Computers That Don't Do Windows

These pages are dedicated to older computers that existed prior to the great homogenizing of the computer industry by the IBM PC and its compatibles.

A really cool computer, the PDP-5 from Digital Equipment Corporation.

The Digital Equipment Corporation VAX Architecture

I've got a lot of VAXes, no I don't know why, I just do ok? I've started writing stuff up about them in a section I call "Chuck's House of VAX." (Sound's like a Vincent Price movie doesn't it.)

The SIMPLEX Educational Computer

I've been working on an easy to understand computer architecture that would be easily implementable in an FPGA. The name for this architecture is SIMPLEX and my plan is to use it in teaching/explaining the basics of computation to kids before the school tries to brainwash them into believing that all computers run Excel and they never make mistakes.


The VAX uses a disk controller called the RQDX3 (M7555) to control MFM hard disks, an a dual floppy drive. To format the RD54 drives you need the latest firmware images.

These files 340E5.HEX and 339E5.HEX are sufficient. (alternate rqdx3.tgz) I don't know if they are the latest, but I do know they work. They are in Intel HEX format. Save them to disk then burn them to a couple of 27128A EPROMs.

Note that if you are looking at the board with the fingers (where you insert it) on the bottom, then the 340E5 chip is on top and the 339E5 chip is on bottom.