Acorn A500 video problem

[razz177]

Hi
Can someone answer me does the A500 recharge the batteries or am I alright with standard Duracell AA Batteries,
I have put these in and now got it booting up from the hard drive, but with a pink screen & without a mouse I am stuck for now, waiting for a new 9pin plug for mouse. I am about to open up the RGB to scart lead.

[IanS]

Not recharchable.

Do you have a working keyboard? Have you done a delete-power on (press delete, power on, wait for the risc os banner or the desktop before releasing delete). Try R if delete does nothing (or is labelled differently on the A500 keyboard)

If you have a working floppy you can try warfarin to simulate the mouse - viewtopic.php?p=231421#p231421

In you earlier posts you said it was running RISC OS 3, is that correct? I thought there were some difference between A500 and production Arcs that might cause issues. Maybe not.

[razz177]

Hi IanS
Yes I have a working keyboard, and the computer works I have ordered a new 9 pin D connector for a mouse I have, the A500 is running RiscOs 3

[razz177]

well this looks a mess.

[razz177]

Not recharchable.
a500-rtc.PNG

Do you have a working keyboard? Have you done a delete-power on (press delete, power on, wait for the risc os banner or the desktop before releasing delete). Try R if delete does nothing (or is labelled differently on the A500 keyboard)

If you have a working floppy you can try warfarin to simulate the mouse - viewtopic.php?p=231421#p231421

In you earlier posts you said it was running RISC OS 3, is that correct? I thought there were some difference between A500 and production Arcs that might cause issues. Maybe not.

well you would not believe it ordered new plug , when searching for another video cable and found the mouse (great stuff)
Running RiscOs 3.10 30 April 1992

[SKS1]

but with a pink screen ... I am about to open up the RGB to scart lead.

Is that perhaps down to the A500 outputting sync-on-green, but your monitor doesn't want that?

[razz177]

but with a pink screen ... I am about to open up the RGB to scart lead.

Is that perhaps down to the A500 outputting sync-on-green, but your monitor doesn't want that?

I am not sure I am using a AKF 11

[IanS]

Could the A500 be upgraded to a VIDC 2?

Does anyone know what the changes for video output drivers was, was it just hardware, or differences in the sw level? Answering my own questioin, seems to be hw level - https://chrisacorns.computinghistory.or ... asheet.pdf Section 6.5/6.10.

What VIDC does you machine have?

SKS1 is probably right, it's the sync-on-green causing the purple screen - viewtopic.php?p=358907#p358907

[SKS1]

Does anyone know what the changes for video output drivers was, was it just hardware, or differences in the sw level? Answering my own questioin, seems to be hw level - https://chrisacorns.computinghistory.or ... asheet.pdf Section 6.5/6.10.

Developing Arthur, then RISC OS 2, we used to have different ROM builds for A500 and the Archimedes systems. Bit surprised that there's a RISC OS 3.1 for A500 as I thought they'd have retired the A500s by then.

[razz177]

Does anyone know what the changes for video output drivers was, was it just hardware, or differences in the sw level? Answering my own questioin, seems to be hw level - https://chrisacorns.computinghistory.or ... asheet.pdf Section 6.5/6.10.

Developing Arthur, then RISC OS 2, we used to have different ROM builds for A500 and the Archimedes systems. Bit surprised that there's a RISC OS 3.1 for A500 as I thought they'd have retired the A500s by then.

This is how it was when I bought it some years ago now, this was working right when I got it as I would have checked it before putting it away.
I have tried two different rgb to scart leads on it one from my BBC with the resistors in and one that is in the picture, I pulled all the pins and got rid of wires that were hanging out (just to make sure none were touching) I also noticed that the white wire going to pin 6 in the din plug is not connected in the scart plug , I have been searching all afternoon on line for a proper diagram of the scart lead for the A500 without Joy, I am sure I read somewhere that someone had modified a BBC lead to do the job but I cannot find it.
The mouse I found while searching for another lead works great , but there was no lead in the box with it.
Thanks for your help and suggestions Ray

[razz177]

Not recharchable.
a500-rtc.PNG

Do you have a working keyboard? Have you done a delete-power on (press delete, power on, wait for the risc os banner or the desktop before releasing delete). Try R if delete does nothing (or is labelled differently on the A500 keyboard)

If you have a working floppy you can try warfarin to simulate the mouse - viewtopic.php?p=231421#p231421

In you earlier posts you said it was running RISC OS 3, is that correct? I thought there were some difference between A500 and production Arcs that might cause issues. Maybe not.

