eater6502 - interactive 6502 trainer computer

Keyboard types into the serial console (BASIC)

Front panel STOP, then EXAMINE / DEPOSIT / SINGLE STEP

Code EEPROM Programmer tab → write / load / burn a program

✎ Editor has focus - click the 3D view to type into the machine

Monitor

A front-panel monitor: examine and change any address in the machine's 64K, exactly like the address/data switches on a real trainer. Reads and writes go straight to the live bus, so this is the same memory the CPU is running from right now.

Address $

Data $

Memory around the current address

Send text to the main monitor

The big screen is memory-mapped video: whatever bytes sit in the character window appear on it. Typing here writes those bytes for you, which is exactly what a program would do.

EEPROM Programmer

Edit 6502 assembly, assemble it, then burn it to the emulated 28C256. This mirrors the real Arduino + 74HC595 programmer on the second board - the running CPU can never write its own ROM, only this out-of-circuit programmer can.

EPROM library

A rack of pre-burned chips. Pick one and fit it to the board — the machine resets and runs from it, exactly as if you'd swapped the physical EPROM in its socket.

Write your own

Load .asm Load ROM .bin

Load / Save

Save a full machine snapshot (ROM + RAM + registers) to a file, or load one back in - just like swapping a cassette or disk on a real trainer computer.

📂 Load Snapshot

Cassette tape

The trainer's tape port. Record captures whatever BASIC program is currently in memory as a .bas text file; Play types one back in, exactly as if you were retyping it, so BASIC stores it the way it would any typed program. Works whether or not BASIC is running — Play simply sends characters to the serial port.

⏵ Play tape

Storage card

A CompactFlash card in the socket at $7000 - the machine's mass storage, on the bus like any other peripheral. From BASIC, type SAVE "NAME" and LOAD "NAME" at the prompt, or flick the SAVE / LOAD switches under the monitor. The card image is kept in this browser, so it survives a reload.

⇧ Insert card image

Altair folder

A real folder on your computer for .bas and .asm files. Pick it once and the machine reads and writes there directly, so your source can live in an editor or a git repo instead of only inside this browser. BASIC programs are converted back to readable text on the way out, using the interpreter's own keyword table.

RAM viewer

First 256 bytes of RAM ($0000-$00FF), refreshed live.