forum.defence-force.org

I'm curious what the reason for the 15th pin is - the Telestrat keyboard looks remarkably similar - perhaps the 15 pin board was a precursor to that to allow extended characters?

I wonder if anyone has tried something like this with an Oric - looks like it has a good chance of working assuming the printer is fairly basic http://lpt2usb.com/

This endeavor sounds a bit trickier than I first imagined, nevertheless I'm determined to plug away until I hit a hard roadblock and have fun trying - On that note, do you know if there is an IC that exists that would allow me to create a 14 way SPDT switch bank (I'm probably not describing that cor...

After taking them apart I noticed that one of my two Atmoses has a 15 pin connector on the keyboard versus the usual 14 pin one - the motherboards of both machines have a 14 pin header so I'm curious on a couple of things: 1. It is safe to assume that the striped wire on the 15 pin connector should ...

I was thinking the use of the DPDT switch along with using diodes on the 14 way y cable I'll have to make would help isolate the Oric from the Teensy. I don't have a working rig yet so what I'm not sure about is if I mechanically isolate the 5v and 0v lines would the 4051 signal pins still have a ch...

Thanks for the feedback so far - the Pi Zero isn't much bigger than the Arduino board used in the OricPi so both should squeeze in alongside the existing motherboard - heat might be a slight concern so I'll keep an eye on that once its up and running. They Pi Zeros seem to run pretty cool and defini...

Hopefully this project is of interest to some folks here - I'm planning on embedding a Raspberry Pi zero within a functioning Oric Atmos with the idea of being able to switch between the two as needed (ideally by using a hardware switch it would either boot the Atmos or the Pi (running Linux) with j...

Godzil has made some great schematics here that may be of interest https://www.986-studio.com/tag/atmos/

If I recall correctly there's a thread on this board that gives a bit of backstory that there was a shortage for a while then a large quantity were found in a warehouse and sold to part resellers which allowed the prices to become more reasonable (I recently bought a spare ULA for around CAD$10 from...

... 6502 and 6522's out .... I hope that's 6502 A (and 6522 A , too?) as a plain 6502 is too slow. The clock may say 1MHz, but it's a lopsided square wave, with the 6502(A) having to complete in about 1.5MHz-worth of time to get out of the way for the ULA to get two bites at memory. Be warned :) Go...

The tech socketed all the chips and changed all major ICs and RAM now the machine is showing the attached pic. Any ideas? Changing RAM with others changes the display colors. Regulator is showing 4.9V at output so going to change that next.

Oh yes. XT1 (12 MHZ) is the main oscillator, from which all other clocks derive. No CPU, no ULA, nothing of any use. XT2 is only needed IF you want a PAL colour output on the UHF modulator. It does have to be exactly 8.8672375 MHz or the colour carrier frequency will be wrong. Edit to add: It is tw...

I agree changing the caps would be beneficial and had ordered them. In the meantime I gave the motherboards to a tech at work and he said he could use his logic analyzer to check for failed components without needing to plug them in (I'm not sure how this is done, it's way above my very basic unders...

On that topic I imported a couple of dead Orics recently to Canada both of which were dead (I'll create a separate thread on these shortly) Oh, Canadia! There do I live as well. ;) If that is not indiscreet, where did you buy them from? I am currently developing solely on emulation (Oricutron on Wi...

+1 that it's bad RAM chip (160Ohms between GND and +5V is low). Else everything helpful is already said. From the picture we can conclude that 12MHz generator (XT1+IC21) and ULA are working. When the logic probe arrives you can check the presence of F2 signal and event what happens on the address/d...