CLEAR SPEECH FROM CURRAH MODULE
THE CURRAH U Speech module is a black plastic box which plugs into the back of a Spectrum and gives an amazing range of facilities. The unit is approximately 3in. square and 0.5in. high. Once plugged into the Spectrum expansion port, no more expansion is possible unless a motherboard is used, as it lies flat behind the Spectrum.
There are two leads from the unit. One goes into the aerial socket and the other into the MIC socket. The lead to the TV is plugged into the socket on the back of the unit. That must be done before powering-up the Spectrum.
The unit provides its own copyright message at the top of the screen when powered-up and pressing a key will also start the unit into its keyvoice mode. That is where every key used is spoken by the unit. All the keywords except the tilth (~) are spoken - even the direction arrows which come out as CURSOR. The colours, of course, are not spoken or the various modes.
The keyvoice is controlled by a variable called KEYS and can be turned-off by LET KEYS=0. That can be used directly or in the program and the keyvoice can be turned on again by LET KEYS=1. The keyvoice also works for keys pressed in the INPUT or INKEY$ unless disabled.
Another useful feature is that S$ has been allocated as a speech buffer and any LET S$ command makes S$ into a spoken string. Only letters are allowed, which is a pity, since numbers would be useful. Letters can also be used in brackets to give single or double allophones. An allophone is a sound rather than a letter in speech and words be programmed to must sound correct.
Most words will be satisfactory if typed-in directly but Os, As and some others may need a set of allophones instead. In that respect the booklet with the unit is very good, giving clear examples and a list of suitable alternatives. Unfortunately the variable KEYS does not effect the speaking of S$.
For the technically-minded, the unit contains a ULA which works on a WRITE command from the microprocessor, a ROM containing the keyword speech patterns and SP0256-AL2 speech processor. It also contains a clock for clear speech and an audio modulator to transfer the sound to the TV lead. The sound can be adjusted by using a screwdriver on the screw showing on the top at right-hand side of the box.
The U-Speech allocates itself the top 256 bytes of memory at switch-on and moves down the USR graphics and RAMTOP. More can be allocated to that buffer by the use of CLEAR. That makes it incompatible with some programs which use that space for machine code. Details of the buffer are given at the back of the book for machine code users.
Time must be allowed in all programs for the speech as it is updated only by the keyboard interrupt routine every 50ms. That also means that during SAVE/LOAD/VERIFY/BEEP and dealings with any device connected to interface one - i.e., Microdrive, RS232 or network - no speech should be in progress. That is because the speech will continue as one sound until the operation is finished.
The unit is extremely useful but time has not permitted it to be tested with any other units to see if they clash. What is presented is a very good clear speech box, with a very easy way of programming it and, even more useful, a spoken response to any key input. That might become a more than essential unit for some of disabled users.
The Currah U Speech unit costs £29.95. Currah Computer Components is at Greythorp Industrial Estate, Hartlepool, Cleveland TS25 2DF. The company is intending to make it usable for the ZX-81, BBC and other computers.