Below I present my another project which was developed during past year in my free time.
What is this?
This is a 4 bank x 512KB Kickstart ROM based on popular 29F160 memory chip which is able to store up to 4 different standard 512KB Kickstart ROM images and switch them on user request without any jumpers, switches or drilling holes in the casing. This Kickstart ROM will work with Amiga 500 rev.6 and rev.8 boards (it wont work with earlier revisions because of Amiga OOPS bug). It will also work with Amiga 600 but it may be harder to find a proper reset output without soldering.
How this work?
A small ATtiny AVR microcontroller is used to select the current memory bank. You need to connect the reset sense line to Amiga reset. Now how it works: if you press the Amiga reset combination (CTRL+Amiga+Amiga) for a short time, computer will reset normally and nothing else happens. If you press reset for around 500ms, you will hear a beep from a small buzzer located on memory PCB, and bank 0 will be selected. If you keep pressing reset for another 2 seconds, you will hear 2 beeps and bank 1 will be selected. Another 2 seconds, 3 beeps for bank 2, and further 2 seconds, 4 beeps for bank 3.
After releasing the reset line, your Amiga will boot into Kickstart version located in selected bank. That way you can switch between different Kickstart images and/or Diagrom by simply pressing the reset combination. Selected bank number is saved in ATtiny memory and is preserved even if Amiga is unpowered.
How to program it?
I made a small USB programmer with ZIF (zero-insertion-force) socket for programming of these memories. Programmer is controlled by my application working under Windows operating system (see screenshots). Programmer appears in Windows system as a HID device so there are no drivers necessary.
These memory modules should also be able to be programmed using popular programmers as they are based on 29F160 memory chips and control pins (A18, A19, WE, BUSY) are accessible on goldpins, but I didn't do any further tests.
How to connect it?
These memory modules are meant to be used as a replacement for standard 40-pin Amiga Kickstart ROM memories and they should be connected exactly the same as original memory chips. Reset sense line should be connected to Amiga reset. For Amiga 500 the solution is easy as reset line is accessible on keyboard connector. I made a small adapter with buffered reset output (and also HDD led buffered input and keyboard clk/data for other purposes). For Amiga 600 you will need to find reset line (for my needs I soldered a cable to a reset line located on A600 OpenAmiga600FastRamExpansion expansion by SukkoPera).
Memory read/write speed
On my PC and under Windows 7, memory read/write of one 512KB bank in 16-bit mode is as follows:
- read: 29 seconds,
- write: 78 seconds.
Preprogramming:
Memories are shipped with banks 0, 1, 2 erased and bank 3 programmed with Diagrom by John Hertell.
Now for the pricing:
Memory module 4 bank x 512KB - 25 EUR (27 USD),
Programmer with ZIF socket - 30 EUR (32 USD),
A500 keyboard adapter with buffered reset output - 5 EUR, (5.5 USD)
PC software (updated 28 June 2025):
AmiRomProg v1.04 installer
AmiRomProg v1.04 executable
Shipping worldwide via Polish Post registered shipping is 7 EUR (or 8 USD).
What is this?
This is a 4 bank x 512KB Kickstart ROM based on popular 29F160 memory chip which is able to store up to 4 different standard 512KB Kickstart ROM images and switch them on user request without any jumpers, switches or drilling holes in the casing. This Kickstart ROM will work with Amiga 500 rev.6 and rev.8 boards (it wont work with earlier revisions because of Amiga OOPS bug). It will also work with Amiga 600 but it may be harder to find a proper reset output without soldering.
How this work?
A small ATtiny AVR microcontroller is used to select the current memory bank. You need to connect the reset sense line to Amiga reset. Now how it works: if you press the Amiga reset combination (CTRL+Amiga+Amiga) for a short time, computer will reset normally and nothing else happens. If you press reset for around 500ms, you will hear a beep from a small buzzer located on memory PCB, and bank 0 will be selected. If you keep pressing reset for another 2 seconds, you will hear 2 beeps and bank 1 will be selected. Another 2 seconds, 3 beeps for bank 2, and further 2 seconds, 4 beeps for bank 3.
After releasing the reset line, your Amiga will boot into Kickstart version located in selected bank. That way you can switch between different Kickstart images and/or Diagrom by simply pressing the reset combination. Selected bank number is saved in ATtiny memory and is preserved even if Amiga is unpowered.
How to program it?
I made a small USB programmer with ZIF (zero-insertion-force) socket for programming of these memories. Programmer is controlled by my application working under Windows operating system (see screenshots). Programmer appears in Windows system as a HID device so there are no drivers necessary.
These memory modules should also be able to be programmed using popular programmers as they are based on 29F160 memory chips and control pins (A18, A19, WE, BUSY) are accessible on goldpins, but I didn't do any further tests.
How to connect it?
These memory modules are meant to be used as a replacement for standard 40-pin Amiga Kickstart ROM memories and they should be connected exactly the same as original memory chips. Reset sense line should be connected to Amiga reset. For Amiga 500 the solution is easy as reset line is accessible on keyboard connector. I made a small adapter with buffered reset output (and also HDD led buffered input and keyboard clk/data for other purposes). For Amiga 600 you will need to find reset line (for my needs I soldered a cable to a reset line located on A600 OpenAmiga600FastRamExpansion expansion by SukkoPera).
Memory read/write speed
On my PC and under Windows 7, memory read/write of one 512KB bank in 16-bit mode is as follows:
- read: 29 seconds,
- write: 78 seconds.
Preprogramming:
Memories are shipped with banks 0, 1, 2 erased and bank 3 programmed with Diagrom by John Hertell.
Now for the pricing:
Memory module 4 bank x 512KB - 25 EUR (27 USD),
Programmer with ZIF socket - 30 EUR (32 USD),
A500 keyboard adapter with buffered reset output - 5 EUR, (5.5 USD)
PC software (updated 28 June 2025):
AmiRomProg v1.04 installer
AmiRomProg v1.04 executable
Shipping worldwide via Polish Post registered shipping is 7 EUR (or 8 USD).
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