Amiga and Raspberry pi

[kolla]

For some time I have been using Raspberry Pis (regular and zero) together with my Amiga systems. A few weeks ago, I installed one inside my A3000, and lately I have been pondering, if perhaps there are better ways to connect them.

Why and how am I using raspberry pi together with Amiga?

Amiga is lacking a lot when it comes to modern networking, by putting a system between the Amiga and the internet, many of these shortcoming can be circumvented, and the pi is quite perfect, since it is cheap and well supported.

* use ethernet between Amiga and Pi, Pi being NAT server for the Amiga
* the Pi can connect to any modern wifi networks, and IPv6, unlike Amiga
* use Pi as proxy for web (and ftp), let the proxy deal with "heavy" https
* Pi as "jump-host" for remote shell, use telnet and rsh to pi, and ssh from there
* mount Google drive, Egnyte, Box, whatever on the pi, and re-export to Amiga using protocols well supported on Amiga, like SMB or NFS.
* mount USB storage drives with filesystems not supported on Amiga, and export them to the Amiga
* There is something called "USB-over-Ethernet", with a proper driver for Poseidon, the USB ports on the Pi could be accessed from the Amiga.
* connect serial console on the Pi to a serial port on Amiga to have console access (null-modem)
* bonus possibility, Pi has HDMI and audio, so it's fairly easy to remote control the Pi to play media files or streams

So, what I am thinking about, for the A3000 (well, any Zorro system) is...

* a tiny Zorro board with a 40 pin connector for the GPIO pins on the Pi
* the Pi powered on GPIO pins by 5V from the Zorro bus
* UART + MAX3232 to connected to the TTL serial pins on the Pi
* ethernet interface each for both Amiga and the Pi, connected to each other

I have found some old projects for UART serial ports on Zorro, like for example http://aminet.net/package/docs/hard/icy - but tips are most welcome. The trickiest part is no doubt the ethernet part, and it may very well be redundant, as I already have ethernet on the A3000, and there are plenty of ethernet options for Pi already. Still, it would be cool to just have this one card and a pi, and not need anything else to go online

Thoughts? Tips?

[Jope]

Interesting! How about a plip driver via gpio?

[kolla]

Originally Posted by Jope

Interesting! How about a plip driver via gpio?

Maybe a possibility

Would also be neat if one could plug a Pi zero to the parallel port, like a Plipbox.

[Daedalus]

If you're just connecting the serial on the Zorro card to the Pi, you shouldn't need any level shifting at all if you pick a UART with TTL levels (which is most of them these days). That serial connection would also be capable of going much faster than the old Amiga serial of 115,200 baud, so you should be able to get reasonable transfer rates across it. You could maybe even go for a newer standard like I2C. Sounds like most of the work will be on the software side, which opens up a huge range of possibilities for increasing its functionality later on. Awesome stuff!

[kolla]

Originally Posted by Daedalus

If you're just connecting the serial on the Zorro card to the Pi, you shouldn't need any level shifting at all if you pick a UART with TTL levels (which is most of them these days).

Well, the Pi TTL uses 3.3V and the Amiga 5V, so I guess something must be done, so the Amiga doesn't fry the Pi

That serial connection would also be capable of going much faster than the old Amiga serial of 115,200 baud, so you should be able to get reasonable transfer rates across it. You could maybe even go for a newer standard like I2C.

Yes, I2C has come up again and again, I guess I must read more about it.

Sounds like most of the work will be on the software side, which opens up a huge range of possibilities for increasing its functionality later on. Awesome stuff!

Right, that's what I am thinking as well

As I mentioned, there is already this...

http://www.bigbookofamigahardware.co...ct.aspx?id=836

just need to hook it up with a Pi and write some drivers, huh?


This reminds me of the old HiQ Siamese project, except with Pi it is so much cheaper.
http://amiga.resource.cx/exp/siamese

[EugeneNine]

I've wondered the same for a while. 3.3v to 4v level shifters are not hard s thats now a big deal.

I'm wondering how did the bridgeboards work, when you put in a bridgeboard and get it running inside a window in an Amiga, is the video being captured or is the bridgeboard video writing to a chunk of ram the amiga can read? The control from the amiga to bridgeboard is that simply a register for keybaord characters? If the Amiga 'talks' to the bridgeboard just dumping characters into a memory location its easy enough to read the bus and read from that location.

[nogginthenog]

I wonder of one of those 2.5 inch HD PCI mounting brackets could be used to mount a PI in a slot?

It would be amazing if a proper Zorro card could be made that interfaces with a PI.

[kolla]

A good starting point will be just a board with zorro edge connector and a fairly large 2.54 mm pitch grid

EDIT: Well, turns out the Zorro slot itself (like ISA the slot) is also 2.54 mm pitch, so I guess just a cheap grid board will do.

[EugeneNine]

Yes, its a standard .1" spacing card edge connector used everywhere from zorro to ISA so C64/atari cartridge port to S100 bus, etc
You can buy those or download the part for kicad and create a whole card from scratch if you want.

