XL/XE compatible Atari 800?

[spookt]

Hi Warerat

 

Mimo just reminded me about this. I have a stock PAL 800 I could drag out over the weekend if you still want a dump? Let me know.

[Rybags]

Are you sure about this PAL OS-A thing?

 

I'd have thought few or no PAL machines had Rev A.

 

Remembering here that PAL machines came out later as well.

 

Also, maybe don't rely on utilities that identify the OS... the 400/800 had stuff like baud rate table and key repeat rate hard-coded dependant on region, so it's entirely possible that an otherwise identical OS could be misidentified.

[sup8pdct]

Every 800 and my 400 I have ever seen has had rev A in it. a cross referance with best catalog with the part numbers confirms this.

Also, the rom part number also included either the letter A for rev A and B for rev B. The annoying part is that the floating point Math rom had the rev B part number.

The 400 (my first computer) also has the rev A bug that has to do with the cassette.

Am not saying rev B never arrived here, just saying I personally have never seen it in rom.

 

James

 

 

Are you sure about this PAL OS-A thing?

 

I'd have thought few or no PAL machines had Rev A.

 

Remembering here that PAL machines came out later as well.

 

Also, maybe don't rely on utilities that identify the OS... the 400/800 had stuff like baud rate table and key repeat rate hard-coded dependant on region, so it's entirely possible that an otherwise identical OS could be misidentified.

[sup8pdct]

Can you please quote the rom part numbers for me please if you get the chance?

There are 3 in total.

 

James

 

 

Hi Warerat

 

Mimo just reminded me about this. I have a stock PAL 800 I could drag out over the weekend if you still want a dump? Let me know.

[spookt]

Sure - but I won't get to it until Saturday.

[spookt]

Well I guess I didn't say which Saturday. Sorry guys I've been a little busy of late

 

OK, here's a picture of the personality board:

 

 

And here's a dump of E000-FFFF:

 

A800.DMP.zip

 

Not sure if anyone still wanted or needed these but here you go anyhow.

[sup8pdct]

Heh. i thought you forgot. How wrong was I?

 

Those roms pictured are Rev A. The part numbers match and I also campared the dump you have with an image of rev A roms avilable with several emulators. Exact match.

 

James

 

 

Well I guess I didn't say which Saturday. Sorry guys I've been a little busy of late

 

OK, here's a picture of the personality board:

 

 

And here's a dump of E000-FFFF:

 

 

Not sure if anyone still wanted or needed these but here you go anyhow.

[Almost Rice]

OK, here's a picture of the personality board:

 

And here's a dump of E000-FFFF:

 

You beat me to it. I was going to get the file off the dos 2.5 image. I could not since I only have the 800 and no xl/xe here. Here it is anyway.

dos25.zip

The file is OS800PAL.OBJ

The chips have the same markings except the chip to the right is C012399B

Also, it is Copyrighted 1982.

Should be of the same range E000-FFFF

Edited March 29, 2009 by Almost Rice

[spookt]

The chips have the same markings except the chip to the right is C012399B

Also, it is Copyrighted 1982.

Should be of the same range E000-FFFF

 

Hmm, I might have to re-check that. Looking at the photo I may have have read the right hand chip wrong it could be a B and not and 8. I'll check later on.

 

IIRC this board is dated 08/83.

[spookt]

The chips have the same markings except the chip to the right is C012399B

Also, it is Copyrighted 1982.

Should be of the same range E000-FFFF

 

Hmm, I might have to re-check that. Looking at the photo I may have have read the right hand chip wrong it could be a B and not and 8. I'll check later on.

 

IIRC this board is dated 08/83.

[+warerat]

Thanks for the data, guys.

[iainjh]

Hi

 

Any recent updates guys? I'd still love to be a queue to buy such a card Any news would be cool.

 

Best, Iain

[iainjh]

Sorry for being so err, 'sad' about this, but the arrival of my SDrive Nuxx is prompting me to ask again

 

Any news or updates anyone?

 

cheers in advance, please forgive the bump on this thread,

 

Iain

[iainjh]

any update please (please )

 

sorry for bugging!

 

cheers in advance.

