Introduction

EPROM cards are becoming useless as they do not offer much storage.

Benny Boogaert has modified several 32K EPROM cards to 512K Flash cards.

Components used

Component	Manufacturer Part No	Order Code	Price	Min Qty
AMIC - A29040C-55F - MEMORY, CMOS, 4MBIT, DIP-32	A29040C-55F	Farnell	2.76	1
0,2 or 0,25mm Kynar wire
Bison polyurethane professional
Pattex Ethylcyanoacrylaat

This is what he did.

Modification to card

Instructions

Pull off the lid

round off the 4 plastic pins

cut some space around the pins

Drill 2 holes - 0.3 mm each
Strip the wire long enough to
- push it from the bottom to the top,
- bend it back
- push it in the hole and then
- into the copper strip.
Make it as flat as possible, applying a tiny bit of solder.

This is a very strong connection, which does not damage the copper track on the motherboard.

Connect the wires to the chip
and edge connector,
Only use a small amount of solder, leaving
as much of the gold connector as possible.
Make space for the little wires,
not too much as the plastic has
to push the PCB leading wires
around the holes.

Edge Connector	Wire	Chip	Signal
37	Green	1	A18
36	Yellow	30	A17
22	Blue	31	WE#
hole under pin 30	Blank	32	VCC
2	Black	3	A15
1	White	2	A16
Existing connection		16	0v

Flatten the 32 pins and clean up copper.
They go through the pcb too far preventing
the cover to sit tight in it's place.

2 pieces of sellotape were used to keep the
top and bottom of the case tight to start with

one layer up front and one in back,
Tape should be tight and flat

Unfortunately, the tape loosened, causing bad contacts.

Solution - the following steps were taken

Glue the assembly with a small drop of polyurethane on

the 4 plastic points (original holding points)
the 2 sides that slip around the PCB connector
of the Z88 slot with fast glue. Then
let it dry under some weight for several hours.

The card worked super after that.

For the 4 black pins Bison polyurethane professional was used.
It has the tendency to expand (swell up).
Only a tiny droplet was used applied using a tooth-stick.
The case was kept under pressure of 1- 5kg/cm2 for 4 hours.
That made sure that it remained in the correct position.

For the side flaps, a quick glue, official name is ethylcyaanoacrylaat is recommended.

Patex was used but there are a dozen other brands.

This glue sticks within a few seconds and has to be applied at the last instance before pressing the plastic box together.

Here is the flash card being used for files.

Conclusion

Benny Boogaert has shown that it is relatively easy to build your own 512K Flash card for very little money. The difficult bit is getting the extra wires to connect to the gold connector without contaminating it with solder. Not an easy task.

Z88 Leaflets, Applications & Projects

32K EPROM to 512K Flash Card

Introduction

Components used

Modification to card

Conclusion

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