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

[djos]

but haven't you changed it to a 8372AB?

I'm not using it ATM as the it needs 2mb chip ram to work and Tomthul is still working out the kinks in my 2mb chip ram trapdoor card.

[djos]

oh...

then why is yours NTSC?!?

I'm really not sure to be honest, kinda puzzling.

Hehe, sneaky

[djos]

That is weird, my GBS doesn't like pal at all?

I did discover tho that the NTSC output works with my Samsung LCD monitor via miggy-VGA adapter but PAL doesn't. I'm thinking of making a sync stripper for my GBS to see if that fixes my PAL issue.

Btw, I did some mucking about today, I used Miggy -> scart -> RGB-Component transcoder -> GBS-8220 and I was able to use PAL & NTSC modes with no issues. I suspect that the built-in sync separator in my Component transcoder may have helped?

So then I tried using H/V-Sync + RGB direct from my Miggy to the GBS but couldnt get this to work at all for some reason???

[djos]

I do believe one of the sync signals is reverse polarity, positive instead of negative, or negative instead of positive.

I forget which one, but that's why it doesn't work

That explains a lot!

Im thinking of making a Miggy to Female VGA lead for the GBS just for fun and to see if it works.

[djos]

oh...

then why is yours NTSC?!?

Found the cause and Fixed it, the previous owner of my mobo had joined jp4 together - I fixed it today and now my miggy defaults to PAL and the correct clock speed 7.09Mhz.

I also found that the below settings on my GBS work fairly well with both PAL and NTSC:

Tweaked for: 800x600 res:
HPOS 50
VPOS 14
HSIZE 50
VSIZE 56
CLAMP ST 97
CLAMP SD 00

EDIT: and just discovered that PAL works with the GBS defaults now my miggy is running @ the correct clock-cycles! :p

[djos]

ADF it for us anyway mate? :cool:

[djos]

Lol

[djos]

1985, that was a good year :-) I was 10 years old LOL /feels old, runs off and hides in the corner

Same here! :biglaugh:

[djos]

Old people :p

Young Whipper-snappers!

Get off my lawn ....

[djos]

Lol, nice work anyway AJ. :cool:

[djos]

Not ideal, where the file names too long?

Btw, if you are using SCSI make sure you get a proper external active terminator and at least a dual shielded SCSI Cable - back in the 90's when I was a Macintosh Tech, I solved 98% of stability issues by replacing the customers cheap a$$ SCSI cables with decent ones and using real terminators instead of the built in Termination on everything from Scanners to external Hard Drives.

[djos]

Only The last scsi device in the chain should be terminated, I also found (back in the day) that making the closest device to the controller say #2 and the next device in the chain say #3 helped a lot to.

[djos]

I've seen scsi cause all sorts of random crashing and data corruptions.

If your cd rom is physically last in the chain, then only it should be terminated and have the highest device Id number.

[djos]

Yeah that all looks good - only thing to consider is, is the the HDD part of a single chain or is it on it's own internal chain.

You can tell by the cable coming from the controller, if it loops back to the PCB it's likely that to cut costs there is a single chain and the only thing to terminate is the external device.

[djos]

no loop back?

http://amiga.resource.cx/photos/gallery/a590.jpg

internal cable just goes from the PCB to the HDD.

Ok, yep the internal drive does need to be terminated then - if you can find an internal active terminator that would be best practise. they usually look like this:



although most decent scsi HDD's did use active termination. :p (impossible to know for sure tho unless you can find a datasheet online)

[djos]

As I mentioned before, the HDD has inbuilt active termination... can either be either bus powered, self powered, or provide power to the bus...

http://ftp://ftp.seagate.com/pub/acrobat/install_guides/hawk/67471c.pdf

It's set to self powered at the moment.

Ok, that's how i'd have configured it too - great manual, you dont see them like that anymore!

how thick and flexible is the scsi cable for the CD-ROM drive? the very flexible onse where usually only single shielded and very prone to issues, dual shielded or better is the best option (I have a couple that might be of use - only issue is they use the HD50 connectors).