18 replies to this topic

[Ripper]

Hi i'm working on a project to turn on of my old Atari 520 STe 's into an mini - itx emulator machine to make it more useful since i have two of them anyway (I can offer any of the innards as i don't need them this particular one is unmodified.)

My main stumbling point at the minute is the power supply and the keyboard. the keyboard being the biggest issue as i'm aiming to convert it to either a ps2 or usb connection and to do either as far as i know i need another controller chip and was wondering whether you think one of these would do the trick ;

http://www.vetra.com/Encoder2.htm

and this model VIP-312-128 since if I've counted correctly theres 95 keys on the Atari st keyboard.

i know its not strictly Atari on the other hand has anyone seen a scsi cable that connects two Atari hard drives together as i have two one from each atari but can currently only connect one at a time due to the terminated connections.

thanks any advice idea's or if interested in the gutted parts feel free got tons of st floppy disks to go through and need to work out what i did with the old hand scanner for it

[mimo]

There was someone in the 8bit forums that used an aftermarket encoder to use his Atari 1200XL as a PC keyboard. Maybe you could have a search there for some info

[pepax]

You can also ask the guys from Individual Computers if they are planning to produce an Atari ST version of Keyrah. But I somehow doubt it.

[Bryan]

The way to do it would be to use a small $2 microcontroller. There are PS/2 keyboard routines out there for AVR, PIC and others, and then you'd just need code to scan the Atari keyboard. In other words, it's possible for someone willing to do the work.

[atariksi]

mimo, on Tue Dec 9, 2008 6:31 PM, said:

There was someone in the 8bit forums that used an aftermarket encoder to use his Atari 1200XL as a PC keyboard. Maybe you could have a search there for some info

I had one customer who purchased the Atari 800XL keyboard simulator cable to use in reverse (use 800XL keyboard on PC) hooked up via parallel port. Normally, it allows you to use PC keyboard to simulate Atari 1040 ST and Atari 8-bit keyboards. PC's parallel ports are bi-directional and so are Atari joystick ports so it works the other way around as well.

[Ripper]

a parallel solution wouldn't be beneficial as all i'm using is the original keyboard but it does offer one method for playing with my other ST , I've just contacted Individual Computers hopefully they'll reply.
i can code a little what sort of microcontroller would i need is it similar to that coin- op board i linked to in my original post? and i'm in the uk here and really glad to find theres life in the atari world. If you could link me to some plausible controllers i would be very grateful i've been looking for possible solutions for ages even changing the backing of the keyboard with an old usb one but some of the keys are different , so enevitably that failed.

After i've got this sorted its whether to modify the orignal atari power supply (depending on how powerful it is) or stripping a pc one.

Thanks for the help

[Ripper]

i still am unsure which pic chip to use and how to program them :S

[ijor]

I'm not quite sure I understand what you want. Do you want to use an ST keyboard (or computer) emulating a PS/2 and/or USB keyboard? Or you want to use a PS/2 and/or USB keyboard with the ST computer?

All of the possibilities are feasible, but none of them are trivial. If I understand correctly, you want the former (an ST keyboard, or computer) emulating a PS/2 or USB keyboard.

Emulating a PS/2 keyboard shouldn't be too difficult, but it changes a lot if you would be using the ST keyboard alone (which would require scanning the matrix), the ST keyboard interface (which would require understanting and parsing the ST IKBD interface), or just the whole computer.

Emulating an USB keyboard is a bit more difficult, but the main issue here is that you need a microcontroller with built-in USB device controller. There are plenty of those, but USB support is usually not present at the lower end of PIC or AVR lines.

Edited by ijor, Wed Jan 7, 2009 1:31 PM.

[poobah]

ijor, on Wed Jan 7, 2009 2:29 PM, said:

Emulating an USB keyboard is a bit more difficult, but the main issue here is that you need a microcontroller with built-in USB device controller. There are plenty of those, but USB support is usually not present at the lower end of PIC or AVR lines.

You can bit bang low speed HID devices with the AVRs, right down to the Tiny2313 no USB controller needed.

[ijor]

poobah, on Wed Jan 7, 2009 7:35 PM, said:

You can bit bang low speed HID devices with the AVRs, right down to the Tiny2313 no USB controller needed.

So you recommend him to save a few dollars and bit-bang USB instead of using a proper USB controller? And then add the diferential transceiver that might cost him even more ? Or again, not using a proper differential interface just for saving a few dollars?

A quick trip to Atmel's and Microchip's websites show that MCUs with integrated USB start at ... around U$3 on single quantities! Do you think it is worth to bit-bang?

Honestly, they are cheaper than what I thought when I wrote the previous post. And I forgot about those widely available, PS2/USB converters that lately cost a couple of dollars; which is another option.

[poobah]

ijor, on Wed Jan 7, 2009 7:54 PM, said:

poobah, on Wed Jan 7, 2009 7:35 PM, said:

You can bit bang low speed HID devices with the AVRs, right down to the Tiny2313 no USB controller needed.

So you recommend him to save a few dollars and bit-bang USB instead of using a proper USB controller?

Nope.
You said:

Quote

The main issue here is that you need a microcontroller with built-in USB device controller

That is clearly incorrect. No recommendation, just an observation.

[ppera]

I think that discussion went to less relevant things. What microcontroller costs couple bucks less is really not so important. Here is biggest problem programming of adapter. I don't think that existing libraries are of much use. Maybe, but kbd. matrix of Atari is certainly not same as in PC keyboards.

