Monday, April 21, 2008
My brand new (manufactured just 30 years ago) HP5036A microprocessor lab arrived in the mail today. I'm not sure if you can still get machines like this, but it's quite interesting. It runs on an Intel 8085 @ 2MHz, has 1k of SRAM and 2k of ROM. I've already written my first program, a single instruction that writes the contents of the A register to the ouptut LEDs. To change the A register, you can use the monitor (kind of like a debugger) and then run the program again.
Computers these days are hidden behind so many layers of abstraction it's difficult to really play with them at a low level. The address and data busses are clearly marked on the board, you have full access to every peice of hardware and there's no operating system or memory manager to get in the way. Of course there's no communications built in (except for an expansion port) so you have to enter the bytecode by hand. But even for a huge program, that's only 3,000 keystrokes to fill the 1k of RAM.
I know I'll have a lot of fun with this toy as soon as I start digging into the included textbook.
at 11:12 PM