The bottom-left hand corner is where the disc and speech interfaces live. In this picture we can see the Intel 8271 floppy disc controller and related chips, as well as the two Texas Instruments speech chips.

Although this machine has the speech interface fitted, the speech upgrade is not complete as the serial ROM system is not fitted. This consisted of a socket fitted to the left of the keyboard which could take "serial ROMs", a couple of extra capacitors added to the keyboard PCB, and a 10-way ribbon cable connecting the ROM socket to the main PCB via the connector just below the speech chips.

The idea of the serial ROM system was to allow additional speech phrase ROMs to be added, as well as games and utilities on ROM without taking the Beeb to bits. Unfortunately, the idea never caught on and no phrase ROMs apart from the standard "Kenneth Kendall" ROM were issued, or any other utility ROMs.

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