Bygonebytes

Electron Clone v2


I have been considering for some time some changes (improvements!) to add more features and to reduce the chip count. The chip count is roughly the same as a BBC Master!

Here are some of the changes I've been thinking about:

Add:

A joystick Port - possibly not?
Just after playing with an SD card adapter - MMFS/2
Include the MRB directly on the PCB
USB power ports directly on the PCB

Remove:

The UHF modulator
The Cassette interface
Remove composite video port
Remove the audio port (I added)
Remove the Printer Port?
Expansion connector.

I need more PCB edge real estate for connectors but I also want to reduce the overall size of the PCB.

To shrink the PCB size I could reduce the number of IC's - I could replace approximately twelve 74 series with three PAL IC's. Nine less..

And to add to the mix a new ULA replacement has been announced on Stardot. To prototype these changes I am building a Clone v1.2 board to try out some of these changes particularly the fitting of the ULA and the IC reduction ideas before committing to a new PCB.


Looking out the major parts to start building the test board and also looking at chip reduction.



Starting to solder in the resistors and then the IC sockets.



Creating the 68 pin socket from single in line socket strip using off cuts to ensure all pins align.



Adding in the oscillators and the RGB socket.



and the power connector, the keyboard socket and sound stage.



I'll add a few more capacitors then I'll stop here until the new ULA is available so I can check the height of links etc. anything that may end up under the ULA daughter board.

In the mean time I'll take a look at making a small plugable PCB with a PAL IC to replace the first group of four IC's - IC's 13,15,17, and 18. It will also reduce the number of decoupling capacitors. I may be able to remove all these IC's anyway if I remove the composite video and UHF outputs.