4004 ROM Emulator Allows Fast Development On Slow Computers

Developing for extremely old computers is a chore; not only are you limited by assembly or pure machine language, there’s also the issue of burning ROMs to actually run your programs. [Frank Buss] came up with a neat solution to developing for the venerable 4004 CPU – build a ROM emulator using a modern microcontroller.

The build started off with a ZIF socket for the 4004 CPU and a 256 byte 4001 ROM chip emulated on a PIC micro. The CPU looked a little lonely sitting in the ZIF socket all by its lonesome, so [Frank] updated his board to allow a 4002 RAM chip to be plugged in as well.

Because [Frank] chose a 4004 for his entry for this season’s retrochallenge competition, we need to point we’re offering a prize for loading our retro site with this CPU. Yes, it’s most likely impossible but nothing worth doing is easy.

You can check out a video [Frank]’s ROM emulator after the break.

One thought on “4004 ROM Emulator Allows Fast Development On Slow Computers

  1. Man, I’m trying to find a single-chip USB MCU solution to emulate a small (<256 bytes) ROM for bootstrapping a ROMless NES cart. This would be great for homebrew as it effectively could give you access to GB's of storage for say, a video-playing demo (albeit at a horrible resolution and FPS). Totally useless for casual piracy ('repro'ing' as they try to call it) since you'd have to totally change the memory-management code even if you somehow filled the program and character SRAM with a ROM image.

    I was thinking of it more as a way to instantly test your patches with both an emulator and real system. Thanks for the ideas in this article – I'll be sure to try out what looks like it'll help!

Leave a Reply to Joe2 Cancel reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.