Acorn Electron OSTC Open source Turbo Card

I came acrosee this project some time back but until now didn’t think I was qualified. In the last few months I acquired some extras for my little Elk such as a plus 3 interface and added a gotek. The plus 3 also houses a AP6 interface which is an amazing piece of kit allowing for all maner of interesting configurations. A few repairs and mods later on various machines and I decided to tackle this project.

The PCB is a 4 layer board , shown below, which PCBWay made for me. The service from PCBWay was excellent with the boards arriving very quickly. They are great quality and for a great price. I decided to go with black PCB’s this time as I’ve tried red,blue,green and white with various other projects.


REF Component Part no.

C1, C2, C3 150pF 1206 size ceramic capacitor 399-8157-1-ND (Digikey) Received AliExpress 25/7/2023

C4, C5 22uF 1206 size tantalum capacitor 478-3865-1-ND (Digikey)

VR3v3 3.3v LM1117 voltage regulator LM1117MP-3.3/NOPBCT-ND (Digikey) Received AliExpress 25/7/2023

R1 2Kohm 1206 resistor RMCF1206JT2K00CT-ND (Digikey)

R2 4Kohm 1206 resistor RNCP1206FTD4K02CT-ND (Digikey)

JTAG, SW1, DBG 0.1″ pin headers, right-angle 547-3223 (RS Components)

6502 2x Low profile 40-way turned pin socket 197-2726 (RS Components)

ElkMB 2x 20 way round pin headers (see below) BBL-120-T-E (Toby Electronics)

Xilinx XC9536XL 44-pin CPLD 122-1385-ND (Digikey) XC9500XL XC9536 jed file here

SRAM IS62C256AL-45ULI 706-1043-ND (Digikey)

The photos below were to verify how the board will look before assembly.

And these are the finished board ready for assembly.

I’ve got as far as soldering the XC9536 and the JTAG connector so that I could test programming the chip. The wires are temporary just to supply 3.3v to the board.

However programming the chip has prooved a challenge as the xilinx software refuses to work on my windows machine so I’m researching an alternative method programming the chip.

For any other PCB fabrication including component assembly and for any 3D printing visit