Z88 PCB Extender Card


Picture of the PCB

Have you ever thought of designing some hardware for the Z88?

Here is the 'dream' card that enables you to do just that.

It has five key functions which can be used separately.
  1. Use the Z88 as an EPROM Programmer
  2. Use an external EPROM programmer to Program a Z88 card  (EPROMs or Flash)
  3. Use to connect to Test a prototype board externally.
  4. Use the extender to Test a Z88 card externally from the Z88
  5. Use an ICE (in-circuit emulator) to see what the Z88 signals are doing in real time.

Main description

The Z88 Extender card which has the gold edge connector for the Z88, is supplied as a 'bare board,' all other components to be ordered separately. It has the space to fit

When the Extender card is used with a Z88, the 'Card Flap' needs to be modified, to allow the PCB to go through the flap.

Why was it built?

Some developers have expressed the need of developing hardware like external cards to read the new flash chips, or different communication devices using a modern approach. The high cost of getting an external card made has put some users off from taking this further. It is hoped that this card will enable those people to take thier ideas further, by using this card as a stepping stome to the finished article. 

EPROM Programmer

ZIF socket fitted to cardFitting the plastic card case and a zero-insertion socket allows the Z88 to program chips up to 512K (like the Flash chip (AM29F040B)) with ROMcombiner, or ROMupdate. This could be used to program the 512K Flash chip that can be used instead of the ROM in slot 0 of the Z88.

Up to 1M chips may be programmed by using an additional adapter card that fits into the DIL socket and using the additional signal A19, which is on a pad.

If this socket is used, the 2 x 34 way connectors cannot be fitted.

Program a Z88 card

Z88 extender card with EPROM programmerUsing a 32 way DIL and 8 way SIL header plugs, this card can be used with an external EPROM programmer (like the Dual Powered Willem Universal EPROM Programmer+27C256) or the W-USB programmer 1.5 EPROM programmer to program Z88 EPROMs or Flash cards up to 1M.

This allows developers designing software with the Emulator, to 'build' the image there and then download the file to the EPROM programmer to use on the Z88, saving time and complexity of saving the file first to the Z88 and then blowing the Flash or EPROM there.

Full instructions on how to use the card with this programmer is given.







Test a protoype board

The 2 x 34 way connectors used are the same ones used for the older type of IDE connectors to the hard disks. These connectors take all the signals from the Z88's bus to an external board where building and testing can take place. Plug in or transition connectors may be used depending on personal requirements.

Test a Z88 Card

Normally, it is impossible to test an external card when this card is in the Z88. By cutting another plastic card cover, to expose the PCB and leaving the connector end intact, probes may be used to see what is going on in real time. 

Use an ICE

As all the connections are paralleled out of the Z88, an "In Circuit Emulator" can be connected to the card with the DIL and SIL connector (like the NEW external W-USB programmer 1.5 EPROM programmer) or by using the 34 way cable connector.

The Vcc 5v supply from the Z88 to the ICE should be disconnected. This can be acheived by breaking the connection in the connecting ribbon  cable.

Components required

As this card can be used for different purposes, not all the components are required, nor can one card be built to use all the functions. Non-standard components are available from us, or faulty Z88 motherboards and memory cards may be canabilised to extract the Z88 card connectors and memory card cases. The standard components shown here are linked to the Farnell site. If you would prefer us to get these for you, we can and will add a 'handling fee' to cover our costs.

Function required







EPROM Programmer







Programming a Z88 card with an EPROM programmer







Testing a prototype board with the Z88







Testing a Z88 Card







Using an ICE







Components required





Z88 Plastic Card Case
Rakewell
Z88 Modified Card Case
Rakewell


Z88 Modified Card Flap
Rakewell
Z88 Card connector
Rakewell

HEADER, IDC, STRAIGHT, 34WAY x 2
109-6992 



CABLE ASSY, RIBBON 34WAY
101-2214




SOCKET, IC, ZIF, 32WAY
113-6782




HEADER, STRAIGHT, 16WAY x 2
124-8124



HOUSING, 26AWG, 8WAY
109-8717



SMALL BIT OF WIRE or




RIBBON CABLE, IDT, 8WAY131-3461



Circuit Diagram

The circuit diagram of this card can be viewed by clicking here (which will open in a new window).

