New Twist on a Very Good 1200XL Upgrade

[Gunstar]

 

Fairly sure the LEDs tap the PORTB outputs directly (the schematics from Jerzy Sobola have no reference to them on the PIA page) so the MMU in use should be irrelevant.

But... the OS code for the later XLs and the XEs retains the F-key code which should mean in theory that a 1200XL configured as a 130XE would allow the user to inadvertantly alter the extended banking which would be a bad thing.

I've been using my 1200XL for years with newer and custom OS's on the 32-in-1 and extended memory with no issues when using the built-in 1200XL F-keys. But, IIRC, those are controlled by bit 7 of PORTB, which is not used by extended memory of 256K or less. With my Atarimax Rambo, which supports both 256K and 512K, which I select with a switch, it automatically disables and enables the advanced 1200XL features when I switch between the modes. That is, when I used too. I have since reverted back to 256K only mode, due to issues with pressure on the piggy-back dram chips from the keyboard.

 

But I now use Sys-check's 512K external sram always enabled, and in this situation only 64K of internal memory from the Rambo is used and 512K extended from Sys-Check. I use the 1200XL's function buttons all the time, and use SDX and other things in extended memory, and as of yet have had no conflicts with the F-keys and extended memory with the Sys-check memory either, which is Rambo compatible, but then maybe since it's external memory it works differently than internal extended memory? This would be a new concept to me.

 

But in either case, I have been happily using my 1200XL's F-key functions, all of them, including functions with CONTROL key combination, with no conflict or issue due to inadvertent bank-switching that I have ever seen. Maybe I have just been lucky so far, in that I haven't been using more than 256K extended memory at the times I've used the F-keys, which is totally possible, I just hadn't thought of it until now. But in any case, from my experience, the 1200XL's F-key functions don't conflict with 256K or less extended ram.

Edited March 6, 2019 by Gunstar

[flashjazzcat]

SysCheck's external 512K RAM is controlled by PORTB, and the 1200XL's LEDs are controlled by PORTB bits 2 and 3. As I understand it, these bits will be altered by CTRL+F1 (enable/disable keyboard) and CTRL+F4 (toggle domestic/international character set), and the code to handle them is present in the standard XL/XE OS.

[Gunstar]

Then I mis-remembered it being bit 7. Well, I have never used the international character set, but I do the keyboard enable/disable and as of yet, have never noticed any issue. I guess I've been lucky in that when I've used it I haven't been using extended memory. But I do know from experience, that my 1200XL's functions have always worked with my Rambo memory in the situations I've used them, with no ill effects.

[_The Doctor__]

other than twinkling lights I've not seen an issue where the possible conflict has come up. My experience is that of Gunstars' in that realm

[flashjazzcat]

I'm sure it's possible to go through life without ever encountering an issue, but the fact remains that if the keyboard handler happens to flip bit 2 or 3 of PORTB to the opposite value to that required by any software accessing a bank of extended RAM at that time, problems are guaranteed. I can crash SpartaDOS X running in extended memory here during a directory listing simply by pressing CTRL+F4 repeatedly until suddenly the wrong bank of RAM appears at $4000-$7FFF.

[_The Doctor__]

That could be fun, going through stuff and toggling the crap out of whatever to see if we can crash it. Not exactly what most folks do- but it is part of the hobby

Edited March 6, 2019 by _The Doctor__

[flashjazzcat]

Yeah. Do you also argue with yourself? Re-read what I just posted above. Where do I advocate 'toggling the crap out of' anything? It's possible to avoid issues long-term but just because you avoid them, does not mean the potential does not exist. You may have heard of software testing, where the objective is to establish the robustness of a program and see if unexpected input can crash it. Well: I just reproduced an example of that.

 

So: the potential to crash the machine exists, whether you like it or not. If you disagree that this is objectively the case, prove me wrong.

[_The Doctor__]

wow try have some fun and see what happens. I've never been a fan of port B memory implemented as it was, I'd rather it was handled with a latch etc. You will find it's consistent. But I do advocate the cheap Peterson upgrades since this what people ran with. The whole led/ switching / int.char.set thing is a horse we've beaten to glue before. I suppose an industrious person could re organize things and make it unlikely to happen, perhaps a new OS etc. or select something in the 32 in one choices that doesn't touch that. I suppose if you have a toggle switch to enable or disable Rambo, it could be wired to disconnect the offending keys as well so on and so forth...

 

I would like to think we all should argue points with ourselves if we are to be intellectually honest. But one would have to be able to handle the slings and arrows of being a critical thinker in their own being and accept the same from others.

 

If I could have used a troll emoji I would have but it was posted in fun with a smiley face. Perhaps the sarcasm didn't come through? I will try to be more over the top with it next time.... ah subtlety

Edited March 6, 2019 by _The Doctor__

[flashjazzcat]

I couldn't care less about the practical implications and or workarounds because it's quite obvious that one can simply avoid the contrivance of pressing CTRL+F4 and that is end of the problem for those of us who don't want to turn the keyboard off. Conversely (for those of you who do), one can turn the keyboard on and off every day and assume there's no possibility of an issue because no issue has been observed.

