The Sinclair QL Forum

Have a look at the few posts at the bottom of page 1 and also posts on page 2 in this thread: https://www.qlforum.co.uk/viewtopic.php?f=3&t=1143

Pity they did not extend the key design to the keys in the space bar row (including space bar). And it's *&!!@ expensive

IIRC the Minerva sources are now openly available, if the I2C code is present within, it could be used to figure out what addresses the GAL decoded. My guess would be the very last byte(s), but more detail is needed. Two inputs and two outputs are needed for bit-bang I2C, and since the ROM is read o...

Unlikely a zener problem, although that protection method will not hurt. It should be checked if the VGA box has termination resistors on the input RGB lines, these are usually a low 75 or 150 ohms, which the ZX8301 cannot drive (almost a short circuit) and will eventually fail. The RGB output on th...

7805 needs 8V DC at the input with less than 0.3V ripple to properly regulate. The 15.6VAC line certainly does NOT need 2A, rather 0.2A. It's only used to power the RF modulator and the serial port drivers. The simplest way to get a replacement PSU is to buy a 9V SMPS module, 2-3A would be ideal. Th...

Hi Nasta, Do you have any unpopulated PCBs? If not, I was thinking about making more Aurora boards, do you think there is any interest in more Aurora boards. I had an idea of building the Aurora into a QL case with SuperGold Card, Super Hermes. ... Could the QLSD work in the Aurora ROM socket? Dere...

I'm trying to somewhat systematize the internal workings of the 8302 ULA in another thread. There are a few remaining unknowns, one has to do with the IPC communications, mostly the 'interface interrupt'. Apparently this was not used due to problems with the IPC software, but the Minerva source comm...

You need a picture of the bare board, or populated with parts?

It might be useful to mention that microdrives writes apparently use the/some baud rate generator (a byte is written to the drive by placing it in the transmit register, then the status register is polled until the byte is completely ticked out). This means the transfer rate to the tape must be con...

Thanks for the pointers, Jan - I have updated the post above with added data I found.