Amiga questions you've always been too embarrassed to ask

[Toni Wilen]

Originally Posted by Gilbert

Not embarrassed to ask this but can the Amiga CD32 stream in data from CD while it's playing games - using the Akiko chip?

There is one more problem that was not yet mentioned: CD32 CD drive is stupid and can't DMA CD data directly to final address. CD32 works this way:
- Akiko DMAs data to temporary CD buffer
- Handle low level CD error correction using CPU (yes, CPU needs to do it, hardware can't do it!)
- if 2048 byte sectors needed: extract 2048 byte sector from raw data and do even more error correction stuff.
- Copy "cooked" data to final address.

Which wastes CPU time.

CDTV can do all steps without CPU help..

[Foebane]

I heard they sacrificed AAA development to focus on the CD32, right? Typical.

In fact, since so many CD-ROM platforms failed, I'm starting to think that Sega and Commodore were seduced by the Deadly CD Pitcher Plant of Doom. Only Sony escaped unscathed.

[Gilbert]

Thanks for all the info about cd streaming on CD32

Originally Posted by Toni Wilen

There is one more problem that was not yet mentioned: CD32 CD drive is stupid and can't DMA CD data directly to final address. CD32 works this way:
- Akiko DMAs data to temporary CD buffer
- Handle low level CD error correction using CPU (yes, CPU needs to do it, hardware can't do it!)
- if 2048 byte sectors needed: extract 2048 byte sector from raw data and do even more error correction stuff.
- Copy "cooked" data to final address.

Which wastes CPU time.

CDTV can do all steps without CPU help..

Wow Commodore really didn't know much about games programming, after the original team left.

But it can still do it? Even if it uses the CPU - because the CPU in the CD32 is pretty powerful compared to say a Neo Geo or Megadrive.

Because I remember SWIV on A500 streamed from floppy drive. I imagine that used CPU too?

[Akiko]

Did Amiga ever have proper Dual channel ISDN support @ 128kbit/s?

I recall some of the hardware vendors back then claiming they were working on supporting it, but did any of them successfully implement it?

[NLS]

I don't think this has anything to do with Amiga, except maybe the speed of the serial port (if it can go high enough).

An ISDN TA capable of handling two channels with proper AT commands, will connect to a destination also capable of handling two channels.
Then it is just a matter of the Amiga being able to (buffer) handle the speed of 128kb up/128kb down.

If you ask if there was card or something directly connecting ISDN bus to the Amiga, not so sure.

[McTrinsic]

Wasn’t the ISDN Master able to do that?

[trixster]

Originally Posted by Gilbert

But it can still do it? Even if it uses the CPU - because the CPU in the CD32 is pretty powerful compared to say a Neo Geo or Megadrive.

What gives you that idea?

[d4rk3lf]

Ok, following my A500 max (proc) upgrades, I'd like to ask some further questions:

1) Before RTG. Is there any option to upgrate your OCS/ECS systems to something like AGA? And, is there any old card (from nineties) that give RTG to OCS/ECS?

2) What about Amiga 1000? Can it be 060 somehow? How much chip and fast ram will A1000 motherboard handle? I've heard that Aca 500+ is working fine with A1000. Is that mean we can still pull a Blizz 060 card in it, and it will work?

3) What about CDTV (I don't know why, I never seen one in real life, but I got really fond with it)? Can we make that nice machine RTG, AGA, or 060, or something? What's the best upgrades out there?

[DamienD]

Originally Posted by d4rk3lf

3) What about CDTV (I don't know why, I never seen one in real life, but I got really fond with it)?

My one and only real Amiga was an A500 with 512KB expansion, that my stepfather purchased used from one of his friends.

5 years later at the age of 17, I'd left home and moved in with this guy as he had a spare room and it was in the same suburb where my work was.

He had an Amiga CDTV, so I used to mess around on it

[jotd]

Lesson 1: choose your roommates.

