Bottlehead Forum

Other Gear => Digital => Topic started by: Natural Sound on January 28, 2014, 12:10:43 PM

Title: Re: Taking orders :) - now Old Timey Digital
Post by: Natural Sound on January 28, 2014, 12:10:43 PM
     

               Question for John S:

           How do you prototype these days?
           
    When we were doing it (a long time ago) it was Augat wire wrap boards with DIP spacing for mostly 74XX logic parts . You could debug fairly effectively with a hand held Logic Probe.

             Seems that there is a totally different methodology required with what's available today.

I remember those days. My boss was cheap though and wouldn't buy me a wire wrap gun. I had the tool to do it by hand. As for circuit board layouts I used a light table, mylar and tape. Most boards were scaled 2 to 1. The board shop would reduce that and print the boards from there. Then we finally got a computer for CAD in the late 80's and that changed everything. OK I know I just revealed a little bit about my age.  ;)
Title: Old Timey Digital
Post by: pdxgrampa on January 28, 2014, 01:25:27 PM
As long as we revealing ages:

Machine language programming Intel 4004(4k address space) and 4040(16k address space) using a UVEPROM programmer.Write instructions in human readable and binary and set 8 toggle switches to represent the binary,increment the address counter and set the location X 256 for 1702  and 512 for 2704 PROMs.Debug and repeat the whole thing.
Title: Old Timey Digital
Post by: Paul Joppa on January 28, 2014, 04:36:52 PM
Hah - can anyone identify ForTransIt? Hint - it was a computer language. Yes I used it, it was my third computer language. Good luck.
Title: Old Timey Digital
Post by: RayP on January 28, 2014, 04:57:51 PM
I started on Fortran IV in my post grad degree in '69. We also learned PDP 10 assembler and Cobol. I can't say I was any good at coding back then but I did enjoy the logic. I can still remember sitting down at an 026 punch card machine for the first time and realizing that I had never learned to type. Needless to say, it was a slow process.

ray
Title: Old Timey Digital
Post by: John Swenson on January 28, 2014, 08:03:53 PM
I used to do wire wrap by hand for my own projects with the little tool.  In high school (mid 70s) I did a video game entirely out of 7400 stuff (about 60 chips), the output was color NTSC video. On Saturday my dad would take me to work where they had all the scopes and power supplies and stuff so I could debug it all. At one point I shorted something and dumped 30A at 5V through one TTL chip, it was fascinating to watch, the plastic on the top of the chip started bubbling, then it just exploded, filling the entire lab with black smoke, setting off the fire alarms etc. Boy was I in trouble!!

John S.
Title: Old Timey Digital
Post by: mcandmar on January 29, 2014, 02:17:23 AM
I started on Fortran IV in my post grad degree in '69. We also learned PDP 10 assembler and Cobol.

I learnt Cobol in college in 96!  Though i was more interested in how to use the VAX operating system than programming in cobol. I thought it was all a complete waste of time until i did a job interview for a network admin position and they asked "Any chance you know Digital VMS?"  i ended up looking after that system for five years running a sales system written in cobol :)

I kid you not, the backup ran onto a reel to reel tape system the size of a refrigerator, that server room was like stepping into a time warp.
Title: Re: Taking orders :)
Post by: RPMac on January 29, 2014, 08:56:37 AM
I come from the time of punch cards and reel to reel backup. I have not taken the time to learn the digital side of things, so this question comes from a place of ignorance.

My music is in iTunes with most being in Apple Lossless.

How important is the digital side going to be to the BH DAC?
Title: Re: Taking orders :)
Post by: Paul Birkeland on January 29, 2014, 12:25:49 PM

How important is the digital side going to be to the BH DAC?

It's a funny thing, this technically "shouldn't" matter, but it does indeed make a difference.

There's a lot of good reading on this here (http://www.computeraudiophile.com/forum/).