hi all, just putting out feelers for Dick Smith's Super 80 computer kit enthusiasts/ex

I assembled one in 1983 (I think, very first computer), and for it later assembled various expansion boards. Unfortunately this machine met its demize later in the 80's

I am now seeking to obtain another, working or not, the main premise being that the pcb is in good nick. So if anyone out there has one that they would like to get rid of (at a fair price) please email me at john_dominion@hotmail.com

a fellow Super 80 enthusiast (Peter) is starting a yahoo group for the beast - will keep you posted on that one. He has one he is attempting to make functional.

love to hear from people, their Super 80 experiences etc etc etc Robert informs me that he has a few still functioning! (mostly) and seems to have had a fair bit of experience with the machine.

cheers
Gary

Yes I have 3 of these antiques.

My original one only works on the odd occasion and is now extremely unreliable.

The 2nd kit which I obtained from a friend (for free) in the original packaging still works

And, the 3rd one has the 80-column card fitted and I bought this from somebody, it works well too.

My entire game library is available on the internet, PM me if you want it.

As for emulation of it, you can PM me for that as well.

The Super-80 is now extremely rare and I doubt you will be able to find a new PCB - but I wish you good luck in your search!

Why don't you get Peter to post here instead of the Yahoo group?

Hi Robert n all



I had no delusions about obtaining just a pcb, I enquired at Dick Smith's re the Super 80 and they claimed that they didn't have any record of it (oh well). I had thought that if I can get an accurate image of the top and bottom side of the pcb (the top being obscured by components, of course) using circuit diagrams and a lot of time and patience I should be able to faithfully reproduce the pcb image. Probably very expensive to have one etched though. I had also thought of doing a wire wrap version; it wouldn't quite be a super 80...

No; primarily I had hoped to find someone with an old working or otherwise Super 80, for which the pcb hadn't deteriorated, that they would be happy to sell, and then to take the project from there. It would seem that all of the IC's are still available new (and very inexpensive).



I will suggest it to him, but it may be easier for one vaguely perusing the net for "Dick Smith Super 80" to stumble across a group dedicated to the beast rather than as a sub group of another site (don't you think the poor old Super-80 deserves its own group, hahaha )

Do you have the url of this Yahoo group?

and, what city are you and Peter from? If you live near to me we might be able to arrange something.

The magazine "Electronics Australia" (now defunct) ran the Super-80 as a feature article over a few issues, I can get you a list of issues. The magazine's content was obtained by Silicon Chip which as far as I know still exists.

As for Dick Smith, they were sold to Woolworths and then took over Tandy, so I'm not surprised they no longer have any records. The shop assistants are probably younger than the Super-80! I have the Dick Smith part numbers if you wish to hit them over the head! (they still have the same numbering scheme).

Hi Robert
I emailed Peter and suggested he join 1em, and reply to your questions personally. I don't think that the Dick Smith Super 80 yahoo group is up and running yet.

I live in Sydney (Epping).

Tell me, did you say that your 80 column card is colour?

You live over the other side of the city from me, I guess that's better than the other side of the country!

Yes, my 80-column card is in colour.

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.

Springwood is probably easier to get to, traffic-wise, than Epping is.

What video output do you get?

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?

The screen wiggling is normal because the vertical frequency is about 49 hz and it beats with the 50 hz of your tv, creating a 1 hz disturbance. The only way to get rid of it is to use a good quality green-screen monitor.

I'm not sure about the ] characters, never seen that before. What happens if you turn on the test mode?

I am near Campbelltown.

How much RAM do you have? Are the dipswitches set properly?

Your really starting to show your age

Last time I seen a working one of those was when I was around 18 at Mount Druit Tafe library
Anyway I deal with alot of second hand shops I will keep my eye out for one those


You could also try freecycle http://freecycle.org/display.php?region=Au...uth%20Wales/ACT
You could put out a few feelers on that site

http://freecycle.org/

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.

Yes I can see it

I can see it.

You have 48k ram with 12k of roms, that is good.

I would say that the characters probably are "?", that makes more sense.

