An expensive A570 shaped paperweight ?

[Vipersan]

Will I _ever_ learn ..probably not.
I recently bought what is most likely an expensive A570 shaped paperweight.
You dont see these for sale very often so bought it on an impulse.
Claimed condition unknown having sat unused in a cupboard for a long time.
I sort of expected there might be issues ..but not totally dead ?
maybe its not ..I just dont know.
I have a fairly well expanded A500 which is now basically an A500+ ..
Chip and slow ram maxed ..and a KS switcher fitted..
So I can boot with the required 1.3 ..and I assume enough chip ram.
But ..if I connect the A570 to the side trapdoor expansion it will not allow my A500 to boot at all ..
With or without the compatibility switch on or off ..
Or with or without the A570 psu connected or not..
It looks like having the A570 on the BUS is holding the A500 in reset.
I have my doubts it would be incompatible with my A500 with the mods ..but you never know...
Does anyone know of a link to schematics or service manual for the A570.
I would have a go at repairing it if faulty but without schematics ..not a chance even though I am by trade an electronics engineer.
Otherwise I guess it will sit in MY cupboard for a long time ..in the hope I encounter another I can use as reference to try and fix it.
will I ever learn ????
If anyone has any info as to what I might be doing wrong..
Suggestions or links to techinical info please post them up.
But TBH I think I've been had with this one...and it was sold as an unknown quantity (not so sure that was the case)..so no comeback.
rgds
VS

[Vipersan]

Not had any luck finding any service info for this unit.
I did find and downlad a copy of the extended rom dump
391298-01
Apprently the prom/rom is a 23C2100 ..40 pin ..device ...
and wouldn't you know it ..
there _was_ a pin compatible eprom
27C2100.
..and yes my programmer could accomodate this chip.
But ...it doesn't appear to exist.
Maybe once upon a time.
I can find the pdf for it...the chip however appears to have vanished into the mists of time.
So If I _did_ need to replace it....I'm stuffed basically.

[dalek]

ROM is a standard 27c400, I've burned replacements myself.

There is also a FPGA that can be replaced, and a little serial rom that loads it. I haven't dumped that yet but I have the equipment to do it one day. Should in theory be able to program a replacement.

Guessing your Xilinx FPGA is dead. I think I have the schematics, will drag them out later today.

Don't bin it!

[dalek]

Schematics are already on the FTP: ftp://ftp:any@grandis.nu/~Uploads/Un...Schematics.pdf

Does the big xilinx chip get hot? Basically the system stays in reset until the serial prom has finished loading the big FPGA. Check for activity of the serial prom?....

[Vipersan]

Thanks for any help you can offer Dalek.
I dont seem to be able to access the ftp link you uploaded.
Perhaps you could dump any files in my drop box.
https://www.dropbox.com/sh/swg09oz29...sGcephDwa?dl=0

hopefully should work

I'll check the Xlinx later for heat using the finger test.
Not a chip I can program ..but maybe you could make one for me should I need it ?
The very fact that I'm in contact with someone who has the knowledge to help ..gives me hope that this A570 will live again.
kind regards
VS

[Vipersan]

Hi Dalek ..just thought I'd add a couple of pics to show how 'clean' this unit is ..
No visible signs of corrosion etc.
As I said ..the A500 is prevented from booting..
Green led on both units lit ..black screen on the monitor.
I have left it in this state for a good 20 minutes ..and none of the A570 chips feel hot to the touch.
The DMAC chip 390563-02 is just about the warmest thing I can detect by touch...but nothing is 'hot'.
I'll have to dig out my logic probe next to check for activity.
Any specific points to go for first ?
rgds
VS

[dalek]

Hmm - try the EAB FTP search - link should work, but your dropbox link doesn't work for me.

Yep get the logic probe and check the little serial prom for activity - the 8pin? socketed dip. If it's not loading the fpga (e.g. dead fpga or serial prom) then reset will just be stuck low.

