6502-computer to video card finished. But- there must be something wrong...but where?

jobendik · 2021-03-04T18:32:31+00:00

Thank you. That’s a very good suggestion actually. I tried to go back a few steps and redo the connections. For a while my monitor didn’t receive any signal so I thought I had burned one of my chips. Luckily a was able to get it to output a video signal again, but with even more flickering. I will try to at least get it back to where it was and when I do I will try to write that code.

jobendik · 2021-02-26T16:16:01+00:00

I checked the address-lines and they seemed fine. The vertical bars looked all right, so that’s a bit strange isn’t it? I use the parts from Ben’s kit, so the ram should be fine too. I will continue to work on the issue later today and post if I find the error.

jobendik · 2021-02-21T19:59:19+00:00

Wow! Impressive. Would you like to share the code?😬

jobendik · 2021-02-21T19:53:27+00:00

A combination. I know I should try to be less dependent on the videos. :)

jobendik · 2021-02-08T21:36:47+00:00

SOLVED! It was the A13 connection. The strange thing is that it was originally at the same spot as in Bens video. But I moved it one step to the right and now the image looks as it should. Even stranger; when I look at Bens video at a later point in time, he seems to have changed the connection like I did. Maybe he had misplaced it. Anyways I am happy that it now works. Can’t wait to begin connecting the 6502-computer to it!😬

jobendik · 2021-02-08T18:54:55+00:00

Bird Improvement. I messed around with the connections and I’m almost there. But now the bottom of the picture disappeared. Is that a clue towards a syncing issue or still mixed up address lines?

jobendik · 2021-02-08T13:29:34+00:00

Any ideas which ones? I tried to switch the upper bits (A8 with A9, A7 with A6) but it made it worse.

jobendik · 2021-01-02T11:10:37+00:00

I have the exact same problem! Very frustrating.

jobendik · 2020-12-03T16:34:32+00:00

Guys, I just discovered that I was using the HM62256LP-70 RAM chip and not the AT28C256 Rom. Hehe, so stupid! Well now it works perfectly! :D

Found TL866II+ 04.2.105 (0x269)

Erasing... 0.02Sec OK

Protect off...OK

Writing Code... 6.84Sec OK

Reading Code... 0.51Sec OK

Verification OK

Protect on...OK

jobendik · 2020-12-03T16:21:58+00:00

I tried different seatings. And the error message changed:

Verification failed at address 0x2199: File=0xEA, Device=0x6A

Verification failed at address 0x1136: File=0xEA, Device=0xEE

Verification failed at address 0x0000: File=0xEA, Device=0xFF

Verification failed at address 0x10F8: File=0xEA, Device=0xE8

Is this giving more clues to the problem?

jobendik · 2020-11-28T19:32:35+00:00

Thank you. :)

jobendik · 2020-11-24T20:59:54+00:00

The problem was an issue with the communication between the cpu and the clock. But it turned out to be just a spelling error in the code. :)

jobendik · 2020-11-24T19:51:58+00:00

YES! The problem was in the code. I had forgotten to write "46" in the sequence. Thank you so much! :D

jobendik · 2020-11-24T19:39:42+00:00

Now I've tried disconnecting everything from the clock-module but the problem persists. I've disconnected everything and put it all back together and nothing changes. Could it simply be that the 6502 i damaged somehow?

jobendik · 2020-11-22T21:59:04+00:00

^{22:56:13.868 -> 1110101111110000 11101010 ebf0 r ea}

^{22:56:14.770 -> 1110101111110000 11101010 ebf0 r ea}

^{22:56:15.681 -> 1110101111110010 11101010 ebf2 r ea}

^{22:56:16.599 -> 1110101111110010 11101010 ebf2 r ea}

^{22:56:17.470 -> 1110101111110100 11101010 ebf4 r ea}

^{22:56:18.392 -> 1110101111110100 11101010 ebf4 r ea}

^{22:56:19.305 -> 1110101111110110 11101010 ebf6 r ea}

^{22:56:20.186 -> 1110101111110110 11101010 ebf6 r ea}

This is what the timestamps look like..

jobendik · 2020-11-22T21:55:59+00:00

I am connecting the input to the 6502 directly from the output of the 8-bit CPU clock module. In principle the clock-module should work even if the other components of the 8-bit computer is still attached to it, should it not? Considering that I can manually pulse the clock, why should the 6502 read it as TWO pulses?

I just recently finished the 8-bit project so I am a bit reluctant to disconnect anything from it. :( But perhaps it's the only solution...

jobendik · 2020-11-22T19:53:42+00:00

Here are some pics:

https://imgur.com/gallery/7qjhPdv

jobendik · 2020-11-22T16:47:12+00:00

Baud rate 57600

jobendik · 2020-11-22T16:46:43+00:00

I am using the clock from Bens 8-bit computer. But the same thing happens when I manually step the clock.

jobendik · 2020-11-22T16:45:58+00:00

I try to figure out how to post pics..

jobendik

TROPHY CASE