Axol Electronics Ltd.

Power On Self Test card

front view2 POST cards have been around for years but no other manufacturer appears to take them seriously with most producing greatly overpriced cards which have, for example, LEDs to indicate power is present, a HEX display to show the POST code itself, a flashing LED to indicate there may be a clock and manual links to set which port address to use. Some of these cards retail for hundreds of pounds and yet provide no more than the very basic functions such a card should give.

The POST card from Axol is a little more sophisticated.

ISA/EISA and PCI compatible.

The Axol POST card has 2 edge connectors to allow it to be used in both ISA/EISA and PCI systems. Most computers have ISA slots but the trend is to move toward PCI only machines. Having both ISA and PCI compatibility in a single card removes the need to buy 2 different cards for the 2 different interfaces and ensures that the Axol POST card does not become obsolete in the near future. The PCI connector has universal keying to allow insertion into all PCI slots.

Full text display.

text1 Other POST cards use individual LEDs or a 7-segment LED display to indicate the test being performed. This display shows the HEX value of the test which the user must look up in a manual or a list of POST code descriptions from the BIOS manufacturer.

Instead, the Axol POST card holds the text corresponding to the POST codes for many of the most popular BIOSes in on board EEPROM. The user simply selects which BIOS is in use on the computer via the keyswitches on the POST card and then plugs the card in. On power up the card then displays a readable, text message on the built in Liquid Crystal Display telling the user which test is being carried out. No more searching for that list of POST codes that you had last month and no more looking through pages of BIOS codes to find out what the cryptic HEX number means. Instead, in most cases, the meaning is immediately obvious.
One point to note here, the display on the Axol POST card is 2 lines x 16 characters. While this is certainly a huge advance over the 2 digit hex display of other cards as it conveys far more information to the user, it is not sufficient to display all of the information that some BIOS manufacturers supply. e.g. MrBIOS V3.4x has the following as POST code 01: "Initialize any Custom KBD controller, disable CPU cache, cold initialize onboard I/O chipset, size & test RAM, size cache.". Clearly this cannot be got onto a 32 character display so some points need to be edited and some omitted entirely. The documentation from the BIOS manufacturers' web sites cannot, therefore, be dispensed with altogether.

Clock frequency measurement.

clock With other POST cards you usually get a single LED to indicate that a clock is present.
The Axol POST card measures the clock frequency for you. Now you KNOW that the clock is running and that it's at the correct speed, e.g. it'll be given as 33.33MHz instead of only having a green LED to tell you there is a clock of some indeterminate speed. The Axol POST card will measure the PCI clock and both ISA clocks (CLK and OSC) and will handle frequencies up to 70MHz with a resolution of 0.01MHz.

Power supply voltage

Other POST cards typically have a single LED to indicate that the +5V line has volts on it. Some use a zener diode in series to indicate the voltage is higher than some predetermined level. But how many volts are present? The Axol POST card will tell you. Not only does it measure the +5V line, the Axol POST card measures ALL relevant power supply lines so when plugged into an ISA slot the +12V, -12V, +5V and -5V are each measured. For a PCI slot the +12V, +5V, +3.3V, +Vio and -12V lines are measured. No more having to get the voltmeter out and poke around precariously inside the computer trying to find the pin with the power on it and then risking shorting the power supply out with the meter probes. All voltages are measured using an on-board precision voltage reference and are displayed with a resolution of 0.1V.

This feature allows the Axol POST card to replace an AT power supply tester or ATX power supply tester to give a far more thorough check of the power supply as it is tested under a real load and all the voltages are measured accurately.

Power supply start up time.

12v A common failure with power supplies is that, when the computer is expanded, the extra load of the new peripherals on the power supply can slow the time that it takes for the voltage to reach its specified level. This can cause the machine to fail to reset on power-on as it is the rate of rise of the supply that triggers the reset. This problem often manifests itself when the machine will fail to start on power-on, but a subsequent press of the reset switch will bring it to life. The POST card from Axol helps here too. Not only the supply voltages, but also the 10% to 90% rise time of each supply line is measured and displayed to the nearest 0.1ms. You now know if your PSU is up to the job even before it starts to fail! In order to measure the power supply rise times, the POST card must be running before the power is turned on. To cope with this the Axol POST card has an on-card rechargeable battery to allow the supplies to be monitored before and during power on.

