Denial

That's a good idea. But I'd also like to know what the test is doing in relation to the port.

Thank you!

Joe

I'm having a strange issue with a VIC-20 CR. The issue is that it fails the diagnostics test for the datasette port. The odd thing is that the datasette can read and write to and from different cassettes without any issues. I tested the diagnostics components on a different VIC-20 CR I have, and eve...

No problem in asking because that is always possible. But I do always check to ensure everything is connected properly with the TOP labels facing up before powering on. I did check the continuity all the way to the diagnostic cassette connector, and it's fine. I even checked the continuity on the co...

I actually think that both you and I are chasing a ghost with regards to the diagnostics. You're trying to find out why the diagnostics is failing on the CHAR ROM even though the computer boots up and works properly. On the VIC I'm working on, it also boots and works fine. It's just that the diagnos...

Ran out of time today. Was working on more travel plans.

Hopefully tomorrow.

Joe

I've never had a problem where multiple copies of a bin file on an EPROM causes a problem. Not on the VIC, C64, C128, C16, or C Plus/4.

That is very strange!

Joe

Close enough for me.

Joe

It's a CR. I have two diagnostics cartridges, and both do the same. Maybe it's CR version related? I don't think I have another CR, but I'll check tomorrow. It's dinner and cold beer time for me.

Thank you!

Joe

I'm interested to hear what you discover. I have the same PCB's, but my diagnostics card is direct from a vendor. Are you in the U.S.? If so, you could send me the chip in question and I can test it in several of my VIC-20's for you. And I'll pay return postage as well. If you're in Southern Califor...

That was an interesting question as to whether the harness was needed for ROM testing. So I ran the diagnostics without the harness, and the ROM tests occur before it checks the ports (the first port checked is the serial port). For the ROM tests, you should get the following (source: http://blog.ty...

Yes, it does. To be honest, I didn't expect it to work.

I loaded a program from a tape, ran the program, inserted a blank tape, saved the program, cleared memory, loaded the program from the new tape, and ran the program. No issues.

So what does that mean?

Thank you!

Joe

I recently acquired a VIC 20 in an unknown status. After cleaning and visual inspection, I powered up the system and it boots fine. I then powered off, inserted the diagnostic cartridge and the harness components, and ran the diagnostics. The result was "Cassette Port - Bad". I checked the...

Thank you for all of the replies! I greatly appreciate it! It is a strange motivation to learn assembly, but it ignited the fire just the same. To be specific, I have a copy of some VIC 20 Diagnostic firmware that has a bug when it comes to determining how to display on the screen (I get odd colors)...

I'm new to assembly language, and I would like to learn it for the VIC-20. I have some source code that I would like to examine to see if I can find a bug(s) that is present (I didn't write the code). Before I can do that, I need to learn assembly for the VIC-20, and I need a recommendation on a goo...

Here's where I purchased mine for my VIC 20's and C64's that I have. I could tell the difference immediately from my regular composite cables I was using.

https://www.ebay.com/itm/165784501517?h ... Swa5RgAQOO

Joe