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RCA Studio II GOLD MINE! An interview with the Studio 2 Production Manager!


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Great to know the final known US Studio II cart has now been dumped. (Ignoring any potential "betas" or tapes such as the possible colour demo of the Studio III)

 

 

A question to "ajavamind" (Andrew Modla) do you know/have any record of who the author of the tester cart was? I am guessing Joseph Weisbecker?

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I cannot say for certain who wrote the tester cartridge, most likely Jack Wright (Test Engineer) and collaborating with Tom Chen, hardware engineers that I worked with at the Sarnoff labs.

I vaguely recall Jack demonstrating the test program.

I am not sure if engineers in Distributor and Special Products division may also have some contribution or input to the tester cartridge code/operation.

-Andy Modla

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I was able to extract the Arcade "Swords" game by Joe Weisbecker from the cassette tape WAV file (thanks to @ubersaurus) and wrote additional code to emulate the RCA Arcade console to run it.

Here is a screen capture of a sample game play:

 

I will put the WAV extraction program in a new Github repository when I find time to get it ready for publication. I will also update the archive at https://github.com/ajavamind/rca-studio2 for the arcade console emulation after I make some more edits .

 

Now we can see how this game worked in 1975 before Studio II.

 

Andy Modla

Might this count as the first fighting game, or is there an earlier example?

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Hello,
About a month ago, the eBay auction for the RCA Studio II Tester No.1 and Demo cartridges ended.
I've been in contact with the purchaser of them and have assisted in dumping both of them. The buyer wishes to remain anonymous, and I'm going to honor that wish.
I am going to reflash my multicart to include these two files. I will post when I have it tested.
ED

 

 

Awesome work getting these carts dumped - a great piece of history preserved!

 

There is some bad news however: the test cart uses some funky memory mapping, which means that it will not readily run on the multicart - or at least not without some modifications... The author of Emma 02 figured out that the cart starts as normal, but quickly switches to an address in the 0x4000 range, where it expects the cartridge to be mirrored. Not entirely sure why it does this, but it seems to be needed to test the system's ROMs and RAM.

 

Interestingly, it also switches the machine to a high resolution mode (which is relative: 64 x 128), showing 4 memory pages: the top half is the top of the cartridge ROMs (0x0600-0x7FFF) and the bottom half is RAM (0x800-0x9FF). It then goes on testing the RAM, by filling it with 0xFF and writing 0x00 to the addresses and a few other patterns...

 

The hardware of the multicart doesn't map anything above 0x0FFF, because it only has a 4-bit latch - that means it has 12 address lines. A good thing is that if the console tries to use an address above that, it just sees the same, i.e. the first 4K are simply mirrored. But since the first 1K (0x0000 - 0x03FF) is mirrored to 0x4000 - 0x43FF (where the cartridge is expected to be), jumping into that region creates problems, i.e. a crash

 

It is however possible to patch the cartridge, so it stops jumping to an area that it not compatible with the multicart.

 

these are the patches needed:

0x0417 0x43 --> 0x07

0x041F 0x42 --> 0x06

0x0422 0x40 --> 0x04

0x0601 0x41 --> 0x05

 

This stops the program crashing: the memory test runs as does the one for the keypads. On my main test machine, it shows a 'digital failure' as it's called in the service manual by showing 3 & 4 in between the two keypads... I need to dig a bit deeper as to what this means, but it could be linked to not running the program from the correct memory bank... I've attached an image of the test card running on real hardware + multicart.

 

Also attached is a new image for the multicart flash memory, which includes the test card (in slot 4-6). I've moved the demo cart to this bank as well (4-7). Empty slots have a placeholder now, which shows an image on the Studio II (rather than black screen or crashing). If anyone needs this written to their flash chip: either contact me or anyone with an programmer that can handle a 39sf040 flash chip...

 

FliP

post-41391-0-33919000-1517521428_thumb.jpg

39sf040.auto.bin

Edited by flip
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Awesome work getting these carts dumped - a great piece of history preserved!

 

There is some bad news however: the test cart uses some funky memory mapping, which means that it will not readily run on the multicart - or at least not without some modifications... The author of Emma 02 figured out that the cart starts as normal, but quickly switches to an address in the 0x4000 range, where it expects the cartridge to be mirrored. Not entirely sure why it does this, but it seems to be needed to test the system's ROMs and RAM.

