Fantastic!

I'm looking forward to playing with these. I bought some from SparkFun @ $4 each... our local MicroCenter here in Columbus, Ohio was out-of-stock already, but even at $4 it's a pretty good deal.

A little OT, but this reminds me of the HCF (Halt and Catch Fire) instruction on the 6800/6802/6808 processors (hex 9D) which continually incremented the address bus.

Good to know!

Josh's link took me to the Canadian Digikey site. I didn't notice at first that the price was $5.56 in Canadian dollars. The price on digikey.com, in USD, is $3.85. This is exactly what I've been look

If you blow up the picture a little, you see that we have a CHIP-8 program which draws the square. It would be nice to know more about this product.

What amazes me is, when I finally figure out what a problem was, it seems so obvious that I don't understand why I didn't figure it out a lot sooner. This seems to have been a pattern for me for decad

#memory #ELF

If I can jump in here, I think it was July, 1977, page 41: https://worldradiohistory.com/Archive-Poptronics/70s/1977/Poptronics-1977-07.pdf greg AB8IM

Also, a very pretty white and gold Harris 1802 from the same seller, same price. ========================================

Robert, this is very cool. Fortunately, the SpeakJet chip is currently available from SparkFun for around $25.

Ray, that was very generous of you! There's no doubt they were worth far more than you sold them for.

OS programming vs user programming: Mike, I agree with you, if, as a user, your code is bumping up against the size limitations of a data type. On the other hand, when you're writing an OS, I think yo

My Dad worked with a computer which used a sign bit for integers. This led to two representations for zero: a positive zero and a negative zero. He left it as a puzzle for me, how to tell the differen

Mike, that's what I'm used to as well, but it can cause complications; for example, it breaks the absolute value function, since the negative value exists, but the positive does not. I think if I were

Oops, David Madole had already explained this, and more concisely too. My bad. greg AB8IM ================

Craig, you might want to research "two's complement". When you subtract hex 10 from hex 05, it is decimal 16 subtracted from decimal 5 which is decimal -11 which would be -0B, not -0A. The answer woul

Lee, 3's complement is a new one for me.

Hello Todd, Thank you very much, I appreciate your kind offer. I really don't like asking other people to clean up my errors... this is the first time I've keyed in a source file that I wasn't able to

Herb, Comparing the object code in Ed's UT-62 RCA listing to your "ut62_herb.hex" file, the files are very similar, but do appear to be to be 5 differences, as shown below: Hex address, RCA code, your

ED, I can't speak to the interest part, but as far as your UT62 scans, they were awesome, perfectly readable. I'm about 55% finished typing out (transcribing) the UT62 source code, should be done by t