[mimo]

hopefully not for a good few months now, I am totally skint

[iainjh]

Hi, any recent news on this? Still think this

could be an excellent addition to a stock 800

and the atari 'world' in general.

 

My XL gets the use but the 800

is so cool. Any news (please! Its too good not to ask

 

 

Thanks for any post

 

Iain

[atariksi]

Are you sure about this PAL OS-A thing?

 

I'd have thought few or no PAL machines had Rev A.

 

Remembering here that PAL machines came out later as well.

 

Also, maybe don't rely on utilities that identify the OS... the 400/800 had stuff like baud rate table and key repeat rate hard-coded dependant on region, so it's entirely possible that an otherwise identical OS could be misidentified.

 

Just tried something-- OS-A and B boot up fine w/o the FP ROM. So you could put in a 2K RAM chip there if you don't need the slow floating point libraries and get 50K in Atari 800.

[+Stephen]

Just tried something-- OS-A and B boot up fine w/o the FP ROM. So you could put in a 2K RAM chip there if you don't need the slow floating point libraries and get 50K in Atari 800.

Neat.

 

Stephen Anderson

[iainjh]

Hi all

 

what are the alternatives to making my 800 more XL compatible? by that I mean more ram, maybe port B and so on, to work with more common xl games and demos.

 

I have an 800 and several XL's but really, really would like to use my 800 as the main machine. I use it with an atarimax flash cart and an Sdrive Nuxx but the amount of my favourite games that dont work on the 800 is something I'd like to get round to some degree.. Any clues, web links, help welcomed I've been posting on this thread for a while with no response so I guess I should ask for alternatives!

 

cheers, Iain

[+warerat]

Hi all

 

what are the alternatives to making my 800 more XL compatible? by that I mean more ram, maybe port B and so on, to work with more common xl games and demos.

 

I have an 800 and several XL's but really, really would like to use my 800 as the main machine. I use it with an atarimax flash cart and an Sdrive Nuxx but the amount of my favourite games that dont work on the 800 is something I'd like to get round to some degree.. Any clues, web links, help welcomed I've been posting on this thread for a while with no response so I guess I should ask for alternatives!

 

cheers, Iain

 

Well this is a WIP, and have only been able to spend a little bit of time on it-- so it progresses slowly when it does like most hobby projects. I re-did the design and at this point I have essentially an all-in-one board that can switch back and forth between different three different 800 memory maps (stock 48K, stock 52K, Axlon 512K) and four XE memory maps (stock 128K, 320K, two different 576K). I've had to physically re-work the prototype to allow a larger CPLD to allow for this extra functionality.

 

The point is, it can be done. While the hardware is essentially the same, there are some aspects with the design of the 800 that warrant some extra attention. The simplest option to turn it into a 64K 800XL is to equip your OS board (I've done this in the past and was part of the initial proof-of-concept) with an additional 16K of memory and put the XL OS in ROM with a connection to PIA bit 0. That would provide the minimum compatibility, but you'd still have work to do on the reset circuit, cartridge interlock, and fix a pin on the cart slot (the 800 doesn't supply the phase 2 clock to the cart slot, only RAS). I don't know what level of experience you have soldering or what equipment you have, but it can get rather involved.

[sup8pdct]

Hi all

 

what are the alternatives to making my 800 more XL compatible? by that I mean more ram, maybe port B and so on, to work with more common xl games and demos.

 

I have an 800 and several XL's but really, really would like to use my 800 as the main machine. I use it with an atarimax flash cart and an Sdrive Nuxx but the amount of my favourite games that dont work on the 800 is something I'd like to get round to some degree.. Any clues, web links, help welcomed I've been posting on this thread for a while with no response so I guess I should ask for alternatives!

 

cheers, Iain

 

Well this is a WIP, and have only been able to spend a little bit of time on it-- so it progresses slowly when it does like most hobby projects. I re-did the design and at this point I have essentially an all-in-one board that can switch back and forth between different three different 800 memory maps (stock 48K, stock 52K, Axlon 512K) and four XE memory maps (stock 128K, 320K, two different 576K). I've had to physically re-work the prototype to allow a larger CPLD to allow for this extra functionality.

