CDTV and A500 Harddrive controller

Hi,

Sorry for the long story, but here I go:

I bought a CDTV a few months ago and am planning to turn this into my ultimate gaming machine that would allow me to play all my fav 90s games using whdload/jst from HDD or CD.

So far, I've installed ECS and Kick3.1 + extended roms.

Now I needed some extra RAM and a harddrive. Some dedicated CDTV products exist but are hard to get hold of and expensive.

I got inspired by the info on cdtv.org.uk that signals 7-80 from the diagnostic connector are basically the same as 13-86 on the Amiga 500 side expansion. Cool! So I bought a GVP Impact A500 HD8+ Series II with 4MB RAM and 80MB Harddisk and a batch of diagnostic slot connectors on e-bay. I also got 80 leads using 2 40-lead IDE cables and started soldering the two together.

Of course things never work out as they plan, so I can't get the bloody thing to work.

I've also read that you shouldn't use CFGIN from diagnostic connector but instead make a jumper to pin 72 of the DMAC. This doesn't seem to work either.

Here's the results I get using various connections of CFGIN and CFGOUT (not connected, connected to diagnostic or to DMAC):

* The CDTV doesn't boot anymore nor does it show the CDTV animation screen
* It shows the animation screen in red, but doesn't boot from either CD or Harddrive
* It boots but doesn't recognise the harddisk or extra RAM
* It doesn't boot from CD, but when I insert a floppy I get a red screen saying that device with autoconfig ID 2017 is defective
* It boots, but doesn't recognise the extra RAM and or harddrive with sysinfo, hdtoolbox etc...

Here are my thoughts about what could be wrong:
- Conflict with the DMAC ???
- Conflict between HD and CD ???
- Conflict between the GVP ROM and CDTV extended ROMs ???

Even if I wouldn't be able to autoconfig at startup, I'd be keen for any info on how to use the harddrive and allocate the RAM with software under WB3.1

Obviously what I'm trying to do here is not straightforward, so I'm not expecting anyone to come up with a direct solution. But I'm quite keen to get this to work and if I do then this would open up lots of possibilities for other CDTV users, as these GVP devices are up for grabs on e-bay cheap!!! And perhaps this could even work with GVP G-Force 030 (these are cheap!!!) or other A2000 accelerators etc...

Any help appreciated,
Roland

[alexh]

Curious to know where you got your new PROM's?

Originally Posted by alexh

Curious to know where you got your new PROM's?

ebay.co.uk. 7 weeks ago

[Twanger]

Hi there,


nice board!

I have a problem with my new project and maybe someone can help me:
I´m trying to connect a A590 to the CDTV´s diagnostic port. So far I think the only thing that is missing is the CFGOUT signal which is not connected at the CDTV. Where can I get this signal from? I read something about the DMAC connector number 72... is it true and which one is no.72 at the DMAC (how do I count to find this pin?).
Is there anythin else I have to consider???



The following already works: Autoboot OFF, 0,5MB at the A590 selected => Workbench starts (From disk drive) and shows the additional 0,5 MB mem from the A590; Harddisk does not work (I think due to the missing CFGIN signal).
When I select 2MB at the A590 the following error message appears: [FONT="]"Software failure: makedir Program failed (error #8000000A) Wait for disk activity to finish"


Thank´s a lot!
Best regards,
Twanger

[Jope]

Hmm, I personally can't recommend to do this kind of hacking unless you know what you're doing or have the ability to google up what you don't know.

But anyhoo. Look for the dimple on the PLCC package, that is pin 1, you count anti-clockwise from that dimple.

I'll merge this thread with the other one concerning the CDTV and connecting an AmigaBus peripheral to one.

Good luck with your project!

[Twanger]

Originally Posted by Jope

Hmm, I personally can't recommend to do this kind of hacking unless you know what you're doing or have the ability to google up what you don't know.

But anyhoo. Look for the dimple on the PLCC package, that is pin 1, you count anti-clockwise from that dimple.

I'll merge this thread with the other one concerning the CDTV and connecting an AmigaBus peripheral to one.

Good luck with your project!

Thank´s - didn´t see the other topic before...
What you are explaining is exactly how I thougt - just wanted to get sure

@Doelen:
Hey cool; seems like you and me had the same idea at the same time - but unfortunately also the same problems... But wasn´t it that way that the greatest inventions had come up like that :-)
I wrote to that guy who hosts cdtv.org.uk; let´s see if he got a clue...

