Tips:
This firmware was written using BASCOM AVR.

Get the demo version (will compile up to 4kB, but we need less than 1kB) from: www.mcselec.com

The AVRs program can be flashed from BASCOM-AVRs build in programmer (use STK200 stetting).

Before plugging the FLASHED TOS x4 PCB into the ST load the HEX file into the AVR.

Do not insert the flash EEPROMS (AM 29F040B) into their sockets while programming the AVR.

Connect the needed wires (MISO, MOSI, SCK, RESET, +5V at TP3 and GND at TP6) from the AVR programmer
to the Flashed Tos x4 PCB.

Connect the AVRs supply (+5V at TP3 and GND at TP6) via the marked solder points on the PCB.

You may get the +5V from a regulated power supply or an USB-Port.


This is very important:

First load the AVR-HEX-File into the AVR.
Next set the AVRs fuse bits besides the fusebit HIgh3 (External Reset disable).
Check everything twice.
The last step is to set the HIgh3 fusebit (External Reset disable).
From this point an error will be displayed because the serial (ISP) programmer
can not longer make a connection to the AVR.
The reset line is needed by the AVR programmer but also to connect the button.
If something went wrong you need to desolder the AVR and can flash it only
with a high voltage programmer.


This hardware was sucessfully tested with an ATARI 1040ST.
It was designed to work with a 260ST/520ST/MEGA ST, too.
There are two PCBs to archieve biggest flexibility.


Popsel 2008-06-19

FLASH X4 12.HEX
FLASH x4 12.bas
both files, as a zip archive