 

The point is, it can be done. While the hardware is essentially the same, there are some aspects with the design of the 800 that warrant some extra attention. The simplest option to turn it into a 64K 800XL is to equip your OS board (I've done this in the past and was part of the initial proof-of-concept) with an additional 16K of memory and put the XL OS in ROM with a connection to PIA bit 0. That would provide the minimum compatibility, but you'd still have work to do on the reset circuit, cartridge interlock, and fix a pin on the cart slot (the 800 doesn't supply the phase 2 clock to the cart slot, only RAS). I don't know what level of experience you have soldering or what equipment you have, but it can get rather involved.

 

 

Sounds goooooooooood!!!!!!

Can't wait..............

 

James

[atariksi]

Hi all

 

what are the alternatives to making my 800 more XL compatible? by that I mean more ram, maybe port B and so on, to work with more common xl games and demos.

 

I have an 800 and several XL's but really, really would like to use my 800 as the main machine. I use it with an atarimax flash cart and an Sdrive Nuxx but the amount of my favourite games that dont work on the 800 is something I'd like to get round to some degree.. Any clues, web links, help welcomed I've been posting on this thread for a while with no response so I guess I should ask for alternatives!

 

cheers, Iain

 

Well this is a WIP, and have only been able to spend a little bit of time on it-- so it progresses slowly when it does like most hobby projects. I re-did the design and at this point I have essentially an all-in-one board that can switch back and forth between different three different 800 memory maps (stock 48K, stock 52K, Axlon 512K) and four XE memory maps (stock 128K, 320K, two different 576K). I've had to physically re-work the prototype to allow a larger CPLD to allow for this extra functionality.

 

The point is, it can be done. While the hardware is essentially the same, there are some aspects with the design of the 800 that warrant some extra attention. The simplest option to turn it into a 64K 800XL is to equip your OS board (I've done this in the past and was part of the initial proof-of-concept) with an additional 16K of memory and put the XL OS in ROM with a connection to PIA bit 0. That would provide the minimum compatibility, but you'd still have work to do on the reset circuit, cartridge interlock, and fix a pin on the cart slot (the 800 doesn't supply the phase 2 clock to the cart slot, only RAS). I don't know what level of experience you have soldering or what equipment you have, but it can get rather involved.

 

I think main feature would be the ability to have RAM under ROM via PORTB bit 0. How much soldering does that involve?

[+warerat]

I think main feature would be the ability to have RAM under ROM via PORTB bit 0. How much soldering does that involve?

 

Prototype I did for 64K Atari 800 OS board with RAM under ROM-- this was the proof of concept and how it all got started. I made a few of these for some members on this forum. This one I want to say is probably from around January 2006. Three chips (16K EPROM, 32K SRAM, GAL16V8) and about 20 blue-wire connections. That coiled wire connects to PORTB bit 0. In theory you can use the unused pin connection on the OS module (pin 20, third pin on bottom right) and then jumper the slot on the motherboard to PIA bit 0 if you wanted a clean install. The OS on this one was obviously slightly modified to have the reset NMI handler. No switchable BASIC or Self-test available. Bare bones 800XL compatibility.

 

Kind of a kludge, but it worked. Not really 100% compatible but close enough to run most disk-based apps.

[+warerat]

Oops, didn't attach the pictures...

[ClausB]

...fix a pin on the cart slot (the 800 doesn't supply the phase 2 clock to the cart slot, only RAS).

 

The RASTIME signal on cart pin S has the same falling edge as Phi2 but the rising edge is advanced by about a quarter cycle. An LRC delay line (total time constant of 132 ns) and a NAND gate on the Personality Board generate the signal. So, any cart that uses the falling edge (to clock data, for example) would see no difference between the 800/400 and XLs. Any that uses the rising edge to latch the address (as the OSS banking carts do) would also work with both. I doubt it is necessary to change the signal in your mod.

 

BTW, I presume you've noticed the RASTIME and /WRITIME errors in the Hardware Manual schematics. In the Personality Board schematic, those two signal names are swapped. Also, in the 800 Motherboard schematic, the pin labels for those two signals are swapped. You can see the errors if you compare with the equivalent circuit in the 400 Motherboard schematic. I also verified it by tracing the circuits in an 800.