STBlitter Rev.A
Blitter & IDE expansion for Atari 520ST(M)
With optional 256KB ROM decoder

Download schematics and Gerbers:
Please make sure to carefully read the included readme.txt before building this board!

IDE Interface and ROM decoding is based on schematics from P.Putnik:


Blitter expansion fitted, with a CF adapter directly plugged into the board. The IDE interface is not buffered so you need to use very short or no cables.


Blitter is working:


IDE speed at close to maximum for an 8Mhz ST, when aided by the Blitter in Hog mode.


The board is made with through-hole component so should be quite easy to build for the DIY’er.
Biggest obstacles are desoldering the CPU from the Atari motherboard, and programming the 16V8 PLD.DSC_2971


Rev.A has some extra bits for testing which ended up not being necessary.

These are the schematics without the unnecessary resistor R8 and solder-jumpers SJ1 & SJ2.