Klyball 600 Build

moonferret
Posts: 7
Joined: Sun May 21, 2017 9:15 am

Klyball 600 Build

Post by moonferret »

Hi Folks!

I'm just finishing up my Superboard II build using Grant's boards but unfortunately, I can't seem to get it working correctly. I've attached a photo of the video output. Basically just getting scrolling gibberish :)

I thought I had read somewhere that there was a trace or two missing from the board. Is this correct? I'm confident the IC's are ok as I've tested most of them in a UK101 board.

Any suggestions?

Cheers,
Dave
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IMAG0834.jpg
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RedskullDC
Posts: 62
Joined: Thu Jul 18, 2013 11:24 am
Location: Dorrigo, NSW , Australia

Re: Klyball 600 Build

Post by RedskullDC »

Hi Dave,

Looks like you have valid video information there, but the sync signals appear to be wrong/missing.

Suggest you check the *HS and *VS signals coming out of U65 (74LS123 pins 12 and 4 respectively).

Ensure that the component values for R33,34 and C7,C8 are correct as per the schematic.
If these are incorrect, it could cause wrong length pulses for *HS and *VS which could result in what you are seeing.

If these appear ok, check the path of *VS and *HS through U70 (74LS03) to ensure they are being mixed into Video Out correctly.
Try adjusting the level of the video signal being mixed in via R58.

Hope this helps,
Leslie
Superboard II - RevD, 8Kb, DABUG monitor ROM.
C1P - RevD, 610, 2 drives, CEGMON.
FPGA C1P/C2/C4. 1-8MHz, 48Kb ram, CEGMON, 16KB Hires.
moonferret
Posts: 7
Joined: Sun May 21, 2017 9:15 am

Re: Klyball 600 Build

Post by moonferret »

Hi Leslie,

Many thanks for the reply. I've just picked up a scope and had a good look at the machine. Following your advise, I checked the sync lines and sure enough there was no horizontal sync. I traced the issue to a flaky 74LS163 at U30 and also a missing trace that goes from U59 to a via about 1cm away.

I'm now getting a stable image full of random characters but no response to reset. Still, it's progress :)

Cheers,
Dave
Klyball
Posts: 230
Joined: Tue Dec 09, 2014 12:53 am

Re: Klyball 600 Build

Post by Klyball »

Glad you got it that far the 600d has auto reset when it's powered up it should go straight to dcwm if the break key is not doing anything check the reset pin state then work back to the key it's a simple curcuit sound like it stuck high
The random chrs screen is a good sign it's working
Replica 600 Rev D:8K,CEGMON
Replica 610 Rev B: 24k,MPI B-51 with Custom Data separator D-13
510 on the bench/replica 582 backplane/replica 470a /replica 555/original 570B/2 x Shugart 851
Ongoing : 630 ,620 ,510,542c,custom 590,SA1200,592,594,596,598
moonferret
Posts: 7
Joined: Sun May 21, 2017 9:15 am

Re: Klyball 600 Build

Post by moonferret »

Hi Grant,

Reset line checks out ok on power up and after holding the break key down. Using a logic probe, I can see some very brief activity on the address & data busses. RAM has been checked ok and I can see that the memory address decoder seems to be working. I've just got some new 8T28's so will swap them out to see if there is any change.

Other than the missing trace near U59, are there any other mods that need to be done?

Cheers,
Dave
Klyball
Posts: 230
Joined: Tue Dec 09, 2014 12:53 am

Re: Klyball 600 Build

Post by Klyball »

Hi Dave, i can't remember if you got the boards from me or Dave

if from dave these are the mods needed , if from me they should be already fixed but check them anyway

Cheers
superboardmods.odt
(385.4 KiB) Downloaded 616 times
Last edited by Klyball on Sun Sep 03, 2017 1:40 pm, edited 1 time in total.
Replica 600 Rev D:8K,CEGMON
Replica 610 Rev B: 24k,MPI B-51 with Custom Data separator D-13
510 on the bench/replica 582 backplane/replica 470a /replica 555/original 570B/2 x Shugart 851
Ongoing : 630 ,620 ,510,542c,custom 590,SA1200,592,594,596,598
moonferret
Posts: 7
Joined: Sun May 21, 2017 9:15 am

Re: Klyball 600 Build

Post by moonferret »

Thanks for the list of modifications. I would never have have spotted them all :) I now have a D/C/W/M prompt. Yay! Unfortunately, I still seem to have a problem. The display is flickering as if a key is being held down. I've checked the switches are all ok but I have noticed the following behaviour...

Disabling the RKB line causes the flickering to stop.
I only seem to be getting activity on pins U3-9 and U2-16. All other keyboard scanning lines are stuck high.

I know it's almost there and probably really obvious but I just can't seem to spot the fault at the moment. Will get some sleep and attack it again in the morning.

Cheers,
Dave
Klyball
Posts: 230
Joined: Tue Dec 09, 2014 12:53 am

Re: Klyball 600 Build

Post by Klyball »

I am confident you would have found them all , that's the best part of osi great schematics make it easy to trouble shoot
Do you have the shift lock switch installed it is needed for proper function
Replica 600 Rev D:8K,CEGMON
Replica 610 Rev B: 24k,MPI B-51 with Custom Data separator D-13
510 on the bench/replica 582 backplane/replica 470a /replica 555/original 570B/2 x Shugart 851
Ongoing : 630 ,620 ,510,542c,custom 590,SA1200,592,594,596,598
moonferret
Posts: 7
Joined: Sun May 21, 2017 9:15 am

Re: Klyball 600 Build

Post by moonferret »

Hmm, still working on this issue. The way the keyboard works on the 600D is different to the UK101. The keyboard matrix is normally low on the UK101 and pressing a key, causes the the relevant line to go high. whereas the the 600 board is normally high. Does this mean I need a different CEGMON to the standard Superboard II? (I realise the UK101 is different again)

I managed to find an actual Cherry MX-Lock switch. wasn't cheap though!
dave
Site Admin
Posts: 710
Joined: Tue Sep 09, 2008 5:24 am

Re: Klyball 600 Build

Post by dave »

It looks like the lock switches are available from TheVanKeyboards.com. These are also useful for Vince Briel's Superboard III kits.

dave
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