My A500 "project" pics, details, build log?

[djos]

did you plug the keyboard in the right way?




Sorry couldnt resist. ;p

[AmmoJammo]

yes

[Azryl]

You might have also blown the MPU on each keyboard, that is the CPU controller that A500's have on the small circuit board. Bummer if you have! Not easy to find replacements or to replace.

Az

[AmmoJammo]

You might have also blown the MPU on each keyboard, that is the CPU controller that A500's have on the small circuit board. Bummer if you have! Not easy to find replacements or to replace.

Az

I plugged the first poop keyboard (From a REV5 mobo) into my good A500, and its poop... half the keys don't work...

However, I plugged the second "poop" keyboard (REV6a) in, and it works perfectly fine...

So, it appears there is something else odd going on with this REV5 motherboard that doesn't like having a keyboard plugged in.

[Azryl]

I would suggest checking voltages at the keyboard connector. Too high or too low will cause problems and might be the reason behind the original keyboard becoming faulty.

Az

[AmmoJammo]

Voltages seem to be fine, but would an unstable power supply cause the keyboard chip to crash?

I was testing this A500 with an untested power supply, but the voltages seem to measure fine too.

Also, if I plug the keyboard in with the A500 booted up, the machine resets... is this normal? Although its probably a bad idea :p

[Azryl]

Yes, a bad keyboard MPU can cause reboots of the A500. The keyboard has two keymaps for reading the current key pressed, this is why half of your keyboard seems to work and the other half is faulty.

If I remember correctly the MPU is a variant of 6502, with its own ram/rom and I/O functions just for the Amiga keyboards.

Az

[AmmoJammo]

That'll do

[djos]

Score, does the scart do miggy RGB?

[AmmoJammo]

I don't know.... I hope so... the VGA connection doesn't do anything with the Amiga connected... :/

[djos]

Here are the schematics if you need them:

http://dl.dropbox.com/u/71121999/Amiga/SCART_cable_with_LCD_Fix_v2.png

It should work without the resistors and and caps too.

[AmmoJammo]

Nano SwanSID for the C64 arrived yesterday too... first impressions aren't great... but I'll need to listen to it through something other than TV speakers.

[AmmoJammo]

Ok, it does the Amiga 15Khz quite nicely... fantastic! also has S-Video for the C64 and Mega Drive... yay!

And VGA so I can connect it to my PC as a small second monitor (its 15inch) plus composite video for the N64....





But....

There's an issue....

Using the Svideo for the C64, and scart for the A500, the whole imagine is shifted up, and the top 1/4 of the screen gets cut off?

The monitor has no menu adjustments for this...

[AmmoJammo]

turned the monitor off and on again, image came good, but its shaking? :/

edit: there's an option called "VCR" turn it on, image fills the screen, but shakes.... turn it off, clear imagine, cut off at the top.

[djos]

looks like the s-video input isnt truly separate from the SCART input and that is the issue - just get a SCART switch box and use a couple of SCART-S-video/CVBS adapters.

[AmmoJammo]

In PAL: High Res Laced mode, the workbench image is correctly positioned, and fills the screen nicely.

But games obviously don't run in this mode.

However, if I start up in NTSC mode, while still running the PAL workbench res, some games are correctly positioned... ZOOL for example is good... but, other games now have the bottom of the screen cut off... Flimbos Quest being one... :/