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You're right. But I would never think to look at that if you didn't tell me (I have not enough knowledge for that, unfortunately... but I'm learning LOL) However the adapter works fine now, and also the printer seems to be OK, I was able to print 6 pages of self test and it didn't stop anymore...

Do you mean I should connect the socket pin #21 (instead of pin #20) to the 74LS04 pin #9, and leave the /CS1 not connected ? I used /CS1 because the original 2732 -> 2332 adapter for the PET machines by Ray Carslen connected /CS1 to /CE. So I just drop an inverter in the middle.

Yes, in example the 2732->2332 character generator adapters for C=64 and VIC-20 are different from the 2732->2332 PET adapter (iirc the adapter for the VIC-20 is also different from the C=64 one). So now I'm quite confused, because I don't know how to make a 2732->2332 adapter for the printer...

the strange part is that even when the printer starts working (i.e. self test) it hangs after about one page and half. I searched through the reset line and it seems to me it's done using a capacitor. The reset line it's also connected to the 555 pin#4 (reset). I think that it costs nothing to...

Well, the reset is high, so we can assume the reset line is ok, am I right? (I'm doubting of everything LOL) One of the first tests I did (I talked about in a previous message) was to check the CPU address lines, and I discovered they were stuck high. So I remove the ROM and test the address...

none of them. I just discovered my board is different, the 555 pin #3 goes to the pin #13 of a 74LS09 (there aren't any 74LS09 in the two different schematics). I need to remove the board to understand better, however if we're expecting an HIGH at the reset line, this is not the issue. I'm...

Dave, based on the schematics from Zimmers (https://www.zimmers.net/anonftp/pub/cbm/schematics/printers/cbm3022_pcb2.gif), it seems to me the 555 is the reset circuit...? :unsure: EDIT: - Strange, there are two pages, one mentioning a 555 as you told, the other mentioning the 555 as reset...

Resume of the day.... I took the example of the 2764 -> 2364 adapter I did for the 8250 FDD and I adapted the idea for this adapter. Then I take the Ray Carlsen's schematics for the 2732->2332 adapter (in the past I made some PCBs based on it) as starting point. I cut the CE <--> CS1 signal...

OK it *seems* I've found the culprit: with the ROM inserted, all the address signals are stuck to high. Removing the ROM, they come back. So I tried to use the same adapter I use in the PET for the 2732 EPROMs in place of the ROMs... and of course it doesn't work ("nothing is easy", feat...

Thank you Colin! I didn't know that. Those manuals will be quite useful, I guess!

well, I opened it removing the mechanical assy (it's like to tearing apart a tank LOL), and I cleaned all the connectors. Then I removed the 4 socketed chip (the big ones are labelled C010750-03 but according with the PCB label should be 6532, then there's the 6504 CPU [I absolutely need to buy...

Thanks for the manual, I just had a PDF and Google didn't do a good job translating it.

great, Dave, thank you. I've already planned to do that. Will tell you asap!

...The interesting part is that today, after a night sleeping, it worked again for a while. I switched it on and it did the normal reset. So I tried to run the self-test, and it did it correctly... for a while. Then it stopped to print (no head noise), no tractor feed, just the head moving left...

Hi all, I own this printer that was tested last time in 2021 and labelled as "working ok" by me. Now I was trying to make some prints but I'm having some issues. I switched it on and I pressed the FEED button a few times while I was trying to understand how to load the paper: it seemed to...

Thank you Hugo; I will open it and put the scope. It will take a while, but I should be able to record the scope signal too. BTW: I didn't know it was possible; I "knew" that when the caps are faulty, they must to be replaced. But, considering the current behavior, it makes sense. This is...

Absolutely amazing! I'm wondering if the original developers didn't even imagine that after ~45 years some smart guys would bypass the hardware limits of these machines and give them some graphic capabilities by software...

Finally I got a clip about the problem. Sorry for the dark image, it's not easy to record it; I'm using the monitor attached to a VCR, just to make things not too boring LOL Hope it can give you some clue about the problem. It seems that the problem happen only when the monitor is "cold"...

Hugo, thanks again. I didn't make a video with the issue yet, I hope I will find sometime this week. The monitor isn't cooperating with that, it's working for hours without any issue, now. I'm sure it will become to show the problem soon or later; I'm just waiting for that moment...

Well done! Proof of patience... something that only married people have LOL