I had a theoretically working computer by the end of the last entry. It could input and output binary data to and from RAM, ROM, a 65C22, and some LEDs. I was heavily considering a form of video output and keyboard input, and settled on using the Motorola MC6847 for the former, and was undecided about the latter. I decided to think of a list of things I wanted to add onto the computer (from most to least important), and here it is:
Some sort of s
I watched through most of Ben Eater's 6502 computer video series a while back (if you haven't yet I really recommend you go watch them; I really learned a lot). He uses a 65C02, a 65C22, a 62256, 28C256, and aather crude address decoding to make everything tick. I didn't watch all the way through the video series, but I don't think he made the system to be programmable without using the EEPROM and an external system. So, I thought it would be rather cool if I could make what was essentially the
I ordered a bunch(2) bet goodies from Michael Hill at bitfixer.com; a PETdisk MAX and a ROMulator. The former is a floppy drive emulator that plugs into the PET's IEEE-488 port, the latter is a RAM/ROM replacement daughterboard that plugs in between the motherboard and the 6502.
When I got my PET 4016-N, I immediately knew I had to upgrade my RAM to 32k and have some form of disk drive. The thing is, Commodore punched holes through where the 8 extra 4116 SRAM chips would go on the mo
The Compaq Portable II is a really weird computer. I've found a few blog entries and videos that are supposed to explain how this is supposed to work but none seem that helpful. So I decided it'd be nice to make a complete how-to for people that can't figure out how to get their Compaqs working(like me a week ago). All disk images required can be found at the bottom.
Before I begin, a huge thanks to @wierd_w for helping me get the Compaq working and sending me the diskettes nd variou