Power supply monitoring.

5v When soak testing a machine the Axol POST card can be left in place and it will continue to monitor all voltage rails. The minimum and maximum voltage on each line is recorded so if the power supply dips or spikes for any reason (e.g. a faulty PSU or a disruption in the mains supply) then, instead of coming into work the next day to a crashed computer with no indication as to why it crashed, there will be a definite indication that all of the supply rails were good or not.

Fully programmable port address.

While other POST cards still tend to use links or DIP switches to select a small number of possible port addresses for the POST card, the Axol POST card is set up via the on-board push-button switches and display. For ISA/EISA 7 port locations are available (hex addresses 60,80,84,85,90,300,278/378). 278/378 is a single setting that will capture any code sent to either of these LPT ports. For PCI any port location on a 32-bit boundary within the entire 64k of I/O space is available so that future changes to port locations will not leave the Axol POST card obsolete.

Programmable to take newer BIOSes.

The Axol POST card comes with the POST text message for the most common BIOSes stored in the card itself in non-volatile memory to remove the need to look up the code manually. To cover future BIOSes, the Axol POST card can be re-programmed with the latest POST codes by the user using a simple DOS program available from this site. Updates will also appear on this web site so the user can conveniently download the codes for the latest BIOSes into the POST card. Between 7 and 15 full BIOS post code lists can be stored in the card dependant on the number of POST codes used by each BIOS. The software is written for use with MS-DOS3.3 or equivalent or better and will run as a DOS program within Windows 3.1 and Windows 95/98. To update the card simply plug it into a PCI or EISA/ISA slot on a working computer, switch the computer on and boot to DOS then run the software. A choice of BIOSes will be available so the user can always have the most common BIOS POST codes uploaded. The software allows any number of user specified POST code lists to be entered so new or non-standard BIOSes can be handled by the card.

Display visibility.

Some POST cards have a single 2-digit LED display to give the POST code and this can be difficult to read if the motherboard being tested is in still inside the computer. An improvement on this is to use angled displays so the display can be read from the edge of the board. The Axol POST card uses a large LCD so the option of standing on its side to be visible is not available. To get around this problem the Axol POST card has an on board, rechargeable battery, charged from the computer. If the card cannot be seen while performing the test then simply touch one of the keys on the card to halt the current test, switch off the PC and remove the card from the computer. The full range of measurements and POST code are all stored and can be reviewed outside of the machine.

Selectable display options.

osc During a test the user can choose which items to have on the display. e.g. If there is a suspicion over a CLK signal then the Axol POST card can be set to show the CLK signal in real time on the display, along with its minimum and maximum values, to allow close monitoring during the test. All measured signals can be selected for display in this way, voltages, clocks and POST code. All the measured parameters are still recorded during this time and can be reviewed as normal after the test is halted.

Power up/down protection.

The interface logic on the Axol POST card is powered from the +5V supply on the PC bus. The internal logic on the card is powered by the on board battery. If the +5V bus line drops out of spec then the Axol post card detects this and immediately disables the interfaces to ensure that there is no damage to the PC from logic signals on the card driving powered down logic on the bus. Similarly, the interface logic is held disabled at the start of a test until the +5V line is seen to be in spec. The Axol POST card then initialises the interface logic ready to accept POST codes from the bus.

PCI/ISA compliance

The card is not compliant with the ISA and PCI specifications. Compliance requires full interaction with the ISA/PCI bus, controlling of bus cycles, handshaking, requesting resources etc. These aspects of compliance all detract from the test functions that the card is attempting to perform. Any piece of test equipment should cause as little disturbance to the system under test as possible as any disturbance may alter the conditions of the test and give misleading results.
With this in mind, the Axol POST card has been designed to be passive and eavesdrop on the bus rather than interact with it. Therefore, the card will never drive any signal onto the bus. Of course, the inputs on the card follow the relevant timing and loading specifications, in particular the PCI inputs which are required to meet rather unusual specifications.
The Axol POST card is designed to operate with PCI 33MHz, 5V bus. Although not guaranteed, it will almost certainly operate fully on a PCI 33MHz, 3.3V system provided the +5V supply is present and is unlikely to work fully on a 66MHz bus. The only non-functioning part of the card on these systems will be the POST code itself. The power supply voltages and bus clock measurements are not dependant on the bus speed and will operate as normal up to 70MHz.