In the meantime I received the schematics of the CDTV and found out that the CFGOUT lies at pin71 on the DMAC! (CFGIN is at pin 72 - but what should CFGIN be useful for; I think you only need that when you want to connect on more device)

[Jope]

The DMAC is supposed to be connected to the Zorro bus, so it get's it's configin from the motherboard and it's configout is connected to the next zorro device's configin pin..

Where does the cfgout pin go in the schematics? Is it tied high or low or what happens to it? (can't remember how it should go)

Check that, cut it if it goes somewhere and then connect the cfgin of your next zorro device to the dmac's cfgout and the next device's cfgout goes to where the DMAC's cfgout used to go.

Recommended reading: Commodore Amiga Hardware guide (also in digital form on the developer CD, I think).

[Twanger]

Hmmm - I´ll look that up and try that.
I also thought that maybe the CDTV´s internal CD-Rom might be the problem - the CD-Rom device should also get a CONFIGIN from the CDTV, shouldn´t it?

[Jope]

The DMAC on the CDTV's motherboard is what's controlling the CD-ROM (look at the schematics you have!).

If you don't set up a proper autoconfig chain, then you have no chance to autoconfigure the other DMAC in your A590.

[Twanger]

Originally Posted by Jope

The DMAC on the CDTV's motherboard is what's controlling the CD-ROM (look at the schematics you have!).

If you don't set up a proper autoconfig chain, then you have no chance to autoconfigure the other DMAC in your A590.

Well, It´s not that simple. The CD-Rom is NOT controlled via the CFGIN or CFGOUT of the DMAC.
The CFGOUT is connected to the diagnostic port (my schematics say that; I know others say that the CFGOUT is NOT connected...), and the CFGIN is also connected to the diagnostic port where it is finally grounded...

[Jope]

Originally Posted by Twanger

Well, It´s not that simple. The CD-Rom is NOT controlled via the CFGIN or CFGOUT of the DMAC.
The CFGOUT is connected to the diagnostic port (my schematics say that; I know others say that the CFGOUT is NOT connected...), and the CFGIN is also connected to the diagnostic port where it is finally grounded...

You are correct, the CFG pins are in no way used for CD-ROM control. However I didn't imply that. Actually, reading my replies, I've never even hinted that! I've been talking about autoconfigure all the time.

What I tried to say is that DMAC is there because it is the CD-ROM controller of the CDTV. (just like the DMAC in your A590 handles the Zorro <-> SCSI-chip and Zorro <-> XT-IDE-bus[*] communication.)

CFGIN and CFGOUT are used for AutoConfiguration of the devices on your Zorro bus.

The DMAC is part of the autoconfig chain inside the CDTV, so you really need to put your autoconfig devices inbetween the DMAC and where ever it's CFGOUT pin might lead in order to get Autoconfig working.

If you take CFGIN from the DMAC and put it into CFGIN of your A590, you'll end up with two Zorro II devices autoconfiguring themselves during the same turn -> conflicts and misery.

The Amiga Hardware Reference manual describes exactly how the autoconfig mechanism works, but in basic it's a chain of

motherboard -> CFGIN1
CFGOUT1 -> CFGIN2
CFGOUT2 -> CFGINX
CFGOUTX -> motherboard.

As many as you have Zorro boards (and of course making sure that they fit in the Autoconfig address space). Each autoconfig device gets to configure itself in turn and then it passes the turn over to the next one via the cfgout pin.

[*]XT-IDE is not in any way compatible with 16-bit AT-IDE drives, smoke will come out, do not attempt to connect modern drives there.

[Twanger]

Well, O.K.
Now, does anyone know how to put the A590 "between" the DMAC and the CD-Rom Controller? Unfortunately I´m not a developer and don´t know that much of the Hardware...

One more question to Jope:
" motherboard -> CFGIN1
CFGOUT1 -> CFGIN2
CFGOUT2 -> CFGINX
CFGOUTX -> motherboard"
Am I right that the last step "
CFGOUTX -> motherboard" is not required? A german developer told me that it´s not neccessary to connect the last autoconfigured device back to the CDTV (CFGOUTX - CFGINCDTV not necessary)!

Thanks,
Twanger

[Jope]

Ah, I can't remember 100% how it goes (you have the schematics!)..

Perhaps it ends in a terminating pullup resistor or something..

Basically, to put your device in the chain:

Originally Posted by Jope

Where does the cfgout pin go in the schematics? Is it tied high or low or what happens to it? (can't remember how it should go)

Check that, cut it if it goes somewhere and then connect the cfgin of your next zorro device to the dmac's cfgout and the next device's cfgout goes to where the DMAC's cfgout used to go.

