My new little project - CD32 Expansion Slot (prototype)

[Amiga1992]

Originally Posted by th4t1guy

The sx1 would not be able to work with this, as it wouldn't fit inside the cd32, but it has RGB anyways.

Sorry, I didn't think you meant to use with this.

There is nothing to use with these yet But I hope soon there will be!

And about RAM, I guess if you put a full 68020 in there, Fast RAM capacity might get larger (and I am hoping compatibility would be the same with an EC020?).

[th4t1guy]

Well, the FMV module should work, and possibly the sx32 might partially work, but yes, I would love to see new expansions for the cd32 as well!

I got the info about the RAM limits here: http://amiga.resource.cx/mod/cd32.html

You can run a lot with 10mb of RAM, but Workbench could be a little better with some more. I've run ClassicWB 3.1 and default 3.9 on the cd32, and both are very usable at 16 colors. However, it often feel likes 10mb is right on the edge.

[patrik]

Originally Posted by plasmab

I did not know that. Useless though because I'll have a keyboard plugged in there.

I bought some PS/2 Y-adapters/splitters made for laptops, used to connect both mouse and keyboard to a single PS/2 connector on the laptop. These forward the keyboard signals to one connector and the two unused PS2 pins to the other. As the amiga uses the same pins as PS/2 for the keyboard, and the two unused pins are /TXD and /RXD on the CD32, this is perfect. Both female connectors have GND and +5V.

So just chopped of the female PS2 connector connected to the serial pins and connected a DB9 TTL<->RS232 converter there.

Unfortunately, I have no idea if I was just lucky with my purchase, or if this is a the most common PS/2 Y-adapter/splitter pinout.

Attaching an image of how it looks like this when connected to a null modem cable and an A2000 keyboard.

[E-Penguin]

Did you have to invert the TTL serial lines for the RS232 converter, or are you passing them through as-is?

I want to make a SLIP wifi adapter for the CD32, or at least interface it to an existing one.

[patrik]

Originally Posted by E-Penguin

Did you have to invert the TTL serial lines for the RS232 converter, or are you passing them through as-is?

No, they are the correct the way they are already. I have also read that misinformation which unfortunately is circulating. They aren’t inverted in other amigas before the TTL<->RS232 converter btw, just check the schematics.

Works in 115200 in NComm with 8n1.device btw, but I wouldn’t count on it if the system is loaded with other things at the same time.

[E-Penguin]

That's interesting - I've read in several places about the TTL inversion. I'll have to get out my arduino and start probing...

[patrik]

I guess it’s a case of someone saying something they thought was correct, without verifying it, which unfortunately happened to be spread further and became “the truth”.

The CD32 Debug Board Schematics should be a good source for example, it passes /RXD and /TXD directly to a MAX241.

Also, I am quite sure there is no chance it would work at 115200 if the signal was inversed compared to what it should be.

[E-Penguin]

Could it be the rs232 converter is triggering on the rising edge at the end of the bit, effectively performing the inversion by default? If you're only counting rising edges then both logics are equivalent.

The schematics do show it as being inverted on the connector.

[patrik]

Yes, all the RS232-converters I have seen are shown as inverters in their internal schematics - just check the data sheet for say the classic MAX232. It is probably no coincidence that /RXD and /TXD are active low on Paula already.