OK, now for the dipswitches. (0 = closed, 1=open, X=don't care)

A B C D
1 0 X X TEST PAGE 3E
1 1 X X TEST PAGE C0
0 0 X X START IN BASIC
0 1 X X START IN MONITOR
X X 1 1 16K RAM
X X 0 1 32K RAM
X X X 0 48K RAM

You can set the RAM switches to any position if you think there might be some faulty ram.

The test mode does not use any RAM, it only uses the monitor rom.
What happens is that the screen, the relay and the LED will turn on and off at a slow rate (4 secs and 8 secs).

When you installed the 2532 eproms, did you cut the track as needed?

There is a recomended modification involving a couple of extra ICs.
Once you get the machine to boot up, you should add the modification.

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.

Warm is norm, hot is not.

If the test mode fails to work, you will have to check the voltages and waveforms on the Z80 and the eproms.

The test mode is described in the Technical Manual on pages 31 and 32, although it's not referred to as the test mode.

I don't know if you have the Assembly Manual, if you do, read page 19.

The required modification for 2532 eproms is listed on page 2 of Appendix F of the Technical Manual, and page 16 of the Assembly Manual. Look at the bottom of the board, under U26 (monitor rom), and if you can see a cut track then it's already done.

The other mod, involving some extra ICs, is detailed on page 14 of the Assembly Manual.


edit: oops, i forgot to welcome you to 1emulation!!

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.

The Assembly Manual comes with the kit, and therefore has no part number of its own. It has the kit's part number, K-3600.

The other books I have are:
* Monitor Handbook
* B-3606 Dick Smith's First Book of Super 80 Programs
* Software for the Super-80 Computer
* The assembly manual for the Printer Interface

Here's my complete list of Dick Smith part numbers:
K3600 SUPER 80 COMPUTER KIT
K3601 COMPUTER KEYBOARD
K3602 TAPE BASIC
K3603 OPTIONAL IC SOCKET PACK
K3604 ROM BASIC
K3606 S100 EXPANSION KIT
K3607 SUPER 80 DELUXE CHARACTER GENERATOR
K3610 PRINTER INTERFACE FOR THE SUPER 80
B3600 SUPER 80 TECHNICAL MANUAL
B3602 SUPER 80 BASIC HANDBOOK
B3606 FIRST BOOK OF SUPER 80 PROGRAMS
H2515 MOULDED PLASTIC CASE FOR THE TRANSFORMER
H3200 SUPER 80 CASE
H8402 SUPER 80 CIRCUIT BOARD
M2325 TRANSFORMER
A2461 MOLEX CONNECTOR FOR TRANSFORMER SECONDARY
P4160 16-PIN SOCKET FOR RAM
X1186 16K EXPANSION RAM
X3607 HORSE RACE GAME
X3790 DEBUG-80 SUPER-80 DEBUGGER DISASSEMBLER
X3791 EDIT-80 SUPER-80 EDITOR ASSEMBLER
X3792 DUNGEON DILEMMA GAME

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?

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.

If you're using IC sockets they will very likely be causing problems.
Check the voltages both at the pin and on the board to be sure.

I have the EA article but it's exactly the same as the Assembly Manual.

Perhaps we need to organise a visit sometime, I have a spare Assembly Manual.

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.

No, I meant coming to your place. I have a spare 2513.
I have a bunch of spare chips somewhere, could be a 81LS95 there, who knows.

It's a pity you don't have the lowercase kit, then you wouldn't need the 2513.

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.

Would Sunday the 19th be ok?

I seem to recall that a 81LS97 could be used in place of the 81LS95.

The lowercase kit consist of one eprom and what looks like a 74LS166.

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.

We used to call them "dip headers" and they were available at any parts store. Well, back then they were.

I'll send you an email shortly.

What chip position (Uxx) is the missing 81LS95 used in?

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.

Aha! Unless you are planning on using the Printer Interface card (which contains a serial and a parallel port), I wouldn't worry about the S100 area.

If the 0v pin (pin 8) of U18 is not zero volts, then it's not grounded properly.

There are some mistakes in the circuit diagram around U18 (on my copy at least).