 

Interestingly, it also switches the machine to a high resolution mode (which is relative: 64 x 128), showing 4 memory pages: the top half is the top of the cartridge ROMs (0x0600-0x7FFF) and the bottom half is RAM (0x800-0x9FF). It then goes on testing the RAM, by filling it with 0xFF and writing 0x00 to the addresses and a few other patterns...

 

The hardware of the multicart doesn't map anything above 0x0FFF, because it only has a 4-bit latch - that means it has 12 address lines. A good thing is that if the console tries to use an address above that, it just sees the same, i.e. the first 4K are simply mirrored. But since the first 1K (0x0000 - 0x03FF) is mirrored to 0x4000 - 0x43FF (where the cartridge is expected to be), jumping into that region creates problems, i.e. a crash

 

It is however possible to patch the cartridge, so it stops jumping to an area that it not compatible with the multicart.

 

these are the patches needed:

0x0417 0x43 --> 0x07

0x041F 0x42 --> 0x06

0x0422 0x40 --> 0x04

0x0601 0x41 --> 0x05

 

This stops the program crashing: the memory test runs as does the one for the keypads. On my main test machine, it shows a 'digital failure' as it's called in the service manual by showing 3 & 4 in between the two keypads... I need to dig a bit deeper as to what this means, but it could be linked to not running the program from the correct memory bank... I've attached an image of the test card running on real hardware + multicart.

 

Also attached is a new image for the multicart flash memory, which includes the test card (in slot 4-6). I've moved the demo cart to this bank as well (4-7). Empty slots have a placeholder now, which shows an image on the Studio II (rather than black screen or crashing). If anyone needs this written to their flash chip: either contact me or anyone with an programmer that can handle a 39sf040 flash chip...

 

FliP

 

Would a system not getting enough amperage for the test to run also potentially cause error codes? The test cart is stated that it needs 500mA.

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Would a system not getting enough amperage for the test to run also potentially cause error codes? The test cart is stated that it needs 500mA.

 

Interesting thought, but I don't think so: I imagine that the test cart has more chips than a standard cart and that this pushes the power supply just above the normal power supply's limits. But the multicart draws less power overall than any normal cartridge to start with: on my test system (admittedly with a modern dc/dc converter rather than an inefficient 7805 regulator), I draw less than 200mA with the multicart running...

 

It just occurred to me as well that I should be able to map the test cart to 0x4400 rather than to 0x0400 (which is what the patches above do). I'll see whether that makes any difference...

 

It's strange that the system manual doesn't mention what the 'digital failure' codes mean: there seem to be 8 slots, so I assume they refer to the 4 ROM and 4 RAM chips. There's no point in having a CPU or video chip fail indicator as none of this would show... But which chip is which in code is not immediately clear - unless i've missed something in the service manual... It's possible that the test cart somehow switches the internal game roms back on after initializing the test and calculates a checksum. On the multicart, that would be a wrong checksum as it sees the test cart rom rather than the internal game roms...

 

It's a lot to ask for, but it would be really interesting to see the insides of the test cart...

 

FliP

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Hi FliP,

 

I believe the tester SW compares the ROM in loops of 0x200 addresses. It compares 0-0x7ff with 0x2000-0x27ff. If it finds a difference in the first loop it shows a 1, second 2 etc. So 34 means it found a difference in the cartridge ROM on 0x400-0x7ff compared to 0x2400-0x27ff.

 

That is how I understood the code when I tried to implement the mirroring in Emma 02, not 100% sure!

 

I expect higher numbers to indicate RAM issues but haven't checked the code or tested it....

 

I agree it would be nice to see the PCB or schematics for the tester cartridge.

 

Cheers, Marcel.

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Hi FliP,

 

I believe the tester SW compares the ROM in loops of 0x200 addresses. It compares 0-0x7ff with 0x2000-0x27ff. If it finds a difference in the first loop it shows a 1, second 2 etc. So 34 means it found a difference in the cartridge ROM on 0x400-0x7ff compared to 0x2400-0x27ff.

 

That is how I understood the code when I tried to implement the mirroring in Emma 02, not 100% sure!

 

I expect higher numbers to indicate RAM issues but haven't checked the code or tested it....

 

I agree it would be nice to see the PCB or schematics for the tester cartridge.

 

Cheers, Marcel.

