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Feb 10, 2024, Regarding shipping methods: up until now ROM-SIMMs could be shipped by international registered mail, but if EEPROM is considered an electronic device, it may be returned, so shipping by international registered mail is no longer possible. If you specify international registered mail, shipping without EEPROM is limited. Please note.


There are 2 types, select from options




This card is a ROM SIMM with the concept that users can freely program it with our great APP, Crucible!
Cards reverse engineered from Vintage Macs have their ROM chips replaced with PLCC32. The PCB is the 4x PLCC32 type you often see, but this is a redesign, not a clone.


We have prepared 3 colors to match your image. Black, Red and Purple.

It has an LED, but the color is only Blue.


Compatible with: SE/30, IIx, IIcx, IIci, IIfx,IIsi

*Can also be used when ROM hacking on some 040 machines and MacII. Most models require a SIMM socket to be installed.


Can be used by general purpose programmer


If you use TL866II+ or newly released T48 programmer, you can flash the program without using Custom ROM SIMM programmer. There is a post on Tinker Different's forums here with more details. Of course, we also accept questions about the program and flashing.

If you are new to ROM programming, it may be a little hard, but if you program it many times, it will gradually become easier. TL866II+ programmer is so popular that you can find many instructional videos on YouTube.


To make your own ROM


Crucible Apps
Use our apps called "Crucible" for the MacOS, Supports High Sierra to Ventura.
Crucible V1.1 Download here
Tutorial is here.

Drake's amazing narration tutorial video:


1,    Create a Boot Disk (.img) 

2,    Edit Boot disk with MiniVmac

3,    Combine ROM and split the combined .bin into 4 files

4,    Flashing the EEPROM with T48 or TL866II programmer


Optional EEPROM


Please select EEPROM from the options. This is the pre-programmed 2MB ROM(AMD AM29F040B x4pcs) for our SMC ROM SIMM card, but for a deeper dive into the world of Vintage Mac , we encourage you to learn a little bit about ROM technology with a ROM programming do-it-yourself project. It is recommended!


You can use the EEPROM listed bellow:

SST39SF040 (2MB for 4pcs)

AM29F040B (2MB for 4pcs)

SST29SF010 (512KB for 4pcs)

AM29F010B (2MB for 4pcs)


There is a shortage of EEPROMs worldwide, and prices have more than doubled. Best if you can get it locally. 

In addition, when using used EEPROM recycled in China, there are quite a lot of defective products, so be careful.

*New EEPROMs can be purchased from Mouser or DigiKey. 


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