Dick Smith Super 80 computer kit

[z80]

thanks for the warm welcome.

 

I cannot tell a lie, I remember alot about this particular machine.

 

The most notable thing was the duty cycle between the video memory scanning and processing duty cycle.

It was novel to say the least

 

From memory the cassette save/load were done in the "dark as well" ?

 

Any ways I willl see if I can dig up any stuff that I still have...I am abit of a hoarder of eproms and the such.

 

 

Of particular interest to me was a game called "crazy maze".

 

have you guys got it?

 

It is worth wire wrapping a machine just to play it LOL

[Robert]

Sorry to say we don't have that game, I found a picture of it

in a catalog, it was made by Matrix Software (a bloke called George).

 

We do have over 100 other games, some for the normal 32x16 super-80,

and some for the 80x24 (vdueb) version.

[Peter]

Welcome to the new member! Good to see another Super-80 fan.

 

Sounds good, I await your progress reports.

 

Hooray! Some success at last!

 

I got up at 5am this morning and tinkered some more and managed to get the Super-80 to boot. Alas the keyboard interface needs some work, the cursor disappers when I plug the Z80 PIO in and there's no keyboard response. I think I'll end up replacing the chip socket for the PIO as a standard measure.

 

I removed several of those crummy IC sockets including Z80 socket, ROM 0, 2513 char gen and some smaller 14 pin sockets. I replaced those with machined pin sockets with the gold plating in the hole. I managed to clean up the video image early on.

 

What made the difference was I think replacing the socket for U18 which drives the relay, LED and vduenable lines and I discovered here that the chip reset line was not held hi as it needs to be, the track was brocken, I could have done this replacing the socket (I doubt that) but the new socket made no difference until I started checking with the Logic probe. I soldered a jumper wire from pin 1 across to pin 16 and this made some difference. Now the test mode kicked in and the VDU, LED and relay started flashing etc. I added the multiplexing chips and the RAM and eventually got the welcome screen Super-80 V1.2 and the flashing cursor.

 

Then the memory corruption bug kicked in. Still a few more things to fix.

 

Cheers,

Peter.

[Robert]

Woot! Well done! Sounds like it will be working very soon!

 

 

The keyboard is an unusual design (software-wise). If a key is pressed,

the entire computer freezes until you let it go. You might have a key down

or some lines shorted to each other.

[Peter]

The keyboard is an unusual design (software-wise). If a key is pressed,

the entire computer freezes until you let it go. You might have a key down

or some lines shorted to each other.

 

OK I'll check that out. Just trying psych myself up to do the memory corruption bug.

 

Those crummy IC sockets are tricky to get off. In the end I resorted to brute force, side cutters, front cutters and a bit of leverage lifts the plastic carrier off leaving the pins till attached to the PCB and then these are desoldered individually followed by a cleanup with the desoldering tool to get the holes clear.

 

How strange, I was just looking at the S80 keyboard as I'm writing this,lo and behold there was a key lower than the rest, I hopped up, gave it a wiggle, plugged in the PIO and I now have a working keyboard! I'm very greatfull for your assistance. Now I'll do the mod to clear up the garbage characters (more now with the PIO plugged in.

 

Cheers,

Peter.

[Robert]

Hooray! That was an easy fix.

 

Now after you fix the random characters, what is left?

 

1. Do the cassette mod, hook up a cassette player, and adjust the trimpot.

 

At this point, you will have a working original Super-80.

 

2. Add a lower-case kit

 

3. New set of eproms.

[Peter]

I'll try and fix the random characters tonight, Overall it seems quite stable, power off - power on cycles give the same result i.e. no need to tweek any chips to get it to run so I'm quite pleased. So there were two broken tracks that I found, 1 from pin 1 to pin 16 on U18 and the other from pin 24 to pin 21 on U26, that was the main problem with failure to boot.

 

About the lower case kit. I thought that I copied the EL-Graphics details from your technical docs? What I have in front of me is the Delux Character Generator from Dick Smith. Is this the same thing as the EL-Graphics upgrade? The Dick Smith one has lots of chips and it looks like it piggy backs some existing chip sockets on the Super 80 board (painfull). I though the EL version had an eprom and a 74LS266 chip? Looks like I need to get the details of the EL version.

 

I'm expecting a new set of EPROMS containing 8R5 version this week. Fortunately the V1.2 Monitor ROM that I had burn't into the EPROM was a good one.

[Robert]

The 8R5 requires lowercase characters, so don't plug it in until you've

got lower case working.

 

The Dick Smith board has an eprom containing 128 characters. The

other 128 are simply reverse-video equivalents, and the other chips

perform that function.

 

The El Grafix is 256 unique characters, which mean a bigger eprom

but the number of support chips is reduced. In my computer, you saw

a special one-off, because by then the Dick Smith kit was no longer

available. I'm not sure but I think it has the 128 normal characters

and 128 reversed characters as if it was like the El Grafix.

 

The Dick Smith kit plugged into 3 existing chip sockets which as you

know will eventually damage them. It's better to just hard-wire

something as it will be far more reliable.

 

Whether you choose the Dick Smith or El Grafix set is up to you,

as is the way you implement it. On my non-working Super-80, I

have both eproms wired up, with a switch to choose which one

I want to use.

[z80]

I also think from memory you can execute a monitor command that selects the block of memory to use as the video memory, and I seem to recall it was useful for seeing memory activity in real time.

 

That was actually a very,very useful diagnostic tool in some situations.

[z80]

found all my stuff ...christ its 25 years old !!!

 

I have my original Dick Smith Technical manual Issue 1 rev B.

Also my issues from Melbourne Super 80 users group newsletters.

 

Is someone able to supply me with the rom code? Am happy to build a clone in my spare time...LOL

 

I would make a 5v only version with static ram (one chip LOL)

 

 

Looking over my notes from the users group adding a 0.22uf greencap on pins 2 and 12 of U15 improves the readability of the default font.

 

Also have full technical manuals for Microbee and Trs80 MK2....I built both in wirewrap and still have them.

 

Oh and found the schemaqtic for a VIC20.....jeez that's old. (like me)

 

can scan and pdf all this stuff if you guys are really keen...

[Robert]

Is someone able to supply me with the rom code? Am happy to build a clone in my spare time...LOL

Read ur PM.

 

can scan and pdf all this stuff if you guys are really keen...

I have my original Dick Smith Technical manual Issue 1 rev B.

Also my issues from Melbourne Super 80 users group newsletters.

Yes please, better than lugging around piles of barely-readable paper!

 

 

I also think from memory you can execute a monitor command that selects the block of memory to use as the video memory, and I seem to recall it was useful for seeing memory activity in real time.

 

That was actually a very,very useful diagnostic tool in some situations.

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