Make sure that on the left side of the chip it shows pins 2,7,10,12,15,5 and the right side should show
3 D0, 6 D2, 11 D3, 13 D4, 14 D5, 4 D1.


edit: I've sent you an email, and I removed the address from your post, to spare you from the spammers. :)

OK. I should've checked the grounding of that chip, there seems to be a lot of gunk on the pins too and this could be afftecting the operation. I'll check the schematic as you suggest. I think I've noticed a few discrepancies between board and shematic.

There's another suggested mod that I made, it improves the cassette recording. I'll show it to you on my visit.

OK. Sounds good. I've got a few old data cassette devices, a VZ300 and a Small Sony if I can find that. I've got an Atari but no tape bay cover. Of coarse I've never tried these so hopefully they still work.

The recommended cassette player was one of those flat portable ones from yesteryear. You could have batteries or run it off a power cord.

Got your email, thanks!

Do you have a working composite b/w monitor with a RCA socket as input? If so I could bring one of my super-80's over for you to look at.

I know the ones, probably garage sale jobs these days. Do you think the VZ300 job will work then?

No worries. Most Street Directories cover Blue Mountains, I'll email you some directions.


I'd love to see a working one. I've got a Micobee amber screen (I think) sitting next to me, could be green. will that do? It's got RCA input.

Hopefully your monitor and cassette recorder will work, won't know until we try it I guess. But need to get yours to boot up first of course! Any progress?

The Microbee monitor works, strangest thing is though the picture artefacts are very similar to the VHF modulator output (sans noise) there's no door step and the character grid is a little snakey. I think there's some interference somewhere in the video generation ciruit. There's also some sort of scrolling from bottom to top.

At this stage I'm confident that the video circuitry can be debugged and tuned. I can't get the test mode to work at all so I suspect that the CPU circuit isn't quite right. I'll concentrate on that in the short term.

This is my plan of attack.

1. Verify ROM images
2. Verify CPU is functional
3. Check address and databus integrity (using DMM)
4. Check memory decode logic

What I would expect to find is that some logic chips may be defective and or the pins aren't making good contact in the sockets as you suggested earlier. I'm wondering if I should pull all the chips out again and start assembling from scratch following the guide. Before that I'll do steps above.

And, you might be able to compare some waveforms to my computer.

Let me know how things turn out

At least I have a few spare TTL chips. One thing that I haven't asked you is if the PC board (out of the box)needed any mods before it worked apart from the link for BASIC in ROM and the suggested improvements.



That's a good idea. Especially the video circuit, something's not right there.

Yes, that part of the computer has far more chips than it should have had.

btw, does Garos have a Super 80 as well? He seems to have disappeared...

I agree, it seems the most complicated part of the system. I've pulled all the chips and started rebuilding. I've found an initial problem with the signals. The output of U30/pin 11 is supposed to be 15 kHz odd, but mine is 32kHz, I've swapped the two chips involved and still get the same value. I'm wondering if the manual is wrong. U30 is a 74LS86 (XOR) (combining 15K and 32K sigs) and U36 is a 74LS92 (div by 12) Can you check yours for me? Up until this point all signals are correct, I'll have a closer look tonight but it's quite suss.

He had one and he's keen on getting another.

Unfortunately all my test gear is over at my other house, as is my TTL manual.

However, on my circuit diagram I have marked all the theoretical frequencies, so let's see how we go. All frequencies are HZ.

U30 pin 11 and 13 = 15625; pin 12 = 31250.
U36 pin1 = 93750 ; pin 9 and 11 = 31250 ; pin 8 and 14 = 15625 ; pin 12 = 7812.5

Some more if it helps:
U31 pin 1 = 7812.5 ; pin 9 = 3125, pin 8 and 9 = 1562.5, pin 12 = 781.25
U28 pin 1 and 3 = 15625, pin 2 = 31250
U39 pins 1 and 2 = 15625
U38 pin 12 = 375000, pin14 = 197500, pin10 = 93750, pin2 = 46875, pin4 = 15625, pin6 = 781.25
U43 pin 10 = 390.625, pin12 = 195.3125, pin14 = 48.828125

Hopefully there's not too much crap in that lot!

