34W8wexvI

Ciao
Peter

http://www.ullrich.at.tt 
________________________________________
Von: Synth-diy [synth-diy-bounces at synth-diy.org]" im Auftrag von "Michael Zacherl [sdiy-mz01 at blauwurf.info]
Gesendet: Freitag, 06. Oktober 2017 22:52
An: Synth DIY
Betreff: Re: [sdiy] 8080-based synth reliability

> On 6 Oct 2017, at 22:07, Ove Ridé <nitro2k01 at gmail.com> wrote:
>
> You ought to document the project for posterity and 5 minutes of Hackaday fame. If you post a ROM dump or perhaps source code if it survived for all these years, the project might take on a modern life on its own by dedicated hackers. (I for one wouldn't mind looking at it.)

Oh boy, I love this kind of synchronicity!
The other day I dug up my old original MPF-1 to show the students:

https://en.wikipedia.org/wiki/Micro-Professor_MPF-I#/media/File:Mpf-I.jpg

Dave, your posting definitely brings back old memories! :)
Very inspiring!

m.

> On Friday, 6 October 2017, Dave Brown <davebr at modularsynthesis.com> wrote:
> This is definitely DIY related and somewhat synth related in that it is a digital 3 voice synthesizer.  In late 1976 I designed a dedicated 8080 based three voice PWM synthesizer as a doorbell.  The code was based on a program called Music for the Processor Technology Sol-20 computer.  I had to disassemble the program to get it to run on a basic 8080 system using a single 2708 EPROM and two 2114 static rams.  It used a simple transistor driver for the speaker.  The 8080 is unmarked so I think it might even be an engineering sample.
>
> This system has continuously run for approximately 14,870 days or nearly 356,880 hours.  Well this week it died.  The processor is just absolutely lifeless.  I had another 8080 from the same vintage but at least marked and replacing it brought the system back to life.  Note that in the 40 years the 2708 has not forgotten even though the guaranteed retention is only 10 years.  I think it will outlive me.
>
> It was a really progressive program for the time.  This doorbell also includes a RS-232 interface so I could compile new music to upload to it for special occasions.
>
> Dave

--
http://mz.klingt.org


_______________________________________________
Synth-diy mailing list
Synth-diy at synth-diy.org
http://synth-diy.org/mailman/listinfo/synth-diy



The information contained in this e-mail message is privileged and confidential and is for the exclusive use of the addressee. The person who receives this message and who is not the addressee, one of his employees or an agent entitled to hand it over to the addressee, is informed that he may not use, disclose or reproduce the contents thereof, and is kindly asked to notify the sender and delete the e-mail immediately.