SWTPC 6800 Cards

[antiquekid3]

Well, I finally got around to taking pictures. Here are some of the interesting cards that I can find little to no information on (except the MP-LA at the bottom right).

Here's an early sound card (Newtech Computer Systems Model 68 Rev. B):

I think this is a clock. It's a JPC CK-7. It uses an MM5318 chip (rightmost), and considering the MM5316 is a clock chip, I can assume this is too.

Here's the power supply that was included with it (it was plugged in to the board when I got the computer).

This is another JPC board, the TC-3. The info I found on this indicated this is some kind of tape interface...but how in the world can this be so much less complicated than the AC-30?!?!

Any information would be greatly appreciated!!

Kyle

 

[antiquekid3]

I guess these cards must be more uncommon than I thought! If anyone has any information (especially to the sound card!), I'd love to hear it! That's one card I'd like to make operational in the computer.

Kyle

 

[nige the hippy]

Give it some time, and maybe a chip number or two - it's a shame that the site limits the size of picture file - the numbers on most of the chips are unreadable - some nerd somewhere will work out the function of these cards!

 

[JOELAV]

You've got some mystery boards too!

It looks like the TC-3 is a "high speed" cassette interface. There is an old scanned magazine that has some information on interfacing the TC-3 to a Sphere computer -- not SS-50 bus, but a 6800-based machine. It doesn't go into detail about how to program the TC-3, but might make interesting reading: http://www.google.com/url?sa=t&sour...ujBsUfZ5k6d8gC_9g&sig2=Io9VEuzwHYkCHlIN9EHO-Q

It looks to me as if most of your mystery boards are pretty simple. We know what the PIA does, so all you would need to do is get some datasheets on the other parts.

JCE

 

[antiquekid3]

So it sounds like this high-speed interface writes 1s and 0s in the form of a high voltage and a low voltage instead of a high frequency and a low frequency? I guess that would explain why they can fit a tape interface into a much smaller package than the AC-30. I'd like to try and get the tape interface working! Does it require special tape, or will most high-quality audio tapes work?

Maybe one of these days I'll trace out the schematic for the TC-3. I wonder what the other connector could be for. Maybe for some control functions? According to that Sphere info, it's not very complicated to program. I'm a little confused though on his software listing. Is that only a partial software listing?

Kyle

 

[MikeS]

So it sounds like this high-speed interface writes 1s and 0s in the form of a high voltage and a low voltage instead of a high frequency and a low frequency? I guess that would explain why they can fit a tape interface into a much smaller package than the AC-30. I'd like to try and get the tape interface working! Does it require special tape, or will most high-quality audio tapes work?

Maybe one of these days I'll trace out the schematic for the TC-3. I wonder what the other connector could be for. Maybe for some control functions? According to that Sphere info, it's not very complicated to program. I'm a little confused though on his software listing. Is that only a partial software listing?

Kyle

Umm, to record on a cassette you will always have to deal with different frequencies, but that's not very complicated; there's a little more to an AC-30 than just a single interface though.