This is the back of the Acorn ROM cartridge, with space for two 28-pin ROMs or EPROMs, with the notch facing downwards.

I do not rate the Acorn ROM cartridges because I have had a lot of problems with them. The greatest difficulty they present is that they are much smaller than the Care Electronics ones so the ROMs go down partly into the ROM hole and rest flush with the computer casing. If a ROM is not pushed down into the socket as far as it will go then it is impossible to get the ROM cartridge plugged in. If you want to use an unusual ROM then you cannot use an Acorn cartridge.

Because the ROMs rest against the cartridge flap on the Master, removal and insertion of cartridges has the effect of scraping off the labels on the ROMs. You can see this in the picture above where part of the label from the right-hand ROM has scraped off. Apart from being an irritant this can be dangerous because the loose bits of sticky label have a habit of falling down into the ROM socket and causing the cartridges to malfunction. Either the ROM sockets will not be recognised at all or you will be lulled into a false sense of security only to find that the Master decides to crash for no apparent reason with a screen display that looks like a badly received page from Teletext when the bit of label gets in the way.

The edge of the Acorn cartridges follows the exact shape of the moulding around the computer's ROM cartridge socket. This means that they must be inserted with a degree of accuracy only available to those with an Electron microscope. Sometimes it is impossible because the ROMs catch on the springed flap on the way down preventing a smooth insertion. After seven or eight attempts you realise it would be easier to load the ROM image into sideways RAM.

The plastic casing around the ROM sockets on the Acorn cartridge is very soft. Every time you use a screwdriver to ease out a ROM, a new dent appears in the casing; this again is visible in the picture. At the top end of the cartridge, the space between the ROM socket and casing is so small that using a screwdriver is impossible so you have to do all the levering from the other end and risk bent and broken pins.