HI Yes I have added photo's & Roms List , How do I stop NET on the Icon bar computer always boots with netstation error the only thing I have not tried is killing/unplugging the Network roms , I have also took other pictures as I stripped it to clean it.

[razz177]

Not recharchable.
a500-rtc.PNG

Do you have a working keyboard? Have you done a delete-power on (press delete, power on, wait for the risc os banner or the desktop before releasing delete). Try R if delete does nothing (or is labelled differently on the A500 keyboard)

If you have a working floppy you can try warfarin to simulate the mouse - viewtopic.php?p=231421#p231421

In you earlier posts you said it was running RISC OS 3, is that correct? I thought there were some difference between A500 and production Arcs that might cause issues. Maybe not.

HI Yes I have added photo's & Roms List , How do I stop NET on the Icon bar computer always boots with netstation error the only thing I have not tried is killing/unplugging the Network roms , I have also took other pictures as I stripped it to clean it.

why do my pictures turn sideways it just makes it hard for people to read them.

[steve3000]

Nice A500, I’m currently in possession of its older sibling #249.

At least on #249 the RGB out is exactly the same as on the BBC micro. I just use a standard BBC micro to SCART lead.

[steve3000]

And I doubt you’re issue is due to sync-on-green, because that problem usually only surfaces when you have split H and V syncs going to a VGA monitor - but you’re using a standard 15khz screen with composite sync. I suspect your SCART cable just has a break in the green wire, or green is wired to the wrong pin. You could try swapping round the R G B lines in your SCART plug to confirm.

[razz177]

a500-vidc.PNG
Could the A500 be upgraded to a VIDC 2?

Does anyone know what the changes for video output drivers was, was it just hardware, or differences in the sw level? Answering my own questioin, seems to be hw level - https://chrisacorns.computinghistory.or ... asheet.pdf Section 6.5/6.10.

What VIDC does you machine have?

vidc12.PNG

SKS1 is probably right, it's the sync-on-green causing the purple screen - viewtopic.php?p=358907#p358907

Here is a picture of motherboard

[IanS]

Here is a picture of motherboard

Isn't that just the picture from here - https://chrisacorns.computinghistory.or ... /A500.html

[razz177]

a500-vidc.PNG
Could the A500 be upgraded to a VIDC 2?

Does anyone know what the changes for video output drivers was, was it just hardware, or differences in the sw level? Answering my own questioin, seems to be hw level - https://chrisacorns.computinghistory.or ... asheet.pdf Section 6.5/6.10.

What VIDC does you machine have?

vidc12.PNG

SKS1 is probably right, it's the sync-on-green causing the purple screen - viewtopic.php?p=358907#p358907

Here is a picture of motherboard

sorry that's not my motherboard it is one I have checked against mine

[razz177]

Here is a picture of motherboard

Isn't that just the picture from here - https://chrisacorns.computinghistory.or ... /A500.html

Yes sorry used it to see if there was any differences I must have deleted mine by mistake here is one before I removed it

[steve3000]

Looks like there’s a lot of patching/modifications going on between your VIDC and the RGB socket - could something have worked loose here? Can you confirm whether or not there’s a signal coming out of the green pin on the RGB socket?

[razz177]

And I doubt you’re issue is due to sync-on-green, because that problem usually only surfaces when you have split H and V syncs going to a VGA monitor - but you’re using a standard 15khz screen with composite sync. I suspect your SCART cable just has a break in the green wire, or green is wired to the wrong pin. You could try swapping round the R G B lines in your SCART plug to confirm.

checked continuity thats OK , Red - pin 15 green - pin 13 blue - pin 11

yellow pin 20 black pin 17 / there is a white wire in the plug that is not attached but it is soldered to pin 6 in the din plug

[razz177]

Looks like there’s a lot of patching/modifications going on between your VIDC and the RGB socket - could something have worked loose here? Can you confirm whether or not there’s a signal coming out of the green pin on the RGB socket?

Note sure how to do that , I do know it makes no difference when i disconnect the green wire in the scart.
I looked around when I cleaned it and did not find anything loose , I did get a good picture for a while after cleaning keyboard and before I refitted it's case, then back to pink.

I can strip the computer again to check it will need it again for some more cleaning.