Atari 800 VBXE installation

[candle]

no, i don't

 

[_The Doctor__]

would be cool if you did, as your gadgets and videos are worthy of some gifting!

[Faicuai]

2 hours ago, candle said:

faucuai, you wrote you're busy buying sophia/whatsoever, why are you still here?

obviously you have no clue about power distribution, or power conversion, yet, heared about dc/dc converters and wanted to shine - you're not shining here...

having anemic power supply to start with there is nothing that will save you, 800xl has no power on pbi bus for a REASON, and the only reason there is to it that 600xl has, it's was intended soleyly for 1064 expansion pack - out connector doesn't have 5V on it either

you can try to power some logic with the supply provided, but thinking about powering entrie bus is a dream

current handling of those two pins are 4A, where you think you're going to put them or get them from?

 

and as always -  no incognito, no ride

 

Putting aside the shining-gibberish, here's the origin of my question:

 

As soon as looking (for the first time) the design of that Slot-3 board (and PBI in/out headers). I immediately thought about the 5v. feed provided by Incognito, vs. the -5,+5, +12v provided in Slot-3. This Q. also came in the context of recent testing of Turbo-Freezer on Incognito.

 

The diagram below shows the 800 Power-Board down to its generation / regulation (which is where everything boils down to). And it is clear that +12v and +5v rails are driven separately. They do share the rectifying stage, but they *do not* share the active regulating components. Back-in-the-day, RAM had different, higher powering requirements, and the 800 PS was beefier, for this reason. 

 

So the obvious. common-sense question revolved around why not using the +12v rail (Which is mostly vacant on an 800/Incognito, thus alleviating load on +5v rail, where EVERYTHING we know runs today? A dc-to-dc extra-stage would take care in bringing voltage down to +5, and off-loading any future PBI expansion from the already crowded +5v:

 

 

This question also arises from the fact that I am involved in the design of a new "smart" power-board for the 800 (drop-in replacement), and we found some important issues when studying this case closely.

 

It's not about shining. It's just about simple, common sense questions, that can be quickly answered without extra-drama. That's all.

 

Edited January 26, 2021 by Faicuai

[BillC]

2 hours ago, Faicuai said:

I wonder what their reaction is going to be when they realize that their 48K 800s will become 32K machines

This would be the same issue as for the legacy slot 3 80 column cards, 16kB + 32kB(or a single 48/64kB) RAM cards would be required.

tf_hh makes a 48/52kB card for the 400, it should be possible to modify the 800 to work with it.

I mention modifying the 800 since it wasn't designed to access more than 32kB on a single RAM card.

[+DrVenkman]

3 hours ago, candle said:

and as always -  no incognito, no ride

This is a key point that some people keep overlooking.

10 minutes ago, BillC said:

This would be the same issue as for the legacy slot 3 80 column cards, 16kB + 32kB(or a single 48/64kB) RAM cards would be required.

tf_hh makes a 48/52kB card for the 400, it should be possible to modify the 800 to work with it.

I mention modifying the 800 since it wasn't designed to access more than 32kB on a single RAM card.

See above. 

[Faicuai]

1 hour ago, BillC said:

This would be the same issue as for the legacy slot 3 80 column cards, 16kB + 32kB(or a single 48/64kB) RAM cards would be required.

tf_hh makes a 48/52kB card for the 400, it should be possible to modify the 800 to work with it.

I mention modifying the 800 since it wasn't designed to access more than 32kB on a single RAM card.

Absolutely.

 

But keep in mind that such problem was solved many years ago, already.... 16KB+(n x 16KB ext) cards, on Slot-2.

 

I have an Intec 32KB card that sits on Slot-2 when plugging my Bit3 (on my reference 800). However, the latest sram 512KB expansion that rides on Slot-2 as well, DOES NOT handle the final 16KB required to ensure 48KB of base RAM (and that's a modern upgrade !! 8-)

 

So yes, even if this VBXE-setup is not intended for classical 800 users, there is room for TF_HH magic here (and his beautiful and immaculate boards that look like they came hand-polished out of a German AMG Mercedes factory).

Edited January 27, 2021 by Faicuai

[+Stephen]

6 hours ago, candle said:

faucuai, you wrote you're busy buying sophia/whatsoever, why are you still here?

obviously you have no clue about power distribution, or power conversion, yet, heared about dc/dc converters and wanted to shine - you're not shining here...

having anemic power supply to start with there is nothing that will save you, 800xl has no power on pbi bus for a REASON, and the only reason there is to it that 600xl has, it's was intended soleyly for 1064 expansion pack - out connector doesn't have 5V on it either

you can try to power some logic with the supply provided, but thinking about powering entrie bus is a dream

current handling of those two pins are 4A, where you think you're going to put them or get them from?

 

and as always -  no incognito, no ride

 

Hey man - he's a manager.  He doesn't need to have knowledge of the product or what you do.  Managers just push people around and tell them what to do.  Don't question the all knowing oracle - he has expensive display equipment, precisely NTSC configured you know!

