Search found 37 matches
- Tue May 21, 2024 11:45 am
- Forum: Hardware and Tech
- Topic: What can cause the diag to report bad char rom?
- Replies: 13
- Views: 325
Re: What can cause the diag to report bad char rom?
Here's a link to the Commodore 64 Dead Test manual. Page 2-7 explains what I mentioned about a faulty CIA in a C64. http://c64.rulez.org/capac/portal/wp-content/uploads/hardver/dead_test/781220_Manual.pdf As stated, I would "assume" that the test logic is similar in the VIC test. Thus, one...
- Mon May 20, 2024 3:14 pm
- Forum: Hardware and Tech
- Topic: Diagnostic Tools for the Vic-20
- Replies: 22
- Views: 3200
Re: Diagnostic Tools for the Vic-20
I just noticed something on the second screenshot image. The clock is missing from the diagnostics screen. VIC20DIAG.jpg Even a BAD ROM diagnosis should still show the clock on the screen VCDIAG2.jpg On a C64, if the same thing happened during a dead test, the CIA chips were suspect. On the VIC 20, ...
- Fri May 17, 2024 8:45 am
- Forum: Hardware and Tech
- Topic: Diagnostics - Cassette Port Bad
- Replies: 10
- Views: 458
Re: Diagnostics - Cassette Port Bad
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
Thank you!
Joe
- Fri May 17, 2024 8:44 am
- Forum: Hardware and Tech
- Topic: Diagnostic Tools for the Vic-20
- Replies: 22
- Views: 3200
Re: Diagnostic Tools for the Vic-20
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...
- Thu May 16, 2024 2:49 pm
- Forum: Hardware and Tech
- Topic: Diagnostics - Cassette Port Bad
- Replies: 10
- Views: 458
Re: Diagnostics - Cassette Port Bad
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...
- Thu May 16, 2024 2:44 pm
- Forum: Hardware and Tech
- Topic: What can cause the diag to report bad char rom?
- Replies: 13
- Views: 325
Re: What can cause the diag to report bad char rom?
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...
- Wed May 15, 2024 9:41 pm
- Forum: Hardware and Tech
- Topic: Diagnostics - Cassette Port Bad
- Replies: 10
- Views: 458
Re: Diagnostics - Cassette Port Bad
Ran out of time today. Was working on more travel plans.
Hopefully tomorrow.
Joe
Hopefully tomorrow.
Joe
- Wed May 15, 2024 9:37 pm
- Forum: Hardware and Tech
- Topic: What can cause the diag to report bad char rom?
- Replies: 13
- Views: 325
Re: What can cause the diag to report bad char rom?
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
That is very strange!
Joe
- Tue May 14, 2024 6:47 pm
- Forum: Hardware and Tech
- Topic: What can cause the diag to report bad char rom?
- Replies: 13
- Views: 325
Re: What can cause the diag to report bad char rom?
Close enough for me.
Joe
Joe
- Tue May 14, 2024 6:46 pm
- Forum: Hardware and Tech
- Topic: Diagnostics - Cassette Port Bad
- Replies: 10
- Views: 458
Re: Diagnostics - Cassette Port Bad
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
Thank you!
Joe
- Tue May 14, 2024 3:43 pm
- Forum: Hardware and Tech
- Topic: What can cause the diag to report bad char rom?
- Replies: 13
- Views: 325
Re: What can cause the diag to report bad char rom?
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...
- Tue May 14, 2024 2:29 pm
- Forum: Hardware and Tech
- Topic: What can cause the diag to report bad char rom?
- Replies: 13
- Views: 325
Re: What can cause the diag to report bad char rom?
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...
- Tue May 14, 2024 2:02 pm
- Forum: Hardware and Tech
- Topic: Diagnostics - Cassette Port Bad
- Replies: 10
- Views: 458
Re: Diagnostics - Cassette Port Bad
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 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
- Tue May 14, 2024 10:26 am
- Forum: Hardware and Tech
- Topic: Diagnostics - Cassette Port Bad
- Replies: 10
- Views: 458
Diagnostics - Cassette Port Bad
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...
- Wed Feb 07, 2024 3:02 pm
- Forum: Programming
- Topic: Recommendations for VIC-20 assembly tutorial, tools
- Replies: 10
- Views: 2091
Re: Recommendations for VIC-20 assembly tutorial, tools
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)...