PS/2 keyboard and mouse to Archimedes adapter

[IanB]

I've designed an adapter to connect a PS/2 keyboard and mouse to an Archimedes or A5000 etc., mainly so I can use these machines via a KVM switchbox from the same console as the rest of my computers.

Construction is very simple as it uses just a PIC 16F88, a crystal and a couple of capacitors together with some PS/2 extension leads cut in half so I ended up building it directly on a turned pin socket without any circuit board.

I've got the mouse and keyboard protocol translation software working, but I'm currently looking at the best way of handling the various incompatabilities between the PS/2 keyboard and Acorn layouts, like the caps lock/ctrl and double quote/@ swap. I think the best solution is to have two modes, a game mode with keys physically matching the Acorn layout as close as possible and a normal mode where the keys actually correspond with their legends. Modes could be switched using the windows keys on the PS/2 keyboard which have no function on an Archimedes.

Here's a pic of the adapter although it's not much to look at:

ps2cable.JPG (58.55 KiB) Viewed 1727 times

When it's finished, I'll post the code here but if anyone would like to do any beta testing, please let me know (You'll need a PIC programmer!)

Ian

[IanS]

Awesome.

It would be good to see a pcb with a couple of ps/2 sockets on it made up. I suspect you'd get a lot of interest if you started selling them.

[TopBanana]

Fab

Circuit boards for numpties like me would be great

[riscknight]

Looks very promising.

Well Done.

[danielj]

Looks ace. I'm happy to test the mouse-part of it?

d.

[TheCorfiot]

Superb
My RPC would love one of these.

TC

[1024MAK]

Looks interesting and useful

I do like the idea of reducing the number of keyboards, as I find that I often type away on the wrong one

If the circuit is not complex, a piece of strip-board would do... (with the same arrangement of using PS/2 extension leads cut in half).

I can program PIC chips (and I think I have a spare PIC 16F88) so if you want me to do any beta testing, or strip-board layouts, let me know.

Mark

[IanB]

I can program PIC chips (and I think I have a spare PIC 16F88) so if you want me to do any beta testing, or strip-board layouts, let me know.

I don't seem to be able to send PMs (probably not enough posts) but it looks like I can receive them so if you send me a PM with your email address, I'll send you the details.

Looks ace. I'm happy to test the mouse-part of it?

If you mean you want to use a PS/2 mouse with an Archimedes keyboard, this adapter won't do that, you need a PS/2 to quadrature adapter and I think there are a few commercial solutions available as well as a DIY version by someone else although that version has some issues with KVMs so I may do my own DIY version of that when this adapter is finished.

My RPC would love one of these.

Risc PCs already use a PS/2 keyboard and if you mean the mouse, you need the quadrature adapter mentioned above.

It would be good to see a pcb with a couple of ps/2 sockets on it made up.

I've not investigated low volume pcb production before, so does anyone have any pointers?

Ian

[paulv]

I'd be interested in a few of these for my A5000, A410/1 and A310. I don't have PIC programming capability though so I'd need to buy some pre-programmed I guess

I know Jon Abbott has a similar project on the back burner at the mo whilst he's working on ADFFS for the Arc's too. It may be worth having a chat with him about it too.

Paul

[steve3000]

Interesting project indeed...!

I've got the mouse and keyboard protocol translation software working, but I'm currently looking at the best way of handling the various incompatabilities between the PS/2 keyboard and Acorn layouts, like the caps lock/ctrl and double quote/@ swap.

How was this handled on the RiscPC? That uses a PS/2 keyboard... or was it not handled at all (tbh I never played that many games on the RiscPC).

[jms2]

I'm not sure it was handled at all - doesn't cause any real problem in practice.

[hoglet]

Hi Ian,

This looks like a very handy project indeed!

Would you be willing to post the PIC assembler source so I could have a go at building one?

I'd just made a spur of the moment purchase on ebay, and I doubt it will be coming with a keyboard or mouse:
http://www.ebay.co.uk/itm/Acorn-Compute ... 0679431846

Thanks

Dave

[sirbod]

I know Jon Abbott has a similar project on the back burner at the mo whilst he's working on ADFFS for the Arc's too. It may be worth having a chat with him about it too.

I have indeed, have all the chips, programming gear, sockets, cable etc. just not the time to design and code the PIC code.

I have a working mouse adapter using a 16F84 (for RiscPC) and went for an Atmel 89C4051 for the combined mouse/keyboard (for Arcs) as its close to the embedded CPU in the Arc keyboard.

Annoying the Eagle software had the pinout of the 9 pin din incorrect, so I had to redesign the mouse only board, I've yet to etch and retest, but am planning on doing so in the next few months.

