Since many do not dare to use SMD, but there are many who would like to build such an interface, I have developed the ZX1541 interface again in a pure THT version.
And I have to admit, it was not easy to get along with the small footprint. The goal was to be able to build this board into an old memory expansion case from Sinclair.
And it succeeded then nevertheless.
It gets tight
I had to do a little trickery, otherwise all the components would not have fit in this cramped space. Therefore, I have taken the RAM component not the usually used in 15.24mm dimension, but in 7.62mm.
Fortunately, these are still relatively easy to get today. But this alone was not enough. I had to put the RAM chip under the EPROM.
To do this, however, the RAM chip must be soldered, without IC socket.
And with the socket for the EPROM either the bars must be removed, or one takes directly appropriate 14pin female connectors.
So that this is better visible, I have made here once a 3D representation of this construction:
As you can see, this example is shown with two female headers. But also a 28pin IC socket is no problem, as long as you carefully remove the bars BEFORE SOLDERING(!!!). Trying to do this after soldering in often ends up with the socket breaking and thus having to be desoldered again.
I recommend to cut the socket first, then to put the EPROM into the two halves of the socket and then to solder it in. This way the EPROM will fit in later without any problems.
Apart from that, the board doesn’t have any other surprises in store.
Schematic, parts list, the Gerberfiles and also everything else necessary I have made available for download on my GitHub account: https://github.com/DL2DW/ZX1541-Interface_in_THT