 

I've adapted the code - it now runs from 0x4400 but it doesn't make a difference. What does make a difference is to use the little switch on the multicart that determines whether the the first 1k is mapped from the cart or from the console... I've attached the new image, with the code patched as mentioned before...

 

I also tested what happened when using (known) bad chips: a bad rom on the console started the memory test, but with a corrupted screen. The keyboard test crashed as soon as it started. A bad (video) RAM skips the memory test, and goes directly to the keypad test. For the video RAM chips, it gives a failure in 5 & 6, i.e. it marks both as bad meaning it doesn't detect the problem at bit level (each RAM chip handles 4 bits). I am assuming that a failure in the working memory ram would result in codes 7 & 8, though the cart crashes when I put a bad chip in there (not unexpected)

 

I am guessing that a failure of the normal kernel would show 3 & 4 and of the built-in game ROMs would flag as 1 & 2...

 

given that I've had to patch the cart to run on the multicart, I am not entirely sure that it would effectively test the consoles hardware as intended... I think for that purpose, the test I wrote (and that came with the multicart) is a bit more reliable...

 

FliP

39sf040.auto.bin

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Hello,


I haven't been able to run the tester 1 code on real hardware either. It just crashes the Studio II.


I've made a request to the tester 1 cartridge owner asking about the possibility to open the cartridge and take pictures. It's a "big ask" I know, but I'm hopeful.


@flip and extmato:

Nice work guys!

If I can do anything to help, just ask.


ED

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I'm getting another lot of tapes from the Hagley digitized in the next couple weeks - a couple more arcade tapes, some demo tapes, VIP programs, and what I assume are either WIP or final builds of commercially released games (Biorhythm, Baseball, etc.). But what also caught my eye is that the library also has seven punch cards from the Weisbecker collection. There's reason to believe these could be from Joe Weisbecker's original System 00 computer - might be worth figuring out a way to pull the data off them and see if the existing 180x emulators could be modified to read it too. I'd welcome any suggestions on that front.

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might be worth figuring out a way to pull the data off them and see if the existing 180x emulators could be modified to read it too. I'd welcome any suggestions on that front.

 

In terms of getting the data from the punch cards into a digital format, I suspect that the best method would be manual data entry.

 

Even assuming that you could find card reader hardware compatible with a modern computer, I doubt that the archives would be willing to risk damage to the original cards. If (like most other punch cards I have seen) they are on very thin cardboard, they would be fairly brittle by now.

 

I would ask for an enlarged photocopy (blow it up onto an 8.5x14/A4 sheet) or a really good quality JPEG image. Once you figure how the data is formatted on the card (e.g. in rows or columns), it is just a matter of manually recreating the file in a format that the emulator can read. Entering the data from just seven cards is not too onerous a task.

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Just to note about the dump(s) from the Tester 1- it may be hasty to assume that it is the only version of Tester I, and not simply a prototype PROM board much the same as the Demonstration proto board. We still can't rule out that Tester I would be in a normal cartridge, just as the Demonstration is. That in turn might indicate that there are ROM and/or hardware/board differences, however slight. While the white PROM board could indeed be the final version, it also not surprise me if there's also a Tester in a normal cartridge shell. What we have is a dump of a version, but not necessarily the only version. I have no actual confirmation one way or another, just a hunch. This could still be a rare instance of a prototype/PROM board turning up before the finished version.

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I'm getting another lot of tapes from the Hagley digitized in the next couple weeks - a couple more arcade tapes, some demo tapes, VIP programs, and what I assume are either WIP or final builds of commercially released games (Biorhythm, Baseball, etc.). But what also caught my eye is that the library also has seven punch cards from the Weisbecker collection. There's reason to believe these could be from Joe Weisbecker's original System 00 computer - might be worth figuring out a way to pull the data off them and see if the existing 180x emulators could be modified to read it too. I'd welcome any suggestions on that front.

 

Keep up the great work on this- we're all really looking forward to what comes next! :)

 

There's more than 7 punchcards, which I'm sure we'll actually see soon enough. I have no idea what they're from, though- there wasn't much in the way of documentation for them.

 

In terms of getting the data from the punch cards into a digital format, I suspect that the best method would be manual data entry.

 

Even assuming that you could find card reader hardware compatible with a modern computer, I doubt that the archives would be willing to risk damage to the original cards. If (like most other punch cards I have seen) they are on very thin cardboard, they would be fairly brittle by now.