 

Two of the 1200XL's F key combos may interfere with your PORTB RAM. The end.

Sarcasm requires tags on the Internet. However, if a smile will suffice, why then are you encouraging me to 'have fun' when my post also included a smilie?

[Gunstar]

I'm sure it's possible to go through life without ever encountering an issue, but the fact remains that if the keyboard handler happens to flip bit 2 or 3 of PORTB to the opposite value to that required by any software accessing a bank of extended RAM at that time, problems are guaranteed. I can crash SpartaDOS X running in extended memory here during a directory listing simply by pressing CTRL+F4 repeatedly until suddenly the wrong bank of RAM appears at $4000-$7FFF.

I decided to do some testing of this, since it did occur to me that I hadn't used the functions lately, since I got my system setup the way I like, as I showed in the video on Atari Sector (FJC knows of this, whom I am replying too, so don't worry, other people, if you don't know what I am talking about). Yes, indeed the keyboard disable screws things up and so does the international character set, but the DMA screen disable and keyboard click disable work perfectly fine. And of course my cursor control still works fine. When not using SpartaDOS, BANKED, everything works fine and under every other circumstance I've used since expanding memory about 15 years ago, for the first time on my 1200XL, and since then the 1200XL's extended OS functions work perfectly fine with my Rambo memory upgrades. So while using SpartaDOS I have to stay clear of international character set (never used it anyway) and locking the keyboard.

Edited March 6, 2019 by Gunstar

[Gunstar]

That could be fun, going through stuff and toggling the crap out of whatever to see if we can crash it. Not exactly what most folks do- but it is part of the hobby

That's just what I decided to do (not seeing your post here) and my results are above.

 

 

But my whole point was that many "experts" have said that extended memory disables the 1200XL's special OS features and that is simply not the case at all from my experience. And no, I am not referring to anything said in this thread.

Edited March 6, 2019 by Gunstar

[_The Doctor__]

but I thought we were having fun some of us are.

Edited March 6, 2019 by _The Doctor__

[Kyle22]

I ran 1200XLs for a long time. It is NOT good to make the L1 and L2 LEDs change state by USER input. Bad things happen. Just watch the pretty lights blink while the system is working. DMA off is FINE. I never turned click off too much, but as long as it doesn't change the status of L1, L2, it should be OK.

[Gunstar]

Yeah...I have those LED's re-purposed...I didn't need verification of using those functions since there are other obvious signs...

[Kyle22]

Yeah...I have those LED's re-purposed...I didn't need verification of using those functions since there are other obvious signs...

I agree w/ you 100% on the 1200xx/1400xx LEDs.

 

What I want to comment on is what Nolan says in your Sig. line.

 

This is the PERFECT example of why a Representative Republic works, and a democracy ALWAYS fails. Only stupid people love MOB RULE. Nolan Bushnell is a Brilliant man!

 

Edit: Clarification. Added the word 'only'.

Edited March 7, 2019 by Kyle22

[Marius]

That could be fun, going through stuff and toggling the crap out of whatever to see if we can crash it. Not exactly what most folks do- but it is part of the hobby

TBH... this is exactly a description of my beta testing procedure. The reason some software packages here in the a8 scene do work so incredibly well, is because they are tested in this way. Simply trying to crash it in every possible way. You'll be surprised how many future trouble this saves you.

 

This is btw the motivation why I am not a fan of game developers and salesman who only deliver their game on cart. Sooner or later a real problem occurs and then it is harder to fix.

 

I found several issues in some games which were serious enough to spoil the fun on PAL systems which a so called betatest team did not find.

 

And besides that. The reason I am so serious about curing even theoretical issues is that you simply do not know how you will use your system in the future.

 

I was NEVER interested in SDX before. I could simply not imagine that I would ever use that dos. So issues people did run into in the past with MyIde and SDX? I laughed it away and told people: why bother you really don't need this. Use another DOS instead. (Like: this is not a real issue)

 

Until I found out how great The Last Word, word processor is and that, if I would use it the way I wanted it to Use, I'd better move to SDX. Well... There I was with my setup that seemed to be the best possible setup so far.

 

What I try to say is that what looks like a non-issue to person A, could simply mean a real life issue to person B. Software designers like FJC are praised by me by the fact that they indeed try to beat the hell out of their software before they release it. It is the reason why his stuff is so extremely powerful and so well constructed.

 

I know it is sometimes difficult to see sarcasm or a joke in written language. Especially if you are not a native speaker like me. But on the other side. The comment you made which I quoted is a philosophy more people actually have and express. Why bother when it works?! And I truly think that is the most dangerous thought in software (and hardware) development. So joke or not... I found it important enough to reply about.

 

Oh and one last reality example.

My Atari is also used by my daughter. She likes to play games. She does not know about memory expansions or keycombinations or whatever. She simply wants to switch on the atari and plays Joust or Qix. Every time I make a change to the system she is like: hey dad... Why can't I start my favourite games anymore?

 

So this gives me a different point of view on software development. When I betatest stuff, I now think by default: is it clear enough for non-informed users, to use this?

