Peter

OK. 81LS95 is missing from either U4 or U12, I have one of them but removed the chips for testing. This is the S100 interface. I think the 74LS174 is faulty, there's lots of noise coming out if the 0V pin and this drives the relay transistor and LED etc.

Sunday 19th would be OK. Email me at ************ and I'll send you my details etc. I think that's what it says in the manual. I couldn't find the 74LS795 in any catalogs it might be just as scarce. Perhaps the lowe case board could be made up from scratch. I'm looking for double ended machine pin headers for this sort of thing. I'm not sure what they're called though.

Sure, that would be great. Do you come up this way much? I'll be flat out next week end (11/11) but following (18/11) should be OK, if you drop me an email I'll send you my address etc. Let me know what you want for the chips. How complex is it? If there are no obsolete parts I could cobble one up.

Ok. The output pins (bit 5 and 6) on the 2513 are constantly hi (pin level) this carries on over to the 74LS165 shift register. At this stage I think the 2513 is cactus. I'm missing an 81LS95 chip too. The 74LS795 is a substitute but that looks scarse too. Yes, I'm not sure I can get to Campbeltown any time soon, I'm in the middle of house renovations. That's consuming a lot of my time lately.

Robert, I've made a bit of progress with the Super-80. After swapping out the 1 of 8 decoder IC 74LS138 I get a random jumble of characters on the screen but there are white solid verticle bars superimpossed on top of the characters at each and every character position. It looks like the Char Generator is outputting 1's for the MSBs (bits 5 and 6). I might have to make one from an EPROM or locate one on the net somewhere. I was hoping this chip would be OK. Cheers, Peter.

Wow, that's a comprehensive assortment, thanks for that. Do you have the EA articles? I'm wondering if they're worth buying? Or is it just a rehash from the technical manual?

OK. I found that, I had read it before but forgot about it. It's a bit vague but it does make sense now. No, I have the Technical Manual (B 3600) and BASIC Handbook (B 3602] I'd like to see the assembly manual I'm assuming its cat# B 3601. Strangely though the tech manual has "assembly manual" at the top of each page. I think the original owner may have misplaced the Assembly Manual. OK. I found that too but the work looks dodgy, a couple of traces have been ripped off (fried perhaps) and replaced with point to point wiring, the track in question has been cut. I put the logic probe on the CE pin for U26 and it's never in the lo state (selected) same pin on U33 oscillates. Looks like I need to do some intensive work with logic probe and tracing with continuity tester. Cool, I'm impressed with the presentation, I'll have a snoop around when I get time. Anyway I really appreciate your help with this, to me it's invaluable! I've always held a fascination for the Super-80 and I'm determined to see it working. Cheers, Peter.

OK, I've set it for 16K RAM 1 0 1 1 My technical manual makes no mention of the test mode. This is amazing. My LED needs work, the tracks have lifted from the board. I'll use a Logic Probe to see whats happening there. Actually I didn't build the Super-80 I got it from a friend who lived in Eagle Vale back in 1991 or so. I dont know about cutting the tracks for using the 2532 EPROMS. Can you elaborate on that? I'd really like to know about the other mods that are required. My Z80 CPU is quite warm to the touch, not scorching though but I wonder if that's normal? Cheers, Peter.

Robert, Thanks for that info. So I wont panic about the 1 hz difference. I've got an old microbee amberscreen monitor I've been meaning to hookup and I might try that today. I'm assuming they're ] chars but they are a little blurry, could be ?'s . The original RF Modulator is dodgy so i've hooked a new one up and this produces a very black screen with little noise. The orignal is a snowstorm. How do you turn on test mode? I don't know about that. I'm curious. Is it a dip swtich thing? Mine has 48K RAM and I just took delivery of an entirely new batch of 4116's to replace them if they are faulty. Chances are they may have been zapped over the last 20 years. I wonder if the Char Gen chip is OK. It's been a while since I looked at the dip switches, Can you remember what the correct settings are? I have 48K RAM with BASIC in ROM. By the way, can you see the yahoo group? Cheers, Peter.

The video output seems to be ] characters, 32x16 of them. Very snakey which might indicate some diodes need replacing. There's also a constant scroll from bottom to top and looking at the video signal on a CRO the entire composite signate shifts in voltage, kind of jumps on the CRO screen. I wouldn't say it's mains hum since it low frequency, something like 0.5 to 1 second period. Where abouts are you situated?

Hi Robert, I'm a fellow Super-80 enthusiast, Gary has mentioned me! I have a non functional Super-80 and I'm keen to get it working. we'll I get some video output and that's about it. I've been reading the posts on the Super 80, I'm not sure what's up with the yahoo group but I believe it should be working at http://tech.groups.yahoo.com/group/dick_smith_super-80 BTW: I live in Springwood (Blue Mountains) I'm wondering if you have any notes and errata you could share with us. Actually I'm interested in knowing if the EA articles had any of those details before I shell out for the articles. I've got a couple of the original manuals too. Cheers, Peter.