I found this sight looking for an unwire-wrap tool: http://www.elexp.com/

Found one for $9.95. Minimum order is $20. I tried to order two. Not quite $20 but I tried anyway. Didn't work, so I decided to order 1, and look for something else I need like 74AC14's. They didn't have them, BUT I was very surprised to see they had a 6500/6800 IC section: http://www.elexp.com/ics-indx.htm

I'm gonna say it again, "Holy Crap"!.... They are selling 6845's! for <$3!: http://www.elexp.com/ics_6402.htm

I was looking for this IC months ago...

I ordered some before posting this

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65Org16:https://github.com/ElEctric-EyE/verilog-6502

I got the confirmation email. They say they will charge when shipped, which is normal, but I am highly suspect. I was told this IC was long ago left to rot in the dust... I would've started the video portion of my project with this IC if I'd known I could still get it. I've done 1024 horizontal, with 256 greyscale, using the C64, for a science fair project... So I'll post what I find, when I find it. heh, I'm curious what the production dates are...

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65Org16:https://github.com/ElEctric-EyE/verilog-6502

Sometimes you'll find a few here and there, and if you think there's any chance you'll ever want one or two, it's not a bad idea to have them on hand. But I think it's just a 2MHz part for lo-res video, isn't it? and for monitors with composite video input (ie, not anything like VGA)? It doesn't seem like you'd have any use for it on your fuel injector pulse width analyzer.

I've used it before together with an SMC8002 video attributes generator. I think I had the 8002 up to close to 20MHz. The 6845 doesn't need to do the video clock. It was the perfect interface between the CPU and video adressing. The 8002 VA generator handled the higher speed as I remember on a project I did a long time ago...

Screw CRT's. I'd be interested in interfacing the 6845 composite signal to an HDMI or RGB flat panel display that's 26" plus.

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65Org16:https://github.com/ElEctric-EyE/verilog-6502

What I mean is that you won't be able to put it on your 6MHz or 12MHz 6502 bus.

One place which may have some in stock, shoot an email to www.Eldoradogames.com. I will vouch for this company as I have been working fopr them for 2 decades now. they would be pulls from videogames, socketed ones though. Worth a shot.

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"My biggest dream in life? Building black plywood Habitrails"

Sure you can! Just wait-state the hell out of it. Of course, the system will slow to a crawl each time you need to scribble on the screen, but does that matter? Just how fast can the average person read?

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

It's not about how fast a person can read, but how fast the screen updates while scrolling or full-display redraw. A 1MHz 6845 while rendering text will be just on the edge of acceptability (as indicated by scrolling performance of a Commodore 64 or PET). If you're planning on rendering graphical screens, which most of EE's previous posts seem to indicate, then you're looking at visible tear on the screen.

The IBM XT and PC used a 6845 for the MDA and CGA adapters, and its screen updates are infuriatingly slow. And by infuriatingly slow, I mean slow enough for visible tear to be seen propegating from the top (or bottom) of the screen to the other edge during a single update.

No I won't. I just had a flashback, sorry. The PWA has to be portable. Carrying an old CRT with a composite input would not be feasible or safe. However, if I were to build in a simple waveform capture into the PWA project (a simpe O-scope), it would be nice to see the details on a larger screen once I got back home with the data.



Jeez, that sorta makes me worried. I was hoping these IC's would be unused. If they are used, I would hope they would be tested. Thanks for the link... BTW the debit still has not posted a full day later...



If I were to use a 6845 again, I would use a dedicated slow 65C02 to control and display the video RAM and a faster CPU to directly access the video Ram... There are guys here that have done this already using Phase 2, I've read some of their posts before, but I'm not ready for it YET.

This would be a whole new project, but I was excited to see the IC for sale, so I scooped some up. It's sorta of dismaying that I could be buying used parts, not only that but I won't be able to test them until I put them in use....

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65Org16:https://github.com/ElEctric-EyE/verilog-6502

Just in case you're unable to find a 6845, you should be able to make a CRTC using a microcontroller. If the microcontroller is fast enough, you can even get it to generate memory addresses for you. Alternatively, if you're planning on using a completely different CPU to drive the video circuitry anyway, you might want to use the CPU itself to generate the video refresh addresses.

Just throwing out ideas.

Geesh! Lighten up! "I make yoke!" as Yakov Smirnoff used to say.

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

At significant risk of misunderstanding again, . . .

Lighten up? I don't recall being angry at the time.

And, no, when it comes to electronic communication, I have little sense of humor. Humor depends as much on body language as anything else, and I am incapable of detecting most implicit jokes in written text.

Sorry.

In Soviet Russia, yoke makes YOU!!!

When Smirnoff first came to the USA, his English...er...left something to be desired. Apparently he had difficulty with differentiating the J sound from the Y sound. My sister, who went to school for a year in Moscow and is fluent in Russian, once said that "Yoke" vs "Joke" was quite common amongst Russians learning English. Similar problems exist with certain consonants in other languages (viz, R vs. L for some Orientals learning English).

Smirnoff was very funny guy, and often drew upon life in the former Soviet Union for his material. One of my favorites was: "In the USA, you have the American Express card: don't leave home without it! In the USSR, we have the Communist party card: don't leave home!"

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Yeah, like maybe 14MHz+ to generate the addresses under software control?... I wish I had enough experience in basic video design... I'm gonna do some more research.

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65Org16:https://github.com/ElEctric-EyE/verilog-6502