Bill Mensch - Genesis and Evolution of the 6502 Family

Stephen Edwards and Bill Mensch - The genesis and evolution of the 6502 family
A presentation at Vintage Computer Festival West - August 8, 2021 - (VCF WEST 2021)

[@rabidbigdog]

Mensch (and team) and the 6502 is how so many of us got into computing. I will be forever grateful and STILL play with the 6502 to this very day.

[@vcfederation]

We appreciate what he did to help create this microchip.

[@tech5882]

His words "this is my life" are very touching. Great engineer and inventor who touched so many lives! Thanks Bill!

[@vcfederation]

Yes we appreciate his accomplishments and his humbleness. A great guy in person!

[@4youian]

Didn't commodore use the set overflow pin in the 1541 disk drive?

[@s3vR3x]

yes!!!!! thank you for releasing these in a timely manner. I missed part of sunday and its great going back and watching these

[@MarianoLu]

Must underrated video on youtube. What a legend!!!!

[@vcfederation]

Very great story about a great accomplishment.

[@jfwfreo]

The 6502 really did change the world. A 6502-based chip was used in the machine that really kicked off home video games (the Atari 2600) and again in the system that saved home video games (the original Nintendo). Many arcade boards used 6502s in various ways. Apple used the 6502 family. Commodore used the 6502 family. Atari used the 6502 family. The Acorn systems (including the BBC Micro) used the 6502 family. The PC-engine used a 6502 derivative.

[@vcfederation]

It's amazing how much influence that one microchip had in so many computers.

[@Waccoon]

Sweet. My dad worked for GTE and used the 65SC150 as an embedded core in his designs. Testing SOC cores was a problem since they didn't have stuff like JTAG and on-die debug back then. He came up with the idea of using multiple mask test probes to check each part of a chip independently, as it wasn't practical to make a single probe for each flavor of SOC they made. The 6502 core was tested first and then they tested all the other parts of the chip before they sawed the wafers apart.

[@8bittimes]

In fact the Set Overflow pin was used by the Commodore floppy disk drives. The hardware was shifting in and out bit-serial data from the r/w head and was using the SO pin to signal the CPU when a new byte was ready. That made a 3-cycle wait loop possible, so very quick response times and low jitter. If an IO address would have to be read in every loop, this would be an additional 4 cycyles. I found this use of SO very ingenious.

[@vcfederation]

Commodore did a lot of ingenious things. One of them was putting a microchip into the drive to make it more intelligent.

[@Ometecuhtli]

This channel is awesome and this is such an underrated interview with one of the most influential chip designers.

[@vcfederation]

We are very glad that you like our channel. Please like, subscribe and tell your friends about this channel!

[@jimmydansbo7847]

I did not go into this video expecting to be hit in the feels... Absolute last that said is... "I want you to know, this is my life. So, thank you" ...

[@vcfederation]

We are glad that you enjoyed the talk. He is a great speaker and loves to contribute back to the hobbyist community. We appreciated that he freely gave his time to give a talk at our shows!

[@MartinGalway]

The Super Nintendo also used Bill's 65C816. Lots of games computers relied on his work :) I did a lot of work on the BBC Micro and C64.

[@vcfederation]

Lots of great accomplishments for this man beyond the 6502!

[@MrApaHotel]

This is gold 👍👍🙂🙂

[@vcfederation]

Absolutely!

[@MartinGalway]

I was hoping someone would ask him a question I have wondered about for a long time... where did the "Rockwell Mnemonic Set" come from? Instead of LDA #$05 you would say LDAIM $05. More typing in some cases, less typing in others, but I believe the assembly time would be shorter as it's sort of pre-assembled in the mnemonics - handy for a 1MHz development system! Anyone know?