Using the Z88 Extender Card with an EPROM Programmer

Although I am showing this card being used with the Willem Universal EPROM Programmer, these techniques and instructions may be used with other models.
assembled card for EPROM programmerSolder the required components onto the card.

For 1M cards

A small piece of wire or ribbon cable is used to connect the A19 signal to the programmer to the 8-way header on the Programmer. There are two pins that are marked, the 2nd pin from either end. If you are using a different programmer, find out where the A19 pin is and connect the wire to that point.

For 512K cards

The 34 way connectors are shown fitted. They are used with a  shorting plug (with pins 1 - 18 connected) to pull up A19 to Vpp when programing the 512K Flash cards.

Use an existing Flash card to read the data and then verify it. Make sure that all your soldered joints are good ones as bad ones will produce errors when testing the card as well as testing your patience.  If you get any data errors, check all your connections and soldered joints.

Setting it up

There are two parts of a chip -
  • physical
  • and electrical.
The Z88 Extender card is being used as a physical adapter between the 29F040 - 512K Flash chip and the 1M Z88 Memory card.
  • The 29F040 is a 32 pin DIL device that would normally be programmed in the 32 pin ZIF socket. To set up the EPROM programmer to use this card, you need use the configuration settings given to use this physical device. On the Willem Universal EPROM Programmer, this is set by switches and jumpers, but the method of selecting this may be different on other programmers.

    As this is a 512K device with no spare pins left, we need the additional A19 signal taken to the card to allow 1M addressing that is required for the Z88 Memory card. This is why the A19 wire needs to be collected separately, it is not on the ZIF socket.

    Using both the ZIF and A19 pins gives us all the physical connections required irrespective of what chip is inside the Z88 Memory card.
  • Now that the physical side is taken care of, we turn our attention to the electrical side of things - i.e. what do we do with those signals? By selecting the device inside the Z88 Memory card, the programmer will know what to do with the signals. Do we care what physical package that device is at this stage? No, as we have selected the Z88 Memory card using the physical package in the previous section. This means you must IGNORE any information given on the physical information of the chip under test.
To correctly configure and connect the EPROM Programmer to be use with this card, the power should be turned off.

The Z88 Extender card is connected first with either
  • the A19 lead or
  • the shorting connector 
but NOT BOTH.

Then the switches are set to configure the layout of the 32 pin ZIF socket.
Here are the settings for the Willem Universal EPROM Programmer,
Z88 extender card with EPROM programmerThe Z88 Extender card is now plugged into the programmer's ZIF socket.

The Z88 Memory card is used just to get the correct spacing of the two cards but is removed before power is applied to the programmer.

Choosing the Device

There are 3 devices that are used with the Flash Card. These are:-


They are set up as follows

Am29F080 1M Flash


With no Z88 Memory card plugged into the Z88 Extender card
  • Connect the A19 lead
  • Connect power to the EPROM programmer 
  • Connect to the PC and
  • Initialise the EPROM Programmer
Select the chip you wish to use. In this example we are using the Am29F080 1M Flash TSOP chip.

Now plug in the Z88 Memory Card.
So here is the screen on the chip.

Do we take any notice of the switch settings for the physical settings given for the TSOP40B/PSOP44?      No       Just use the commands like
  • Chip type
  • Read Data
  • Verify Data

AM29F040B - 512K Flash

 With no Z88 Memory card plugged into the Z88 Extender card
  • Connect the shorting connector
  • Connect power to the EPROM programmer 
  • Connect to the PC and
  • Initialise the EPROM Programmer
Select the chip you wish to use. In this example we are using the Am29F040 512K Flash chip.

Now plug in the Z88 Memory Card.

AM29F040B - 512K Flash

 With no Z88 Memory card plugged into the Z88 Extender card
  • Connect the shorting connector
  • Connect power to the EPROM programmer 
  • Connect to the PC and
  • Initialise the EPROM Programmer
Select the chip you wish to use. In this example we are using the AMIC A29040 512K Flash chip.

Now plug in the Z88 Memory Card.

Here is the view of the AMIC 512K Flash chip.

REMEMBER TO IGNORE THOSE SWITCH SETTINGS
Other devices may be selected, like RAM, EPROM and the INTEL Flash chip, but REMEMBER TO IGNORE THE PHYSICAL DETAILS given for ANY devices you are using with this card.

Availability Only a few cards are being manufactured, so if you are interested, please let us know to discuss pricing and other such matters.