The Sinclair QL Forum

Hm, interesting, still not sure if I wanted one or not. Maybe yes, probably depends on the price. In any case, I think it makes sense to upgrade the CPU, 1MB is very limiting. But more than 4MB doesn't make much sense either at the original QL speed. More RAM makes QDOS slower. The effect is so not...

In principle I would largely agree with Peter on this. One thing which I would change is implementing a 128K shadow RAM and reducing the 8301 RAM to 64k only. If I were limited to one change outside of a straight re-implementation of the original motherboard (perhaps with some ore modern and compati...

In this case the problem with changing the clock is even worse because it's NOT only due to switching at pre-defined intervals because otherwise one gets illegal pulse lengths on the clock line. The problem is that the whole issue mentioned relies on wrong assumptions. First, the 020 does not do any...

Misunderstanding? Why would a fast serial card have a HDMI connector on it? :) I don't think it's THAT fast :) though the number of channels is correct :) BTW with a master clock at 48MHz, the top baud rate is 3M, this is compatible with the better FTDI serial to USB bridges, which might come in ver...

68008 CPU (HD/MC68008P12) 12Mhz Max. The 68SEC000 is the same price and MUCH faster and cooler. Also, two more address lines than the PLCC version and four more than the DIP-48. I wish Sinclair used the DIP-52 version of the 68008 back then, before the PLCC one was available. As far as I know, ther...

Most signals can be observed on the pins of the DIP chips... That being said: 1) Forget the exact position of the 68008 - nothing serious used that as the original socket was a POS and taller than all the others. 2) Duplicate pins (through-hole pads) for a vertical J1 right behind the original J1, w...

I am thoroughly surprised a 700MHz ARM based SOC sould not read fast enough from GPIO. Someone is not programming it very well... usually bare GPIO (ports) can run at 25+ MHz speed, which is actually enough since once a byte/word is read, the rest of processing works at full speed. I mean, QXL could...

Side observation... I still haven't figured out how the 8301 generates NTSC timings. It has to be configured by the JSU ROm version, because replacing it with a Minerva or plain JS ROM stops NTSC, but I don't know of a register in the 8301 that sets this value. mc_stat equ $18063 status register ad...

I am a bit surprised it's not 10MHz, gives a longer total period, and I think 100ns should be precise enough

By doing this you also change the effective acceleration voltage for the screen, to a HIGHER value, as well as the retrace current, which stresses the HV transformer and rectifier, as well as the damper diode. So... do this at your own risk, knowing that there are no spare old CRT TVs