Hi Guys,
I made a reply but it vanished... oh well

as I mentioned afore, I built an S80 in 1983 which I unfortunately ditched in when it became disfunctional
for it I built two graphics cards, the second being the 80x24 b&w card

I have been trying to decide whether or not to try to reproduce a super 80 (tis about $150 to have a 30x30cm double sided board made) or to design and build my own machine based on pre 1980's technology.
I have been looking into the latter and am becoming more and more interested. The 68000 came out in 1979 and sounds like an excellent chip to become familiar with, though being 32/16 bit increases the complexity of the circuit. Anyhow, will keep you posted.

I am away on Sun 19th, but hope you guys have an enjoyable and successful time.

I intend to do just that. It's a pity you threw out the broken Super 80, oh well. Good luck with your new project.

My super 80 has an interesting mod... instead of 4116's it has 4164 (64k x 1) RAMs. It meant I could get rid of the -5volt supply and only have 8 ram chips, and I get 52k of RAM.

Most of those signals check out OK on the CRO although there's a lot of noise, very short negative spikes that's fooling the frequency meter and I'd say is responsible for the odd behaviour of the video display.

One really problematic test point is U28 pin6 the manual says it should output bursts of 6mHz at 750kHz. I can't see how this can possibly be correct as one input is constant HI (derived from BusAck#) which comes from the CPU, do you have anything on your diagram? I'm wondering if U28 Pin 6 should be connected to U28 Pin 10 which is a 6MHz input? I can't see how Busack# could ever produce a 6MHz signal if the CPU is runnng at 2MHz.



That sounds interesting, I've got a bundle of 4164's I've read about a few mods on arcade game PCBs that involve this.

I hope you have a scanner or photocopier, there's a few things you may wish to copy that i'll bring with me.

The spikes are absolutely no surprise, considering the mishmash of unbalanced gates with no consideration of propagation delays whatsoever.

U28 pin 6.. hmm I couldn't say exactly what it is, there are 12mhz and 3mhz signals going through U76 (a pair of flip flops) which goes to U28 pin 5. The BUSAK signal will be at the vertical frequency (48.8hz) and will only be present when the screen is ON, at U28pin4. U28pin6 will be these two signals NANDed - whatever that results in. Perhaps bursts of 3mhz at 48hz. Whatever, it is the signal that allows the video circuitry to read the RAM during screen refresh times. Btw, this exact part of the system is what needs a mod I will bring to you. Once things are running, you MUST add this mod.

I was wrong about the u28 pin6 connection I should've said pin4 as pin 6 is the output. Anyhow I have a clear picture of @s and ?s alternating on the screen (with the bars from faulty 2513) the poor picture quality was a dodgy socket, wiggling u28 cleared that up. Here's what I get:

1. @s and ?s alternating on the screen.
2. verticle solid bars over the top of each char (faulty 2513)
3. top 3 rows are snakey
4. there's some induced hum scrolling from top to bottom and mysteriosly it's at 50Hz (now what could that be from? need I ask? ) I see it on the scope to.
5. The reset circuit is totally shoddy, the 4.7K pullup isn't doing it's job and there's this 50Hz hum again coming out of the ground signal. I suspect the CPU is in a constant catatonic state as a result.
6. I can't get the VDU to blank, probably related to the hum.

That's as far as I've got so far. Need to socialise some.

I reckon if I can eliminate the mains hum from the ground circuit which is leaking into the reset and video circuit a least the video will be as near to perfect as it can be. And then the CPU may get a chance to clock a few more cycles.

BTW: I have a scanner. things are looking up.

Hopefully the big filter capacitors are doing the job. If they are original ones they possibly need replacing. Make sure the ground circuits are properly connected throughout the board. The transformer windings must be correctly phased.

The video display is not likely to improve much, the design of that area is a total abortion.

We just need to get the CPU to start working.

Visiting Peter today, first time I ever meet anyone from the Internet.

I'll report any progress when I get back. Wish us luck!

Hi guys
can't wait to hear how it went, did the S80s sing? (is Peter a mass murderer?)

I have just begun a 5am shift at Parkes observatory, but we return to Sydney this morning.

Gary