 

I indeed could imagine that one day when I am gone, my daughter still would like to play Atari with her future kids. And if my system is so complicated with all kind of bells and whistles she will probably never get at the point of playing the games (or getting into my documents or whatever she wants to reproduce). So yes... when I make changes to my atari use... I keep thinking of that: do not create a technological challenge to the future users of this system Marius

 

Hehe you see to what a joke can lead haha.

Anyway... have fun with a8. It's great stuff!

Edited March 7, 2019 by Marius

[_The Doctor__]

Marius,

This is exactly the kind of response I was hoping for. You have summed up everything in a clear to understand how and why. I've been a tester for years and I may be referring people to your post in the future. It will save me the convoluted conversation normally to be had. I remember, back in time, some conversations where you indeed said just use such and such it works and I bickered a bit about it saying I use this device or that DOS and want to use this with all of them. Very few people ever admit their views changed or have grown. You did just that! I like that you chose to stay and what you say. Thank you for sticking with us. Top notch my friend.

 

I still think Prowizard or Marius1976 when I see your name

 

_Doc B

[hueyjones70]

I actually meant 24 pin b ecause on of the previous posts called for a 24 pin. I have already installed a 28 pin socket so I would prefer to use the 28 pin eprom and install the jumpers.

[Gunstar]

 

I was NEVER interested in SDX before. I could simply not imagine that I would ever use that dos. So issues people did run into in the past with MyIde and SDX? I laughed it away and told people: why bother you really don't need this. Use another DOS instead. (Like: this is not a real issue)

 

 

I know you are passed this now, as the rest of your post relates, but when people say stuff like this, I guess they just don't realize how important different DOS's are to different people. One might as well be saying; why bother with Atari when you can use Commodore instead, or why bother upgrading your Atari when you can just use an Amiga or ST instead, or why bother using old computers when you can use a modern PC instead?

 

You either get it, or you don't, I guess. At least some people continue to learn and expand their knowledge and horizons as life goes on...and their opinions can change. Who knows? Maybe I will even discover a reason to like MyDOS someday...but in this case it's like trading in a Ferrari for a Yugo...

[Gunstar]

I actually meant 24 pin b ecause on of the previous posts called for a 24 pin. I have already installed a 28 pin socket so I would prefer to use the 28 pin eprom and install the jumpers.

If someone hasn't already helped you, go ahead and send Steve at Atarimax an email, it can't hurt to see if he will sell you one. If you are a regular customer, he may even send one for free. He's sent me free GAL chips more than once, though I had bought the items that require them, but it was long past the time to expect free replacements for them, even if there were a stated warranty. Dropcheck just recently did this for me as well, I only payed shipping.

Edited March 7, 2019 by Gunstar

[hueyjones70]

On 3/6/2019 at 11:23 AM, Gunstar said:

Since Steve at Atarimax sells a 1200XL kit (for 32-in-1 OS) which includes a new MMU and an EPROM of BASIC C, I suspect he would have them. Email him, he may be willing to sell you just BASIC C eprom separately.

 

EDIT: I am assuming you meant a 28-pin eprom, which is 14-pins per side. The original socket on the 1200XL is a 24-pin socket, but the board has room for 28-pin, but some jumpers have to be moved and the MMU swapped out too. I'm not sure if you are planning on using the BASIC eprom on a 1200XL or not, just pointing this stuff out considering the thread title.

I should have given you a "thank you" for the info. I decided to go with the 32-in-1 on that 1200XL. Now I am working on another and I want to do the internal basic and use an eprom with the XL/XE OS and Omniview XL

[Gunstar]

2 hours ago, hueyjones70 said:

I should have given you a "thank you" for the info. I decided to go with the 32-in-1 on that 1200XL. Now I am working on another and I want to do the internal basic and use an eprom with the XL/XE OS and Omniview XL

Nice. I still have my 32-in-1 in my 1200XL "every day" computer. I have a second ready to be installed in another 1200XL too. I also purchased 2 of @Dropcheck 's 4-in-1 OS boards which are getting installed in a 3rd 1200XL and an 800XL. Though I've modified both with piggy-back eproms to be 8-in-1's with an additional switch to choose which 27512 eprom is activated. I actually have more than 32 OS's on my "every day" 1200XL as it has a PBI port and I use a Syscheck XL for extended memory and an additional 3 OS's (and Syscheck diagnotsic OS). Yes, it's uber-overkill and I may decide to trade out the 32-in-1 with the other 1200XL's 8-in-1.

Edited December 30, 2020 by Gunstar

[hueyjones70]

I am working on this mod.  When the instructions say to pull out all of the jumpers except 11, 12, and 13 and my 1200XL doesn't have jumpers in those places, am I supposed to insert jumpers in those places.

[+bob1200xl]

11, 12, and 13 are the jumpers you need for 28 pin EPROMs, so if you will be using 28 pin rather than 24 pin devices, you must add them to your m/b.

 

Bob

[hueyjones70]

I have semi-completed the mod. The computer now boots to self-test unless I have a cart inserted. If I have a basic cart inserted everything seems normal. I believe I have faithfully followed the instructions and I have triple checked everything but i often hard to detect your own mistakes.