Wednesday, September 11, 2013

6800 Info from the Woz per Lionel Theunissen's Rig up and running the 6800

Woz's comments on Lionel Theunissen's A-1 rig running the 6800 cpu --

"I designed the computer for the 6800. The Apple I board even has an area for a dozen parts labelled "for 6800"…it also had to have these parts for the 6501, which was a barely cheaper version of the 6502. What these parts did was supply a faster harder clock signal to the chip. Otherwise, the pinouts of the 6800 and 6052 were compatible.

I could buy a 6800 for $40 as an HP employee. That's why I designed the computer for it. Then the 6502 got introduced for $25 ($20 for the 6501). I switched because it was better (in my judgment, with more addressing modes) and cheaper.

The Apple I ran on a 256-byte program, burned into 2 PROMs. We didn't have much memory density back then for these programmable chips. All you'd have have to do is to read my program (given away publicly) with the comments, and translate it to 6800 code. Tight, but doable.

The cassette board, for using a cassette tape drive to store programs, had a 256-byte program of its own on the board. In this case it was in one chip, as I recall. That too would have to be converted to 6800 language for a more complete project.

The next step would be to find some public domain 6800 BASIC and convert it to run in the memory addresses of this computer.

All-in-all, not too hard. But it's a special project worthy of commendation."

ʞɐıuzoʍ ǝʌǝʇs 

Tuesday, September 10, 2013

Another white ceramic 6502 and an 6820

Wow!  you can get both the 6502 and 6802s AMI for just $2500.00 USD (Again, amazingly enough, free shipping [economy])

6502 = 1975 Date Code
6820 = 1976 Date Code

Pretty cool (but I have to wonder if they are still functional)

6502 CPU white ceramic (1976 Date Code)

Ebay   Only 1250.00 USD  (Or best offer, and who can beat "Free Shipping!!!!")

And yet another (1977 Date code) White Ceramic 6502

Just 999.00 USD !!!!

Friday, September 6, 2013