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-
- A Logic Probe for the Experimenter.
- -----------------------------------
-
- Important:-
- -----------
-
- This was designed to work on a standard A1200 only. It does work on an
- A500(+) but it is slow when using only 512Kb of memory. Although it also
- works on an A600, a standard 9 pin ~D~ type socket will NOT fit into the
- ~Games Port~ so some modifications to such a socket WILL be required
- before you can attach it to the computer. I have NO idea whether it will
- work on an A1000, perhaps someone can let me know via EMAIL. It also
- WILL run under Workbench 1.3x to Workbench 3.1x. But has only been
- thoroughly tested on Workbench 3.0x, (that is a standard A1200). I also
- have NO idea whether it will run under Workbench 1.2x or less or OS3.5x
- or greater.
-
- ----------------------------------------------------------------------------
-
- Further Information:-
- ---------------------
-
- This device is purely for experimentation only. It uses the ~Games Port~
- of the AMIGA as an Analogue to Digital Converter. It is NON linear but
- that does NOT matter as the software allows for it. Only ~POTY~ is used at
- the moment but ~POTX~ would give another A-D Converter if needed. It has
- had limited testing but HAS been ~Multitasked~ with the ~TestCard
- Generator~ from ~TestGear1.lha~ (Project1), the ~Function Generator~ of
- ~TestGear2.lha~ (Project5) and the ~Audio Wattmeter~ of ~TestGear2.lha~
- (Project7), on an A1200, all in real time, (similarly on an A600 with 2MB
- of memory, but it was slow). The calibration is very simple indeed.
- It does NOT need any cells or batteries to calibrate. Just use the simple
- calibration software provided in this drawer.
-
- ============================================================================
-
- Technical Specifications:-
- --------------------------
-
- Maximum Input Voltage....... 12 Volts positive only.
- Over Voltage Protection..... 10 Seconds.
- Input Impedance............. Greater than 10 KilOhms.
- Detectable Pulse Width...... Approximately 10mS.
- TTL/DTL Logic 0............. 0 Volts to 1.2 Volts, + or - 0.2 Volts.
- TTL/DTL Logic 1............. 3.5 Volts to 5 Volts, + or - 0.2 Volts.
- CMOS Logic Detection........ Yes but limited.
- Indeterminate DC Voltage.... 1.2 Volt to 3.5 Volts, + or - 0.2 Volts.
- Display..................... Large Coloured Lights. Green=Logic 0,
- Red=Logic 1 and Yellow=Indeterminate.
- Negative Logic Detection.... No.
- Settling Time............... Approximately 2 seconds.
-
- ----------------------------------------------------------------------------
-
- Parts List:-
- ------------
-
- 1) R1............. 150 KilOhms, 1/8 Watt.
- 2) R2............. 560 Ohms, 1/8 Watt.
- 3) R3............. 15 KilOhms, 1/8 Watt.
- 4) R4............. 560 KilOhms, 1/8 Watt.
- 5) R5............. 12 KilOhms, 1/8 Watt.
- 6) VR1............ 1 MegOhm preset variable.
- 7) VR2............ 4.7 KilOhms preset variable.
- 8) Q1............. Any small signal silicon NPN transistor, (BC107).
- 9) D1,D2.......... Any small signal silicon diode, (1N4148).
- 10) Veroboard or any type of Stripboard.
- 11) RCA/PHONO socket.
- 12) 9 Pin ~D~ type socket to fit the ~Games Port~.
- 13) ~D~ type cover to suit.
- 14) Small box, hardware, sleeving etc..
-
- Notes:-
- -------
-
- 1) All items can be sourced from any supplier.
- 2) All tolerances + or - 10% or better.
-
- ----------------------------------------------------------------------------
-
- General Information:-
- ---------------------
-
- The construction of the ~Cable~ is exactly the same as for ~Project9~.
-
- There is NO board layout for the ~Circuit~ as this is an experimental
- device only. You should be able to build this unit from the ~Circuit~
- diagram by now and cut any strip board as required. If you are unsure
- about the construction of the circuit board, do NOT continue, wait until
- you have gained a little more experience and try again later.
-
- ----------------------------------------------------------------------------
-
- Calibration of the A-D Converter:-
- ----------------------------------
-
- 1) Read the ~Warning~ file and switch OFF the AMIGA.
- 2) Set both preset variable resistors to about HALF resistance.
- 3) Connect test point 2 (TP2) to test point 3 (TP3).
- 4) Plug the unit into the ~Games Port~ and switch ON the AMIGA.
- 5) Start up the ~Calibrate~ software.
- 6) Adjust VR1 to give approximately 250 in the window.
- 7) Disconnect test point 2 (TP2) from test point 3 (TP3).
- 8) Connect test point 2 (TP2) to test point 1 (TP1).
- 9) Adjust VR2 to JUST give 0 in the window.
- 10) Disconnect test point 2 (TP2) from test point 1 (TP1).
- 11) The A-D Converter is now set up and ready for use.
- 12) Switch OFF the AMIGA and disconnect all of the hardware.
-
- Note:- The ~Games Port~ may read ~JOY2~ etc..
-
- ----------------------------------------------------------------------------
-
- Interpreting the display of the ~Probe_Logic~ software:-
- --------------------------------------------------------
-
- 1) Allow 2 seconds settling time per reading.
- 2) Logic 0 will show a constant GREEN.
- 3) Logic 1 will show a constant RED.
- 4) Indeterminate DC will show a constant YELLOW.
- 5) Indeterminate Pulse will show YELLOW for about 1 second followed by a
- short flash of RED or GREEN, doing this approximately once every second.
-
- 6) If you run this software without the ~Games Port~ A-D Converter
- connected only a YELLOW light will show. The system should NOT crash.
-
- ----------------------------------------------------------------------------
-
- *** WARNING ***
- ---------------
-
- DO NOT USE ON VOLTAGES GREATER THAN + or - 12 VOLTS.
-
- Using the experimental Logic Probe:-
- ------------------------------------
-
- 1) Read the ~Warning~ file and switch OFF the AMIGA.
- 2) Connect up the ~Games Port~ A-D Converter.
- 3) Connect the ~Cable~ to the A-D Converter.
- 4) Switch ON the AMIGA.
- 5) Start up the ~Probe_Logic~ software and begin probing.
- 6) When finished switch OFF the AMIGA and disconnect all of the hardware.
-
- ----------------------------------------------------------------------------
-
- Acknowledgements:-
- ------------------
-
- First of all many thanks to my wife Tricia who allows me to spend many hours
- on my computers.
-
- Also to David Benn and Herbert Breuer for the ACE/AIDE combination supplied
- on an AMIGA FORMAT floppy disk which made it easy to compile this program.
-
- ----------------------------------------------------------------------------
-
- Mr Barry Walker,
- 70 King George Road,
- Loughborough,
- Leicestershire,
- LE11 2PA,
- England.
-
- Email to:-
-
- 106161.3245@compuserve.com
- or
- wisecracker@tesco.net
-
- BYE.....
-
- ----------------------------------------------------------------------------
-