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That is a good question. There are many digital models now. So you will get a lot of recommendations. If you are starting out though...

I did some experimentation with this recently; added a 2K option ROM (the smallest BIOSes will actually handle sanely) that just mapped...

The one ROM expansion I remembered didn't replace the CBASIC but instead uses the spare ROM socket...

For when I have a 5160/5170 motherboard, with only video card, out on the table, I made what is pictured at [here]. Via large alligator...

I added all the remaining scanned documents and disk images to archive.org. It's a bit messy, but I'll go back in and edit the...

My first IT job out of college was working in a hospital. One of the things I had to do often was interface labratory equipement via...

Yes, the circuit diagram and BIOS source code refers to it as 'Port B'. U127 used for outputs. (Port B write.) U128 used for inputs...

I just home & checked tracking its shows that the delivery was changed to tomorrow. So I'll talk to you tomorrow Scott B.

The NMI is enabled/disabled by the XD7 (bit 7 on the external data bus) and 'NMI CS' coming into U118.

Complicating the matter, with the background RAM refresh mechanism either faulty or disabled, the cells in a row of a RAM chip still get...

The Pi1541 is a PCB that connects to a Raspberry Pi3 (multiple versions) via the expansion header. Instead of running an operating...

I have just come into custody of some alpha stations and have no idea how to get them booting :) will be fun to figure it out I supoose

Is the 'Checking interrupt IRQ0' test in Ruud's Diagnostic ROM (RDR) version 3.9 still failing ? I ended up comparing the source code...

I did some experimentation with this recently; added a 2K option ROM (the smallest BIOSes will actually handle sanely) that just mapped...

Thank you @GloriousCow and everyone who help me in this thread. I realized I download ibmlogo.ans incorrectly and got the right one.