Signalure an mis on Imp Hewlett-Packard has announced a signature analyser (the 5006A) that offers full option programmability on the Hewlett-Packard interface loop (HP-IL).

Composite signature and signature memory are included and, according to the company, can save the user time when troubleshooting digital circuits by hand. Composite signature sums indivldual node signatures and time is saved in verifying the correct operation of an IC, but or other convenient block of nodes by making one com- parison of the composite signature to the document.

A good composite signature verifies that all individual nodes checked are good. A bad composite signature indicates that one or more of the individual slgnatures is bad.

Time is also saved and operator errors are reduced when gathering or comparing signatures using the new signature memory stack. This eliminates holding the probe on the node, reading the display and compar- ing it to the documentation for each measurement.

All the signatures can be entered on an IC, for example, by simply pressing the probe button when moving from pin to pin. Later, the signatures can be recalled to the display by pressing the probe button in the recall mode.

All the pins on a device can then be probed without reference to the docu- mentation. Only if the composite signature does not match, does the user need to review the individual signatures to find the faulty pins.

Each time the probe button is pushed, a signature is entered into the memory and added to the composite signature. If a new signature is written over an old one by pressing the probe button, the composite signature is updated in the edit mode. Signatures can be reviewed by simply pressing the recall button and rolling the stack with the probe button

In addition to HP-IL programma- bility, the new signature memory and new composite signature function, the HP 5006A offers a number of advan- tages over the original HP 5004A

Speaking of voice synthesizers... The Personal Speech System speech synthesizer from Detroit company, Votrax, has been released in the UK.

The unit receives text and trans- lates it into speech using an onboard, Z80-based, algorithm. Accuracy, for English words, is 95%, according to UK distributors Cyber Robotics. The text can come from a keyboard or a computer with an 'almost unlimited' vocabulary. This is a built-in speaker.

Difficult-to-understand 'robotic' speech found in some systems using a text-to-speech algorithm has been improved, claims Cyber. The Personal Speech System incorporates a pro- grammable inflection and amplitude. Music synthesis is possible with pro- grammable attack, decay, sustain and release times.

There are 350 programmable fre- quencies for sound effects and speech in 64 levels of amplitude. Serial and parallel interfaces are included as

Votrax pronounces 164 as 'one hundred sixty four'

standard. A clock can be programmed with vocal alarm signals.

There is a user defined exception word table, expandable ROM, down- Ioadable software, a 3500 character input buffer [subdiwsible for a printer buffer), oral power up and error prompting, Xon, Xoff and RTS-CTS handshaking and baud rates program- mable from 75 to 9600. (Cyber Robotics Ltd, 61 Ditton Walk, Cambridge CB5 8QD, UK. Tel: (0223) 210675. Telex: 817672 VESCOL G)

• the 25 MHz clock rate extends the signature-measurement capability to higher-performance digital circults

• CMOS logic thresholds, In addltion to standard TTL, offer a more thorough coverage of dlgltal products

• displays and unstable light can detect intermittent faults and unstable signatures

• HP-IB programmability is available as an option allowing the additlon of the slgnature-measurement function to automatic test systems

• two modes of the signature measure- ment (normal and quality) for simplified component-level fault- isolation are compatlble with the HP 5005A/B signature-multlmeter products

According to the company, the use of small dedicated test stations is now feasible w~th the interface loop with a concomitant improvement in produc- tivity and saving of time. Instrumenta- tion is now claimed to be feasible in smaller operations where previously it was not cost effective.

Logic-probe status is now avadable at the programmable interface. The HP 5006A can therefore offer greater test coverage with a controller that has more information for guided backtrace algorithms.

For example, the controller can report the difference between a stuck logic-high or logic-low signal and a signal that is always logic-high or loglc- low at clock time. In addition s~mple logic-probe troubleshooting can be automated. The controller can read logm-high, high impedance state, logic- low and active data from the probe through the HP 5006A.

The HP 5006A is completely programmable from the HP-I L or HP-I B interface. With a single special command, the complete front-panel status can be sent to the controller. The controller can do the reverse -- control (reconfigure) the front panel with one command. According to Hewlett-Packard, these features make test procedures faster to generate and run. (Hewlett-Packard Ltd, King Street Lane, Winnersh, Wokingham, Berks RGI I 5AR, UK. Tel: 0734 784744)

240 microprocessors and microsystems