[Fastdruid]

Originally Posted by McTrinsic

Wasn’t the ISDN Master able to do that?

Think that was 2*64
http://amiga.resource.cx/exp/isdnblaster

[StevenJGore]

Originally Posted by TroyWilkins

That does make me wonder, is that the way the "video" shown in the main window of the CD32 game "Microcosm" was loaded? Does anyone know? That would have made sense, as that could be streamed without the seek times or data rate being an issue?

Originally Posted by Gilbert

But it can still do it? Even if it uses the CPU - because the CPU in the CD32 is pretty powerful compared to say a Neo Geo or Megadrive.

I remember reading at the time of release (would have been in Amiga Format or Amiga CD! Magazine) that Microcosm streams data from the CD for the tunnel backgrounds

[Fastdruid]

Originally Posted by d4rk3lf

Ok, following my A500 max (proc) upgrades, I'd like to ask some further questions:

1) Before RTG. Is there any option to upgrate your OCS/ECS systems to something like AGA? And, is there any old card (from nineties) that give RTG to OCS/ECS?

I think just about anything Zorro II can be fitted to an A500/A1000, which means that for example you could fit one of the pre-AGA Zorro-II cards, eg http://amiga.resource.cx/exp/a2410

The MNT VA2000 would probably work as well.

Originally Posted by d4rk3lf

2) What about Amiga 1000? Can it be 060 somehow?

Absolutely, if you can fit one to the A500 you can fit it to the A1000. Although there are some issues (eg around the roms) these can be overcome.

Originally Posted by d4rk3lf

How much chip and fast ram will A1000 motherboard handle?

8Mb fast ram same as all the others.
1Mb Chip ram, although need 3rd party stuff to do it.
You can fit more fast ram to processor cards if they have a full 32bit processor on.

Originally Posted by d4rk3lf

I've heard that Aca 500+ is working fine with A1000. Is that mean we can still pull a Blizz 060 card in it, and it will work?

Yes, the slot on the A1000 is the same (well 98%) as the A500/A2000a (and 94% the same as the co-processor slot in the A2000b) and the changes don't really make any difference. So yes it'd work.

Originally Posted by d4rk3lf

3) What about CDTV (I don't know why, I never seen one in real life, but I got really fond with it)? Can we make that nice machine RTG, AGA, or 060, or something? What's the best upgrades out there?

Ah, AIUI that's a no. I mean you _can_ but then it doesn't work as a CDTV anymore. It is apparently very hard to upgrade beyond some extra memory or "official" expansions.

[McTrinsic]

Originally Posted by Fastdruid

Think that was 2*64
http://amiga.resource.cx/exp/isdnblaster

Sorry I meant the ISDNSurfer.

https://amiga.resource.cx/exp/isdnsurfer

Don’t know if the respective driver was actually released.

[d4rk3lf]

@Fastdruid
Tnx bro.

[wiz12]

Is there any difference between 391078-01 & 391078-02 CIAs?

[sneeker]

Im still friends of sort with a guy who ran a bbs here in the uk, he could channel bond on his a1200 then A4000 so he had the full 128kb/s from his isdn, and he had a usr courier running the bbs side at the same time, probably using a surf squirrel or similar on the 1200.

[Fastdruid]

Originally Posted by wiz12

Is there any difference between 391078-01 & 391078-02 CIAs?

Yes. According to this: https://www.amiga-stuff.com/hardware/8520.html

They're surface mount CIA's.

391078-01 is a CIA which runs at 1MHz
291078-02 is a CIA which runs at 2MHz

Functionally however apart from the speed they are identical.

[Daedalus]

Despite the speed rating difference, they're both run at the same speed in Amiga terms so the performance won't differ. I have a vague recollection of one having a slight bug that wasn't present in the other - something to do with I/O latching or something? Anyway, in general use there's no practical difference between them.

[wiz12]

That seems kind of strange the way Commodore would have two identical parts but just a 1Mhz speed difference between them, could it be that the 02 model has these bug fixes?