ZX Spectrum 48K Issue 3B: Bill of Material

Table of Contents


This is the Bill of Material for a replica ZX Spectrum 48K Issue 3B. It is optimized for PABB’s ZX Spectrum 48 Issue 3B Redrawn boards.

Read Me First!

If you want to build your own ZX Spectrum, be aware that the machine was designed in the early 1980s.

While almost all of the standard components are still available, some components are rare by now. You will need all of the listed components (except of those marked optional). We recommend that you try to get the components marked as Rare first, so you won’t waste your money on standard components if you fail to get all the rare ones.

This bill of material only comprises of the components required for the mainboard itself. For a complete ZX Spectrum replica, you will need:

If you are new to electronics and soldering, there are easier ways to build your own ZX Spectrum. For example, there are kits for the Harlequin 48K and Harlequin 128K clone that include all components and detailed assembly instructions.

Rare Parts

The easiest way to get these parts is to buy an old or broken ZX Spectrum, and salvage them.


This Bill of Material includes sockets for all chips. All sockets are optional, of course. In an original ZX Spectrum, sockets were used as deemed necessary by Sinclair at that time, but usually the ULA was always socketed, while the lower RAM and the LM1889N were never socketed.

Generally we recommend to use precision sockets. However, if you are going to use replica parts (e.g. a replica ULA or a memory board), you should check if they fit into precision sockets, and maybe resort to standard sockets.

If you are going to use the Retroleum Nebula as ULA replacement, all nearby chips (IC3, IC4, IC24, IC25) should be soldered directly to the board, as they would collide with the Nebula board otherwise.

If you want to heatsink the original ULA, you might have to solder it directly to the board for space reasons.


Four wire jumpers need to be set depending on the components that were used.

The first set of jumpers can be found to the right of the MIC connector. They need to be configured depending on the type of the upper RAM chips.

Again, note that all eight chips must be of the type that is configured by the jumpers. However, you can mix them with any number of 4164 RAMs.

The other set of jumpers can be found next to the speaker. They configure the manufacturer of the ROM chip.


This is not an official list! It was collected and reviewed by Sinclair enthusiasts.

Although we strive to make the information in this project as helpful and accurate as possible, it is provided “as is” and without warranties of any kind either expressed or implied.

In other words: You might spend a lot of money, and end up with a non-functioning board or a cardboard box full of useless components.

Use at your own risk!


This list is meant to be a community work. Our goal is to have a canonical list that people can rely on when ordering parts for building an own ZX Spectrum mainboard.

However, this list may not be free of errors. If you have found one, please open an issue or send a patch.


This project is distributed under the terms of GNU General Public License (GPLv3).