When I get a chance I try and get a dump from mine but realistically it will be a few weeks away.

[torsti76]

Maybe start a little more basic and check the voltages of the A570 PSU first before reprogramming PROMs and CPLDs?
It should deliver three voltages, like the standard A500 PSU, i.e. roughly +5 V, +12 V and -12 V.

[Vipersan]

I know this will make me sound stupid ..but could someone advise me how to access the EAB ftp ?
I've never had occasion to use it.
Do I need an accout to use it..and where is the login found ?
cheers.
..also PM'd Dalek my email adress ..just in case.

[lilalurl]

Originally Posted by Vipersan

I know this will make me sound stupid ..but could someone advise me how to access the EAB ftp ?
I've never had occasion to use it.
Do I need an accout to use it..and where is the login found ?
cheers.

http://eab.abime.net/showthread.php?t=43633

[Vipersan]

Originally Posted by torsti76

Maybe start a little more basic and check the voltages of the A570 PSU first before reprogramming PROMs and CPLDs?
It should deliver three voltages, like the standard A500 PSU, i.e. roughly +5 V, +12 V and -12 V.

I have sort of already tested this by swapping psus over with the A500.
The A570 psu works fine on the A500 ..
a crude test but should suffice.
I'll do more accurate tests once I have those schematics.
rgds

[Vipersan]

No idea what I'm doing wrong but using Windows Explorer browser I can at least see directory listings ..but cant go deeper.

Tried Filezilla ..but cannot download anything..
Firefox refuses to even open Grandis

I think that somehow the relevant port 21 is being closed.
I'm no expert with ftp ...but this is very frustrating.
I'm even considering powering up an old XP PC ..to get some access.
doh!

[Vypr]

Most broswers have removed FTP support, you can try downloading Filezilla

[Vipersan]

Hi Vypr
I tried with filezilla already ..it too refuses connection.
Maybe it's my ISP blocking ftp ..
if so I'm basically stuffed.
So unless there is another way to get at these files ????
Can you acces the A570 schematics ? if they are not to large perhaps you could grab them and email them to me ?
I'll PM you my email adress just in case
rgds

[robinsonb5]

I had no trouble accessing it here - so I've uploaded it to The Zone for you.
http://eab.abime.net/zone.php?
(If you've not used it before: http://eab.abime.net/faq.php?faq=vb_...ezone_faq_item )

[Vipersan]

Cheers mate..
joined the zone..
downloaded the pdf.
Now I can undertake an informed investigation once I get them printed up.
The zone will be something I will find useful I think.

[cpiac64]

sorry for stupid question, have you turn go on the a570?

[alexh]

I have a fairly well expanded A500 which is now basically an A500+ ..
Chip and slow ram maxed.
I have my doubts it would be incompatible with my A500 with the mods ..but you never know...

That's where I would look first. The "CDTV" address map is hard coded and if anything else uses up the address space used by CDTV hardware all you get is a black screen..

If you understand tech stuff and you know what expansions you have check for a conflict here :

http://www.l8r.net/technical/cdtv-technical.html

I think it may be ok though:

100000-1FFFFF Space for extra chip memory (Megachip)
C00000-C7FFFF Space for slow-fast memory
C80000-DBFFFF Space

So I can boot with the required 1.3

My A570 used to work with my A500+ (KS2.04). I think all of them came with extended ROM v2.30 to allow you to use KS2.0x+

[Vipersan]

I certainly have considered incompatibility issues ..and rather than remove all my mods..
I have another A500 basic and unmodded on its way to me from Northern Ireland.
It will require some work first I think..but I'm in no rush on account of the lockdown.
I have a IBM clone 286 restoration on the go also atm...so plenty to be getting on with and rather than risk damage to the A570..will employ a little patience and wait a while I think.
rgds
VS

[Hewitson]

Originally Posted by Vypr

Most broswers have removed FTP support, you can try downloading Filezilla

Seriously? That's so lame. Still works perfectly in Firefox.