"Honestly, they are cheaper than what I thought when I wrote the previous post. And I forgot about those widely available, PS2/USB converters that lately cost a couple of dollars; which is another option."

Such converters are usually (those cheap ones for sure) just passive connector adapters. As most of mouses with USB connectors use PS2 protocol. It is checked - myself made PS2-Atari adapter, and it works well with all of 4 my USB mouses.
I think that only special gamer mouses use real USB protocol to have faster response, as PS2 protocol is not suitable for fast action games due to slow transfers.

[Ripper]

ijor, on Wed Jan 7, 2009 7:29 PM, said:

I'm not quite sure I understand what you want. Do you want to use an ST keyboard (or computer) emulating a PS/2 and/or USB keyboard? Or you want to use a PS/2 and/or USB keyboard with the ST computer?

All of the possibilities are feasible, but none of them are trivial. If I understand correctly, you want the former (an ST keyboard, or computer) emulating a PS/2 or USB keyboard.

Emulating a PS/2 keyboard shouldn't be too difficult, but it changes a lot if you would be using the ST keyboard alone (which would require scanning the matrix), the ST keyboard interface (which would require understanting and parsing the ST IKBD interface), or just the whole computer.

Emulating an USB keyboard is a bit more difficult, but the main issue here is that you need a microcontroller with built-in USB device controller. There are plenty of those, but USB support is usually not present at the lower end of PIC or AVR lines.

i'm converting an st to an atom based computer the only snag i have is that i want to keep the original keyboard and functionality so all i'm keeping is the keyboard so usb would be ideal...but ps2 i can cope with too.

[ijor]

ppera, on Thu Jan 8, 2009 8:58 AM, said:

Such converters are usually (those cheap ones for sure) just passive connector adapters. As most of mouses with USB connectors use PS2 protocol. It is checked - myself made PS2-Atari adapter, and it works well with all of 4 my USB mouses.

I think you are talking about converters in the reverse direction. I meant those converters that let you use an old PS/2 keyboard with say, a modern laptop without PS/2 ports. I never used one, but I doubt very much those are just passive connectors. They do cost a bit more than the ones you are talking about.

The idea is that in case he doesn't want to program/build an USB device, he can make a (presumably) simpler PS/2 one, but yet use it as USB with one of those converters.

[ijor]

Ripper, on Thu Jan 8, 2009 10:34 AM, said:

i'm converting an st to an atom based computer the only snag i have is that i want to keep the original keyboard and functionality so all i'm keeping is the keyboard so usb would be ideal...but ps2 i can cope with too.

I see. Again, you can make this at two different levels. The ST keyboard (as all PC keyboards, even the oldest ones) has its own microcontroller. You can hook your ps/2 or USB device before the mcu (and discard it, if you want), or after it.

Each approach has its pros and cons, might be just a matter of personal preference. If you discard the keyboard micro, then you must perform the physical process of scanning the matrix. If instead you keep it, then your design just interfaces with it using the Atari published IKBD protocol (similar in many aspects to the PC keyboard protocol). The connection is simple standard serial async.

It shouldn't change too much in terms of which microcontroller you should use, except perhaps that you need more I/O pins for scanning the matrix. At first glance, keeping the keyboard microcontroller sounds a better idea.

Regarding exactly which micro to use. Personally, I wouldn't worry too much. You are not going to sell this product (I understand). So you probably don't care too much if the micro costs $5 or $20. What I'm trying to say is that it might be wise to use an overkill device (more flash, more ram, some pins to spair, faster speed, etc). Just make sure it comes with DIP encapsulation (unless you feel confortable with other ones). And I'd get one that has hardware support for PS/2 and/or USB.

Depending on your budget and microcontroller experience, you might prefer to get one of those starter kit development boards.

Edited by ijor, Thu Jan 8, 2009 9:41 AM.

[ppera]

ijor, on Thu Jan 8, 2009 4:19 PM, said:

...
I think you are talking about converters in the reverse direction. I meant those converters that let you use an old PS/2 keyboard with say, a modern laptop without PS/2 ports. I never used one, but I doubt very much those are just passive connectors. They do cost a bit more than the ones you are talking about.
...

Sorry, but you talked about "lately cost a couple of dollars". PS/2-USB converters are over 20 Euros usually.

[Ripper]

any recomendations on these microcontroller starter kits? i'm i'm deffinitly new to this sort of stuff but i'll do what ever it takes to complete this project. keeping the atari controller deffinitly seems the way sofar is that the big black chip on the underside of the keyboard?

[magic_gun]

hi,
biggest obstacle for this job our old friends are not compatible with keyboard ps 2
There are 2 ways to solve it I think .....

ST flour standard ps2 keyboard layout, and in the matrix will be adapted to the keyboard controller on the 6801 mc cancel and saw out on the ps2 chip mounted to the keyboard pcb ...

to the line without touching any of the original keyboard output signals of a mc 6801 to convert to a pc what is in the format it understands the same and only the ascii code sequence and frequency are different instructions, and both serial

patience and attention and in this process pretty empty time and wants mc knowlage
some keys are missing , but not much difference in general use


Thanks for everything
come in for more details

[magic_gun]

hi
keyboard conversion problem
We have solved for each retro Computer
like atari st ,xl and amiga
and 2 piece 9 pin quickshot joysitick support for pc






http://www.atariturk...-transform.html