Reverse polarity protection

The Axol POST card has protection against reverse insertion but it is not recommended to insert the card backwards. Although unlikely, it is still possible that inserting the card backwards could cause damage to either the POST card, the motherboard or both. It is up to the user to ensure that this does not occur. The card is well marked to show the required orientation.

Automatic power off

If the card is unused for 10 minutes (i.e. no switches are pushed for 10 minutes) then it will automatically shut off the power to preserve the batteries. Any configuration will be preserved so when next switched on the card will be in the same state as it was prior to powering down. This also applies to the results of the latest test, they are kept by the card until the user explicitly begins a new test. The power down feature is disabled while performing a test as the soak testing of the power supply voltages may take many hours so powering off would not be appropriate. However, during such a test, the computer will be supplying the power to the POST card so there will be no problems with batteries becoming discharged.

Board construction

The Axol POST card is not the most aesthetic product in the world. It is designed to be functional and cost effective rather than to look good. The board is hand assembled at the time the order is received although we will usually have a small number ready assembled in stock. This is done so as to allow each card to incorporate the latest updates in software and any user specified requirements.

The non-component side of the POST card has the component leads close cropped so as not to produce any sharp points which may cause injury while handling. It then has a transparent, insulating, polycarbonate film backing stuck over the non-component side of the circuit board. This film may not be completely flat and may get some air trapped beneath it but this does not detract from the operation of the POST card. Again, this may not look neat, but it does the job, which in this case is to allow the card to be placed on a workbench without shorting out the on-board batteries or damaging the PCB traces. It also prevents shorting out against adjacent cards inside the PC and it remains within the tight PCI specification for the maximum height allowed on the non-component side of a PCI card.


Technical details.

Interface
Standard ISA and EISA at 7 port addresses (hex addresses 60,80,84,85,90,300,278/378).
PCI 33MHz, 5V at any port on a 4 byte boundary.
All edge connector contacts military grade gold plated for extended durability.
Nickel/Gold alloy contacts give a minimum life of 10,000 insertions.

Supply voltages
0.1V resolution on all supply lines.
Precision resistors used for all critical circuitry.
On board precision voltage reference to guarantee accuracy.
Rise time measurements from 0.1 to 999.0ms.

Memory
64kbyte of EEPROM to store the text of the POST messages.
POST code text for between 7 and 15 BIOSes can be stored on card.
DOS software to allow user updates to the POST messages.
User can decide which BIOSes POST codes are stored on card.

Misc.
Clock measurement to 70MHz.
Crystal reference to guarantee timing accuracy.
4.8V 40mAh Nickel-Metal Hydride rechargeable battery charged from the computer's +12V line.
2 line by 16 character LCD.
5mm Character height.
Software compatible with DOS3.3+, Win3.1, Win9x.
PCB is high quality 1.6mm FR4 fibre glass.
Size: 96mm x 101mm x 16mm thick approx.
Weight 106g (3.75oz.) approx.

What you get.

It is the policy of Axol Electronics Ltd. to give the potential customer all possible information before a purchase so that the customer knows exactly what to expect and is not disappointed in any way with the product.
The POST card comes with a single A4 sheet of basic instructions for use which mainly refers the customer to this web site where, hopefully, all the necessary information can be found.
In order to keep the cost to a bare minimum the product is supplied in very basic packaging, there is no comprehensive manual and no software included in with the product, this can be freely downloaded from this site.
The product comes with a 12 month return to vendor warranty to cover any manufacturing defects.
Any suggestions as to how this information can be improved will be considered.


(c)2000 Axol Electronics Ltd.
Registered in England, company registration no. 3155627.
Registered office 35 Grindon Lane, Sunderland SR3 4EU