F2R16-A01 - Flash based ROM Replacement for Amiga Computers

Submitted by GG on Thu, 06/15/2017 - 02:49
Project Status

A new version of this project is available here

F2R16The Amiga, like many other computers of the late 80s, uses 16-bit wide mask ROMs to store the machine firmware. Unfortunately, the pinout of these ROMs is incompatible with the JEDEC defined EPROM pinout. Memory manufacturers produced "ROM compatible" EPROMS like the 27C400 to allow development and quick turn manufacturing. These EPROMS are however becoming quite hard to find and still require a UV lamp to erase the chips. F2R16 brings all the benefits of modern flash memory technology to any platform designed to use these obsolete devices.

The design is heavily based on the older F2R16-A00. The major difference is the added support for older Amiga motherboards (A2000 V4.2 and A500 V5). The schematics is pretty straight forward. It uses a 2-8Mbit TSOP-I flash device of the 29Fxxx series and adapts it to the 27Cxxx pinout. WE# and RST# which do not exist in the 27Cxxx pinout are wired to a header to allow programming on a TL866 using the F2R16-PROG adapter.
When using a 29F800 flash ROM, A18 can be used to select the active 512KB bank (useful for dual kickstart configurations).
The support for older motherboards is enabled by cutting the bridges at the R4 and R7 positions and mounting R6 and R5. The modification must be reverted to program the device unless the adapter is also modified.

Support for older Amiga motherboards

To support older revision Amiga motherboards (like A500 V5 and A2000 V4.2) it is necessary to add R5 and R6 and cut the trace shorting R4 and R7.
The resulting configuration can no longer be flashed unless the modification is reversed.

Programming the F2R16

The adapter requires a programmer that can support the 29Fxxx series of flash devices. A simple adapter can be hand wired for programmers with a 48-pin socket.
When using the popular TL866 programmer, it must be equipped with both the TSOP-48 adapter and the F2R16-PROG adapter. A jumper wire is also required to connect WE#, RST# between the adapter and the F2R16. The A18 signal must also be connected when using 29F800 devices.
The vendor and chip in the TL866 software should be set to the actual chip soldered on the F2R16.


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