 

I would ask for an enlarged photocopy (blow it up onto an 8.5x14/A4 sheet) or a really good quality JPEG image. Once you figure how the data is formatted on the card (e.g. in rows or columns), it is just a matter of manually recreating the file in a format that the emulator can read. Entering the data from just seven cards is not too onerous a task.

I've actually seen a few of these punchcards and they weren't in bad shape at all. As with the tapes, they seem to have held up over the years. I didn't actually handle them, though, and I especially did not switch their order around at all. Surely something can be done with them, as it is very likely that they are still in the 'proper' order that they were put in back when they would last have been used.

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I read through the history. That's quite a few versions of the hardware!

 

Studio II Point-of-Purchase Demo says "code lost". I assume that's the demo cart dumped about a year ago. Or did you mean some sort of source code document, not just the ROM dump?

 

http://atariage.com/forums/topic/209519-rca-studio-ii-gold-mine-an-interview-with-the-studio-2-production-manager/page-42?do=findComment&comment=3677379

 

How does the Toshiba Visicom fit in? My assumption has been that Toshiba licensed the Studio II, then made their own modifications and some unique games.

Toshiba, along with all of the other companies that sold clone systems, actually licensed Studio III tech, not Studio II (beyond the games). They probably were behind the specific modifications and games in Japan, though. Probably. The Visicom exclusives are the only Studio games that can't be shown to have originated here in the US.

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Just a heads-up that the MAME folks are also aware of the Swords Arcade machine and we might see this in future releases:

 

http://www.mameworld.info/ubbthreads/showflat.php?Cat=&Number=373234&page=0&view=expanded&sb=5&o=&vc=1

 

https://mamedev.emulab.it/undumped/index.php?title=Category:RCA

 

It's also worth noting that some machines were called Fredotronic, Fredtronic, dedicated to Swords, Mines, or other names. There seems to have been at least 10 different arcade machines that were made and tested.

 

I've also been trying to find more contemporary images of the arcade that was at the Cherry Hill Mall in NJ, as that was the mall the Arcade machines were tested at. There might have been others, but that was definitely one.

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Blazing Lazers and I visited the Hagley museum today - I got proper scans of the Studio III and arcade machine photos previously seen some pages back, but also dug through quite a bit of paperwork. I turned up some concrete information on release dates:

 

RCA started talking about test marketing the Studio II in November of 1976, according to dated preliminary versions of the system manual. It's possible that staff members were taking the machine home to test with family members around this time. Even as early as March 5, 1976, Weisbecker was reporting that the logic for the "Cosmac RG Home" was in the final stages - he was referring to the Studio II.

 

The Studio II was test-marketed in four cities: Indianapolis, Oklahoma City, Portland Maine, and Spokane - this took place in February (and based on the information previously posted about its sales, RCA started counting registration cards to get sales numbers Feb 15, 1977). Positive feedback caused them to increase their test markets to 19 until a national rollout occurred in April. The Studio II hit those test markets with three games at launch:Space War, TV Schoolhouse 1, and Fun With Numbers.

 

In April (possibly late in the month), Tennis/Squash came out. Baseball followed around May 15, 1977.

 

Blackjack was the next game out, and was projected as being available by the end of the summer.

 

The specific release dates for Math Fun, Speedway/Tag, and Gunfighter/Moonship weren't noted in any paperwork I saw, but Biorhythm was the 10th game to come out and released on November 15, 1977. The same press release notes that Speedway and Gunfighter were "recently announced," which I read as having come out shortly before Biorhythm. Given that nothing else mentions those other three games, I can assume they all came out in the early fall.

 

And of course, after the system was discontinued by RCA in February 1978, the entire stock was sold to Radio Shack for liquidation. I didn't grab scans or photos of them, but I did come across periodicals discussing how one could make a PROM cart for the Studio II that would allow one to use it as a low-cost computer.

 

 

I found a boatload of other items of note too, including some information on the VIP II and its potential lineup of games (as well as a few details on the Studio III and IV that may have already been mentioned in this thread, I gotta check). Also fun: the costs of building the arcade machines, of which it seems like RCA made six units (public feedback was apparently not encouraging, hence why they dropped them). I'm attaching those particular breakdowns.

post-372-0-29812700-1518313645_thumb.jpg

post-372-0-86936900-1518313662_thumb.jpg

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