Atari OS rom MUST be an Eprom? Or not?

[Marius]

Are there other compatible chips to use in Atari 8bit computer as a replacement of OS rom?

 

Now I have 4 OS-es in a 27512 chip.

In other Atari computers i have 2 OS-es in 27256 chip.

 

Sometimes I want an OS upgrade (in case of myide or other situations). My eproms are not so happy with the erasing procedure. It fails a lot...

 

So now I want to know: is there a solution? Is there a ready-to-buy flash-os solution? (Where? Price?)

 

Are there other pin-compatible chips that can be programmed and erased without UV?

 

Thanks!

Marius

[+Stephen]

Apologies if it is not what you are quite looking for, but I really love my AtariMax 32-in1 OS. Sadly it is not "in-circuit" programmable, but it does use flash chips (can be reprogrammed in one of his 8Mb carts or via standalone programmer). I get no kickbacks for suggesting this, just a happy customer.

[Rybags]

32in1 OS - you can take the chip out and flash it in an 8 Megabit AtariMax Flashcart.

Not sure if it is "supported" in any sort of way, but people have done it.

 

I believe candle's upcoming RAM/OS expansion will allow 4 OSes which can be user-flashed.

 

One thing I'd like to try - the old DIP EEPROMs that PCs used for the BIOS before they went PLCC ~ 1985-1998, although I doubt they're pin compatible and have to be flashed on a PC motherboard by other hardware that can supply the appropriate voltages.

[candle]

Gary is correct - ultimate hold 4 slots for OS'es and slot for basic too - all programmable from atari user side of things

 

eeproms Gary mentions are pin to pin compatible with standard OS pinout, but some work has to be done if You want to programm them inside Atari

not much of it - and not that complicated

[flashjazzcat]

I bought three SST 29EE010 EEPROMs from China: I find these EEPROMs have many applications, but they'd overhang the OS socket by two pins. In any case, they're much more convenient than EPROMs.

[+JAC!]

I have modifed my BibiMon to hold 32k OS RAM for two OSs (normal SRBAM, battery backup).

 

I use it to load the OS from disk when required.

 

http://www.abbuc.de/galerie/userJAC/rimg0218_5.html

[Marius]

Apologies if it is not what you are quite looking for, but I really love my AtariMax 32-in1 OS. Sadly it is not "in-circuit" programmable, but it does use flash chips (can be reprogrammed in one of his 8Mb carts or via standalone programmer). I get no kickbacks for suggesting this, just a happy customer.

 

I'm a happy user of several Atarimax products too. But... I really would like to be able to update the flash rom with the Atari itself. I tried to lift such a flash chips once, and it was broke. I don't have the tools. I don't have the skills I guess...

 

I saw the MyIDE Internal has a flash OS, which can be updated on the fly? Does it contain two os'es? I guess the atari must be up and running to be able to update it...

 

Interesting stuff ...

 

Marius

[Marius]

I have modifed my BibiMon to hold 32k OS RAM for two OSs (normal SRBAM, battery backup).

 

I use it to load the OS from disk when required.

 

http://www.abbuc.de/galerie/userJAC/rimg0218_5.html

 

So you can update the OS in your atari by loading it from disk into that SRAM chip?

 

Wow. How do I get such a Supermon like yours?

 

That is great!

Marius

[Marius]

I bought three SST 29EE010 EEPROMs from China: I find these EEPROMs have many applications, but they'd overhang the OS socket by two pins. In any case, they're much more convenient than EPROMs.

 

Tell me more...

 

Can I simply add them in my Atari? Same pinout?

How many OS-roms are they able to contain?

 

Easy to erase?

Easy to program with a 'normal' eprom programmer or do I need another equipment?

 

Very interesting! Any pictures?