I don't believe in leaving signals to float in the open, so if it is terminated somehow, you need to terminate it yourself too.

Also, if the DMAC's cfgout is terminated, you must remove that termination (cut the trace) and connect your device in between the dmac and the terminator.

[Twanger]

Originally Posted by Jope

Where does the cfgout pin go in the schematics? Is it tied high or low or what happens to it? (can't remember how it should go)

Check that, cut it if it goes somewhere and then connect the cfgin of your next zorro device to the dmac's cfgout and the next device's cfgout goes to where the DMAC's cfgout used to go.

Originally Posted by Twanger

The CFGOUT is connected to the diagnostic port (my schematics say that; I know others say that the CFGOUT is NOT connected...), and the CFGIN is also connected to the diagnostic port where it is finally grounded...

As far as I can see the CFGOUT goes nowhere else as to the Diagport (as I said before)!
That´s the poin what I meant before - so I don´t know where to put something in between - because putting the A590 between the CFGOUT won´t solve the problem because the CFGOUT only is connected to the Diagport...

[BinoX]

Originally Posted by doelen

So far, I've installed ECS and Kick3.1 + extended roms.

I can't find the kickstart ROM on my CDTV board... I'm probably blind but I can't find it.. can you tell me where it is?
(Already have ECS and extended roms installed)

[Twanger]

When the CDTV front faces you: neraly in the middle of the mainboard - a little bit more to the back of the CDTV; just behind two coloured connectors in th e middle of the mainboard

I've just removed the DMAC and ripped the socket off my spare, defect mainboard and come to the following conclusion:

Confirming Twanger that
DMAC 71 CONFIGOUT is only connected to Diagnostic 5
DMAC 72 CONFIGIN: The trace disappears behind the diagnostic connector, so I assume that it's connected to Diagnostic 6 as stated in other sources. It goes nowhere else.

The weird thing however:
Diagnostic pin 6 is grounded (confirming other sources) via a trace on the back of the mainboard
And also Diagnostic pin 5 IS ALSO GROUNDED via a direct trace to pin 1. Can someone confirm this with a multimeter or something ???

I can make a picture of the traces if someone is interested, but I'll have to wait for my girlfriend to come home with the digital camera.

So do we have to cut one of the traces that ground Diagnostic 5 or 6 to make this work ????

[Jope]

Trace the configin of the DMAC, it should go further.

[Twanger]

Originally Posted by Jope

Trace the configin of the DMAC, it should go further.

@Jope:
Thank´s for your help so far but why don´t you just tell us what you know that could help us?

@doelen:
My pinouts of the A500 expansion port say that the CFGOUT at the A500 is also grounded!? => heared that is called "LOW signal"?

Strange is that all the internet sources say that CFGOUT is not connected to pin 5 at all; but you and my CDTV schematics say it is connected...

Another source says that the solution could be to cut the connection between pin6 (CFGIN) and "ground". But I still think that the CFGIN is nor required at all!?

=> total confusion! Anyone can help us?

[Jope]

Originally Posted by Twanger

@Jope:
Thank´s for your help so far but why don´t you just tell us what you know that could help us?

Seriously, read my postings, they've got the information in them.

Also they have pointers to information (the Hardware book from the RKM set) if you really want to understand what is happening when Zorro devices autoconfigure themselves.

I don't really know how much clearer I can explain this:

- in Zorro(tm) Autoconfig(tm) the first device's config out signal goes to the next device's config in
- your DMAC chip is on the autoconfig chain, so it's config in must come from somewhere, because the autoconfig mechanism needs to be started somehow
- your new device gets it's config in from the DMAC's config out
- the DMAC's config out must be disconnected from it's present destination and be rerouted to your new device's config in
- your new device's config out must go to where-ever the DMAC's config out used to go

That's about what I have to offer on this..

After all, you have the schematics, you are the one who's doing the job.

I would have to read the schematics myself to tell you exactly what goes where, which I find rather pointless since you already have the information and you are the person who actually needs to know all this in order to do the hardware modification you're planning on. (I have never even owned a CDTV)

Thus you are the best person to read the schematics to learn what goes where, and then work with what you learn from there, and with the info I've rambled on about in this thread.

Please feel free to ask questions, but I'm afraid I can't provide you with a full solution to this unless I were to do it myself first and then tell you all the steps.. I can give you info on how the Amiga hardware itself works, you can then apply that information to the machine you have in your hands.