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Adapter EPROM 16 Bit from Toomas Toots


I made 16 bit EPROM adapter for Willem EPROM programmer.
In attachment of this mail is schematic diagram of this adapter.
For programming 27C1024 have to use 27C010 mode,
for programming 27C2048 have to use 27C020 mode and 27C4002 have to use 27C040 mode.
Making new version of programming software you could add these programming modes too and also modes for 27C160, 27C400, 27C800, 27C322 and 27C801.

On reading 27C series EPROM, the pin31 of the EPROM chip socket should be logical 1.
(Some manufacturers chips this pin may be in both 1 or 0 but others only in 1)

This add-on adapter is actually made and its working well.
Schematics is in pdf format but available also in Protel format.

Schematic

You wrote my adapter not capable to program chips but only read.
That's not right.
I made it about year ago and using it quite well for both - programming and reading.
Working principle of this adapter is very simple. With A0 i'm switching between lower
and higher byte so if address not changes at first the lower byte being writen and on
changing A0 the higher byte is being writen.

For example: For programming 27C1024 (16x128k) I choose 27C010 (8x256k the result
of size is same as 27C1024) mode and dip switches are in same position as for 27C010 programming.
For programming 27C2048 I use 27C020 mode and for 27C4096 I use 27C040 settings.
On writing lower byte then these 10k resistors are for holding other 8 bits in logical 1 state
and on writing higher byte these are holding again other 8 bits in logical 1.

My solution doesn't need any dramatic change of program.
It can be used with already written sub functions.