First I would like to thank Andre Bertram, who sent me information about ATMEL FLASH ROMS and allowed me to use some code fragments for programming the device, which he had developed for his Atari OS ROM replacement (AFLOS).
PLease vist his homepage at

The software part

First you have to save the contents of your old ROM to disk.
CPBB.COM will do that for you and create 15 different files called BBPGXX.BIN.
These will take 64 kb of memory on your disk, so please use a new one to save the files.

After doing the hardware part, the file FLASHBB.COM will rewrite the contents of the files back to the FLASH.
Make sure, that both jumpers are set.

Both programs you should start from floppy disk only, cause during the FLASH process you will not have access to the harddisks. 

The hardware part

What you will need ?

1 single sided striped prototyping board
1 32 pin DIL socket (high quality one)
2 14x1 adaptor (which fits into socket on one side and prototyping board on the other)
2 Resistors 10k Ohm
2 2x LST connectors
2 adress jumpers
2 74 HCT 139
1 ATMEL 29C010A

some inches of wire


We will build an adaptor for the FLASH-ROM, that fits into the old ROM socket
The 74 HCT 139 will be piggied back on another chip 

- setup the the adaptor board as shown in the picture
- blue lines could be soldered directly between the DIL socket and the adaptor, red ones must be created with some wire
- attention, the adaptor must be soldered in from soldering side of the board

- then take one of the new 139
- bend up every pin, that has a red connection or no connection
- set this chip on the second 139 you bought
- solder the connections between the two 139

- locate the 74 XX 139 near the 74 XX 640 on your BB
- pull this one out and replace it with the two chips you have soldered together

- locate the ROM and replace with the adaptor socket you had created
- wire the last four connections
- the line "to 6821" should be wired to PIN 12 of the 6821 (this one was used already, if you own a Floppy-Board)
- the line "to 74175" should be wired to PIN 14 (formerly used was PIN 15, we need PIN 14, no mistake)

- with jumper J1 you can select between 2 ROM versions (f.e. original ROM, modified ROM)
- with jumper J2 you can set FLASH mode on (J2 set) or off (J2 not set), you should only set J2, when you want to update the BB Firmware