[Daedalus]

Originally Posted by kolla

Well, the Pi TTL uses 3.3V and the Amiga 5V, so I guess something must be done, so the Amiga doesn't fry the Pi

Ah, indeed. I was more thinking about not needing RS-232 voltages (~ +/-10V), but if it uses 3.3V serial that's gonna need shifting too. I did think it used 5V though for serial, but my memory must've let me down.

As I mentioned, there is already this...

http://www.bigbookofamigahardware.co...ct.aspx?id=836

just need to hook it up with a Pi and write some drivers, huh?

Yep, as "easy" as that

[EugeneNine]

So if your talking about connecting a Pi to the Amiga by rs232 serial then the Amiga does indeed uses +/-12v. the pi does have a serial port so you can build an adapter to connect it like here http://elinux.org/RPi_Serial_Connection

Thats one method, your simply using the Pi as if you were 'dialing' into a BBS, run a gopher server or something on it to translate HTML to something a terminal program can use on the Amiga. You wouldn't need to connect to any Zorro slots for that, your essentially connecting the Amiga to the Pi via null modem. powering the Pi from the Amiga would be easier to just connect to 5v from a power supply connection than zorro slot.

remember the Amiga already has an internal serial connector though its the same as the external so you only have one port, just two connectors. A nice way to do it would be to make a zorro slot card with an additional serial port so you could dedicate that to the Pi and still keep the external port. IIRC there was some documentation on adding more ports either in the transactor or one of the fred fish disks as I remember adding more ports to be one of my projects I was going to do back in the day.

I thought when the OP said connecting the Pi GPIO to zorro slots they wanted something a little more integrated, there you would need 5v to 3.3v conversion.

[Amiga1992]

Originally Posted by EugeneNine

You wouldn't need to connect to any Zorro slots for that, your essentially connecting the Amiga to the Pi via null modem.
[...]
remember the Amiga already has an internal serial connector though its the same as the external so you only have one port, just two connectors.

I believe Kolla is trying to avoid the CPU overhead of using the serial port, as he explained to me in another thread, so connecting through serial would not be ideal.

[kolla]

Originally Posted by EugeneNine

You wouldn't need to connect to any Zorro slots for that, your essentially connecting the Amiga to the Pi via null modem. powering the Pi from the Amiga would be easier to just connect to 5v from a power supply connection than zorro slot.

I already do this, and more, I thought that much was obvious

[kolla]

Originally Posted by Akira

I believe Kolla is trying to avoid the CPU overhead of using the serial port, as he explained to me in another thread, so connecting through serial would not be ideal.

Yes, the internal serial port is better avoided.

[EugeneNine]

Thats what I thought until the discussion turned to RS232 voltages.

[pandy71]

IMHO Compute Module may be considered as versatile extension (coprocessor, graphic board, intelligent I/O etc). IMHO there is a sense to make Zorro board with interface to Amiga with CM RPi.
https://www.raspberrypi.org/products/compute-module-3/
With such approach DMA (CPLD/FPGA) can be used to fully link RPi with Amiga (perhaps even replace CPU by ARM emulation).
Practically 1 or 2 SPI on RPi would have sufficient bandwidth to fully saturate Amiga RAM bandwidth - Simple interface between SPI and Amiga should be more than suffcient for I/O.

[kolla]

@pandy71

Yup, sounds great, go right ahead

As I wrote earlier, my needs are more mundane, mostly about bypassing problems Amiga is facing in terms of networking and connectivity, protocols and software. For that, the "normal" pi, or pi zero, is a better option.

[pandy71]

No need to be sarcastic - RPi can also run browser and provide pre-rendered screens (perhaps even as plain CHIP RAM to be displayed almost without using 68k) - running web browser on 1GB RAM and 4MB RAM seem to be different story (don't even mention about video decoding in HW on RPi).
SPI on RPi and or 8520 SPI interface (slow and CPU hungry) or floppy port (500kbps with DMA). Clockport alternatively (small CPLD or perhaps few TTL's) to interface RPi's SPI with Amiga. Amiga serial port can be accelerated by Copper on Tx but receiving...

[Locutus]

Originally Posted by pandy71

browser and provide pre-rendered screens (perhaps even as plain CHIP RAM to be displayed almost without using 68k)

Yes this works and already exists: https://github.com/tenox7/wrp

Its a absurd way to do it but it actually works quite well on say iBrowse + 060...... amusingly enough a CSPPC with WarpOS GIF datatype is actually useful for this! :-D

[kolla]

Originally Posted by pandy71

No need to be sarcastic

I didn't mean to be sarcastic, just that the compute module requires more work, while the other Pis are more available and have all the ports built in.

RPi can also run browser and provide pre-rendered screens (perhaps even as plain CHIP RAM to be displayed almost without using 68k) - running web browser on 1GB RAM and 4MB RAM seem to be different story (don't even mention about video decoding in HW on RPi).

Yes, as I mentioned, web proxy is one of the things I have played with, including wrp, using Qt webkit to render images more suitable for Amiga browsers. You can also use RDP and get a Pi desktop up in a window (or screen).

SPI on RPi and or 8520 SPI interface (slow and CPU hungry) or floppy port (500kbps with DMA). Clockport alternatively (small CPLD or perhaps few TTL's) to interface RPi's SPI with Amiga. Amiga serial port can be accelerated by Copper on Tx but receiving...

Would be great to use the floppy port.