Recent content by luismcv

Regarding the tape connector, I've been measuring both AC and DC components at several places of both tape 1 (which doesn't work) and 2 (which works) while their corresponding motor signal should be on. I also measured the VIA and PIA pins when OFF. This is what I got: My guess it's the...

I never remembered to mention that this computer seems to have two patches/fixes, either from the factory or most probably done during its lifetime in that workshop it came from. One is what I guess it's a resistor between pins 9 and 15 of the UA19 4116. Pulling up /CAS? What for? Making sure...

*** Short version *** I replaced the 6545 with the 6845 and it's working now. Today I've adjusted the background brightness and the height of the image. But it's a bit displaced to the bottom-right. I don't think it's possible to adjust its position, is it? I've also tested the datasette...

It's late and I'm tired. Tomorrow I'll do a proper post, but I thought about leaving a preview:

Last night I removed the CPUs of the VIC20 and the CBM, put them on additional sockets to make it easier to insert and remove them again without having to worry too much about their legs and I swapped them. I guess that both CPUs are fine, the CBM's worked in the VIC and the CBM still doesn't...

Thanks a lot Dave. Did you disassemble the ROM yourself? Are all the ROMs (or at least more parts of them) disassembled and available for download somewhere? I tried to search on Google some of the comments and all I could find where your other posts in this forum. I don't think I'll have much...

I just received an UM6845 that I got from ebay and tried to piggyback it. I still don't get any sync signals. I've tried to mount it on top and remove it a few times and as far as I know it's making good contact. I pushed the legs inwards using a flat surface, so they fit quite tight over the...

Well, there is definitely some activity: /CS vs RS (AB0) /CS vs R/W (BR/W) /CS vs E (B02) And some data lines (DB0 and DB3) But I think I'll wait until I receive the logic analyser and can see what data it's receiving. Anyway, as it's looking like I might end having to replace the...

I can count in mine 18 groups of two (one for writing the Address register and one for writing the actual register, I guess). Maybe of the 18 is just a read? I'll find out when I get the logic analyser.

Well, I found some time tonight to measure a few things. But first, I've just realised I made two errors when I said "30 HSYNC. ±1.20V weird signal/ noise?" in my first post. That should've been pin 39 and ±0.12V. So it's just a ±0.12V ripple that, at least tonight, after totally...

Hi. Around 15 years ago I was given an 8032SK, with a keyboard and a 8050 dual disk drive. It was working back then. Or least the computer was; unfortunately I didn't have much time or interest back then and I never got to test the disk drive. One day (after some months stored in a corner of...

Hi, I've acquired an European VIC-20 (rev.D, with c64 style power connector) and a cassette (C2N) that doesn't seem to work. The VIC just says "PRESS PLAY ON TAPE", but none of PLAY, REV, FF, REC do anything. - 9VAC pins of the power supply are working. - Internal 9V fuse is fine...