[BillC]

12 minutes ago, Faicuai said:

However, the latest sram 512KB expansion that rides on Slot-2 as well, DOES NOT handle the final 16KB required to ensure 48KB of base RAM (and that's a modern upgrade !! 8-)

The issue isn't with the 512kB SRAM card, it's that Atari only designed the RAM slots for 32kB boards maximum, the only RAM slot on the 400 also has a 32kB limit, which is why all the larger 48/52kB RAM cards for the 400 require some jumpers on the bottom of the PCB to add the extra signals required to the RAM slot.

 

The 48/52kB card from tf_hh also has a ribbon cable that connects to the socket for Z103 on the 400 PCB, this may only be for disabling the stock ROMs when using the external EPROM on the RAM card but there are other signals it could be using as well.

 

There is a thread where @ClausB discusses how the 800 handled RAM selection. He mentions that a 32kB card by one manufacturer only works in RAM slot one and another by a different manufacturer only in RAM slot 2 because they didn't properly follow the selection method. Post# 64 list pins to be connected on an 800 PCB to use an Atari 48kB card in RAM slot 1 while post# 65 has an image of this, post # 87 shows modifications for an Atari 48kB card to work in RAM slot 1 with an Axlon 128 in RAM slot  2 and a non-RAM board in slot 3(no modifications to the 800 PCB), but only 32kB of the the 48kB Atari board is used.

 

 

[candle]

just documentation

i would like to get one manufactured myself before anyone would put their money into something that wasn't checked

vbxe_slot3_carrier.PDF

[CMinus]

Can we use Flex cable? It would dramatically reduce the height requirement.

[candle]

FFC? where?

 

[candle]

https://www.pcbway.com/project/shareproject/VBXE_Atari_800_carrier_board.html

 

 

[+Stephen]

3 hours ago, candle said:

https://www.pcbway.com/project/shareproject/VBXE_Atari_800_carrier_board.html

Fantastic!

[flashjazzcat]

Video showing installation of the VBXE adapter board:

As per my prior attempt using point-to-point soldering some years ago on the same 800, D6 decoding (i.e. FX core functionality) didn't work, although RGB output was functional before the motherboard died for reasons not yet established. Candle's 800 VBXE installation apparently works perfectly, meanwhile, the only difference being that his machine lacks the SCCC board by @tf_hh, and this is apparently the variable I am invited to eliminate in order to fix D6 decoding and Incognito NVRAM issues on cold power-up when using the VBXE-enabled Incognito JED. I look forward to doing so in a subsequent video.

[+Stephen]

I am intrigued.  My Incognito 800 also has a Super Colour CPU.  I have a stock 800 (and an extra Incognito).  I'm very tempted to order and populate one of those VBXE carrier boards, and try an 800 with & without the extra CPU card.  It will be easy for me to put the regular card back - I only installed it because the 800 had a video output issue (easier to install that card than to diagnose it before the show I was attending).

 

I will take stock of (literally) the situation tomorrow and see what I may need to pull this off.  Oh - assuming my Incognito has the proper JED (and I am allowed to update it not so smiley face)

[candle]

"allowed"?

 

without jed update you'll have unitialised gtia registers after power up, so picture will be unreadable (it defaults to text mode in 16 shades of one colour)

plus vbxe must be enabled in incognito bios too

 

[flashjazzcat]

12 hours ago, Stephen said:

Oh - assuming my Incognito has the proper JED (and I am allowed to update it not so smiley face)

You can grab the most recent JED from this thread:

 

[candle]

or just to be sure, from here

 

main.jed

[flashjazzcat]

I have everything working now; video to follow tomorrow.  Turns out I was trolled in the most unexpected way possible - by a malfunctioning Incognito board.

 

[Tuxon86]

52 minutes ago, flashjazzcat said:

I have everything working now; video to follow tomorrow.  Turns out I was trolled in the most unexpected way possible - by a malfunctioning Incognito board.

 

If I remember from your previous video, it was the only piece of hardware you didn’t suspect of being the culprit… 

 "It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth." ~ Sherlock Holmes

 

[flashjazzcat]

Absolutely, although personally I found it difficult to imagine how the SCCC could cause the issue either, and clearly it didn't. But I would have been happy to eliminate it for testing had this proved necessary.

[_The Doctor__]

was the incognito simply in need the jed and flash treatment or was it something more insidious?

[flashjazzcat]

7 minutes ago, _The Doctor__ said:

was the incognito simply in need the jed and flash treatment or was it something more insidious?

Something more insidious. Even before it stopped booting (which might in itself be an easy repair), it behaved differently with the newer JED to the spare board when VBXE is present.

[+DrVenkman]

At risk of sidetracking Jon's thread, are there instructions somewhere for flashing the Incognito jed? I have a TL866-II and a bunch of CPLD socket adapters and the like, but I'd hate to make a rookie mistake that can be avoided with wisdom from others who've done it.

[+Stephen]

43 minutes ago, DrVenkman said:

At risk of sidetracking Jon's thread, are there instructions somewhere for flashing the Incognito jed? I have a TL866-II and a bunch of CPLD socket adapters and the like, but I'd hate to make a rookie mistake that can be avoided with wisdom from others who've done it.

I am pretty sure you have to have an Alterra blaster and the appropriate cable to update the CPLD on these.

https://www.amazon.com/waveshare-USB-Blaster-V2-Programmers/dp/B08CV3L6LF