I think I part designed the board for the combined one, based on the Arc schematics, but haven't touched it for over a year. I'd dearly love to chuck all these pesky mice that are littering my test area!

Ian, drop me an email I'm happy to test: jon@jaspp.org.uk

[JonC]

Sorry for the Necro post.

Is there a board layout/part list for this as I'd like to make a couple?

Cheers

Jon

[IanB]

Sorry for the Necro post.
Is there a board layout/part list for this as I'd like to make a couple?

I made a followup post with construction details using an off the shelf prototyping PCB here:

viewtopic.php?f=16&t=9334&p=107743

[JonC]

Sorry for the Necro post.
Is there a board layout/part list for this as I'd like to make a couple?

I made a followup post with construction details using an off the shelf prototyping PCB here:

viewtopic.php?f=16&t=9334&p=107743

Cheers Ian, that one didn't come up on my searches for some reason.

[munchausen]

Looks ace. I'm happy to test the mouse-part of it?

If you mean you want to use a PS/2 mouse with an Archimedes keyboard, this adapter won't do that, you need a PS/2 to quadrature adapter and I think there are a few commercial solutions available as well as a DIY version by someone else although that version has some issues with KVMs so I may do my own DIY version of that when this adapter is finished.

Sorry for the necro-post, but this sounds like it is converting PS/2 mouse to quadrature (as well as PS/2 keyboard to arc). I must be misunderstanding something? Does the A5000 not use quadrature mice?

[IanB]

Sorry for the necro-post, but this sounds like it is converting PS/2 mouse to quadrature (as well as PS/2 keyboard to arc). I must be misunderstanding something? Does the A5000 not use quadrature mice?

The Archimedes / A5000 etc keyboard has a socket for a quadrature mouse but decodes the quadrature signals in the keyboard itself and outputs a combined serial data stream containing info on keys pressed and mouse movements so the Arc never sees the quadrature signals. The converter takes a PS/2 keyboard and PS/2 mouse in and ouputs the same serial data stream as the Arc keyboard so there are no quadrature signals.

[poink]

The Archimedes / A5000 etc keyboard has a socket for a quadrature mouse but decodes the quadrature signals in the keyboard itself and outputs a combined serial data stream containing info on keys pressed and mouse movements so the Arc never sees the quadrature signals.

Incidentally, it should be usable on any of the Archimedes machines - all of the VIDC systems; including the A30x0 and A4000, use the same system due to the keyboard interface (KART) being implemented in the IOC. The ones that have an integrated keyboard simply place the the microprocessor (87C51) that would be in a detachable keyboard on the motherboard.

[munchausen]

Sorry for the necro-post, but this sounds like it is converting PS/2 mouse to quadrature (as well as PS/2 keyboard to arc). I must be misunderstanding something? Does the A5000 not use quadrature mice?

The Archimedes / A5000 etc keyboard has a socket for a quadrature mouse but decodes the quadrature signals in the keyboard itself and outputs a combined serial data stream containing info on keys pressed and mouse movements so the Arc never sees the quadrature signals. The converter takes a PS/2 keyboard and PS/2 mouse in and ouputs the same serial data stream as the Arc keyboard so there are no quadrature signals.

Aha - makes sense

So now I have another question!

On the A3010 (and A3020 I'm guessing) there is a socket on the motherboard for a "normal" acorn keyboard (that isn't routed to the back of the machine). If that's the same (albeit with a different pinout) as the A5000 and so on, presumably you could plug your adapter into it? (and even replace the acorn mouse socket at the rear of the machine with a combined PS/2 keyboard/mouse socket).

[poink]

(and even replace the acorn mouse socket at the rear of the machine with a combined PS/2 keyboard/mouse socket).

With judicious track cutting, you could actually do this on any of the Arcs - the standard Arc keyboard connector is the same as the PS/2 connector (and, fortunately, for people who try PS/2 devices, the power is on the same pins!). As there's a standard(-ish) layout for a combining keyboard and mouse in one PS/2 connector, it could work out very well on the Arcs.

[IanB]

On the A3010 (and A3020 I'm guessing) there is a socket on the motherboard for a "normal" acorn keyboard (that isn't routed to the back of the machine). If that's the same (albeit with a different pinout) as the A5000 and so on, presumably you could plug your adapter into it? .

Yes the adaptor should work on all Acorn RISCOS machines apart from the RISC PC and A7000/+. On systems like the A3010 with a built in keyboard you will have to change a link on the motherboard to switch from the internal keyboard to the socket.