The Sinclair QL Forum

Hello friends!

I was lucky enough to pick-up an Aurora and backplane a few months ago and intended to replace my hacked Iss5 QL board in a PC case with the Aurora plus SGC.

Before I re-model the PC case (which also has a PC mobo plus a QXL fitted simultaneously) to accept the Aurora+SGC, I wanted to test the board in isolation from a separate 2A 5v PSU.

Question:

Is such a 5v-only test configuration 'safe' for the Aurora, given that it's serial driver ICs won't get their +/-12v supply?

I appreciate that the power config jumpers first need to be set to accept 5v from the backplane ..

Also, whilst I have downloaded the beautifully detailed Aurora manual, I'd love to get my hands on any schematics. Does such a document exist publicly?

Thanks in advance!

Hi Martyn,

Nasta published the Aurora schematic A4 GIF file, MACH PLD MACHXL source code on the now defunct YooHoo QL Hardware Groups. Ican not finc this anywhere.

However, I have taken a copy of the files. I am not sure if these files are okay to be published here or on the QL HomrPage, maybe Nasta can give permission.

I was also given the Aurora PCB files in an old CAD format, which I managed to load into Altium Designer.

I have been naming all the PCB tracks, and drawing up a schematic in Altium Designer. The Aurora PCB files maybe able to make working Gerber fikes, but the MACH PLDs are very scarce.

I have trying to understand MACHXL code, to convert to a verilog based FPGA. But as Nasta has said, it maybe hard to do.

The Aurora needs +12v, -12v for serial ports, there mighf be other places those voltages are required.

I used to build Auroras into a PC Case, with a QPlane or MPlane, both needed 12V for the PC Power supply. The QL needed the Voltage Regulator bypassed, which does cause problems.

The Aurora Mplane, SuperGold Card can just squeeze into a cube case, but using an AT or ATX case is maybe the bext way to go.

Thank you, Derek!

From my own experience - you can power up the Aurora with 5v only - it will not be able to transmit RS232 without those voltages - but they are not used for the logic chips and basic operation.

There is a mod that can use a different serial level shifter (ADM208EAR) with onboard +/- generation. With that mod the board can be 5V only with working serial. The existing 1488/1489 are as used on the original QL and do need the +/-12V generated off-chip.

Thank you gentlemen!

I'll complete my testing later this evening and let you know how I get on