Thanks

Marius

[+bob1200xl]

You can get EEPROMs that hold 32K (2 OS ROMs) and have 28 pins that match your Atari ROMs. The only problem is the Write Enable line (pin 27), which is jumpered to +5v in the Atari. You need to connect pin 27 to R/W in the Atari in order to be able to program your EEPROM. From a practical standpoint, you also need to provide an OS that will execute the programming code for the EEPROM - I would suggest that you boot with the stock OS ROM, move the EEPROM to $4000, and load the code from disk (needs a special program...). You can use the two BASIC control lines in the MMU to do the magical stuff, like moving the EEPROM to $4000 and enabling the OS ROM <== needs MMU change. You can also use the TV channel switch to do some selection - saves adding holes for switches.

 

Atmel EEPROMs have s/w protection for data - others may also.

 

You can use SRAM and a battery...

 

Bob

 

 

 

 

Are there other compatible chips to use in Atari 8bit computer as a replacement of OS rom?

 

Now I have 4 OS-es in a 27512 chip.

In other Atari computers i have 2 OS-es in 27256 chip.

 

Sometimes I want an OS upgrade (in case of myide or other situations). My eproms are not so happy with the erasing procedure. It fails a lot...

 

So now I want to know: is there a solution? Is there a ready-to-buy flash-os solution? (Where? Price?)

 

Are there other pin-compatible chips that can be programmed and erased without UV?

 

Thanks!

Marius

[Marius]

@bob1200xl

 

Ok but without the wish to be able to program within the Atari, I can use other pin compatible chips to hold my OS ROM?

 

A flash rom or a EEprom...

 

So I don't have to "change" the OS... just put it in such a chip and put it in my Atari, and there I go?

 

The idea of program it with the atari is another wish, but not necessary. My biggest problem is: I don't want to erase my eproms everytime with that UV thing... it fails too many times in my case. Perhaps my eproms are erased already too many times. Does anyone know what the max amount of erase cycles is of a standard 27128 eprom?

 

Greetz

Marius

[+bob1200xl]

You need to use a quality eraser for EPROMs or you'll get hard-to-find bugs. They should be good for a hundred erasures or more - not spec'd on my data sheets.

 

You can use an EEPROM like an ATMEL AT28C256, which can be erased and re-programmed on your programmer (no UV) 10,000 times. Flash devices (29Cxxx) are similar.

 

Bob

 

 

 

@bob1200xl

 

Ok but without the wish to be able to program within the Atari, I can use other pin compatible chips to hold my OS ROM?

 

A flash rom or a EEprom...

 

So I don't have to "change" the OS... just put it in such a chip and put it in my Atari, and there I go?

 

The idea of program it with the atari is another wish, but not necessary. My biggest problem is: I don't want to erase my eproms everytime with that UV thing... it fails too many times in my case. Perhaps my eproms are erased already too many times. Does anyone know what the max amount of erase cycles is of a standard 27128 eprom?

 

Greetz

Marius

[Shawn Jefferson]

I saw the MyIDE Internal has a flash OS, which can be updated on the fly? Does it contain two os'es? I guess the atari must be up and running to be able to update it...

 

Hi,

 

The MyIDE Internal by Atarimax does allow you to flash the OS, in system. It also has the stock OS as a failback (that you enable by setting a jumper), so no problem if the flash gets messed up. I suppose you can easily flash whatever OS you want in there (but only one).

[+JAC!]

>So you can update the OS in your atari by loading it from disk into that SRAM chip?

Yes. The SRAM holds 2 of them (2x16). I have an external select switch to choose between normal OS (which is required for example when the SRBAM is empty) and the two banks. That is especially fine if you are testing your own/modified OS. And of course it is "cool" . I created my own OS back then to boot directly from the printer port of my Amiga. When I switched on my Atari it looked like this while waiting for the first byte to arrive.

 

But I'd say for "normal" use, an EEPROM/FLASH would be more suiteable.

 

>Wow. How do I get such a Supermon like yours?

I'm afraid the only way would be eBay. The hardware is actually called "25k BiboMon" and the original manufacturer no longer exists. I bought mine back in the 1990ies. mega-hz is working on a new/revieved version though.

Edited January 1, 2011 by peter.dell