Another Bush internet.tv mod thread
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Another Bush internet.tv mod thread
Thanks to Spanners who brought me some boxes of intrigue today I now have a Bush internet.tv sitting on my desk with its top off. It is an intriguing beasty which it looks like several people have performed various modifications to get a RISC OS desktop and then usually they abandon them to a dusty cupboard.
Since the mods look to be within (kinda) my abilities it seems like a fun thing to do. I don't yet have a parallel ZIP100 drive so no desktop for me but I have done some poking and investigating this evening.
Here is the little mainboard. It is very small. Can't remember how big the A7000 mainboard is but I think it is much bigger than this! There are a lot of pins on the ARM SOC that are not connected to anything.
It has RISC OS-NC (Network Computer presumably) ROM chips. Ian Jeffray says that nothing happens if you plug RO3.7 ROMs in. I also read that somewhere else that I can't find now. The person thought that might be due to the total lack of CMOS RAM circuitry, but I think that may not be true as I think most RISC OS machines drop to the supervisor prompt anyway if the CMOS RAM chip is missing. Though perhaps it is because the RO3.7 ROMS don't have the module to switch the SCART socket on.
Here is the IO chip that cunning bodgery may need to speak to:
To the right of the ROM chips is a solder point for a mysterious and quite big connector that seems to be routed to the ROM chips. No idea what this can be for.
The modem, which is part of the mainboard seems to appear to RISC OS as a podule. It has an accompanying MODEM module. This is not in the main ROM chips, but lives in this little PROM. I confirmed this by removing the PROM which made the module disappear. Perhaps, since the modem is essentially useless, an alternative module or two could be loaded here for improved functionality at power on? I haven't seen anyone investigate that.
Then finally this looks like the area where the sound components should be added. With SK1 below, which I assume is where a PS2 connector can be fitted.
Now off to stalk ebay for a reasonably priced Zip100 drive, which hopefully hasn't already click-of-deathed.
Since the mods look to be within (kinda) my abilities it seems like a fun thing to do. I don't yet have a parallel ZIP100 drive so no desktop for me but I have done some poking and investigating this evening.
Here is the little mainboard. It is very small. Can't remember how big the A7000 mainboard is but I think it is much bigger than this! There are a lot of pins on the ARM SOC that are not connected to anything.
It has RISC OS-NC (Network Computer presumably) ROM chips. Ian Jeffray says that nothing happens if you plug RO3.7 ROMs in. I also read that somewhere else that I can't find now. The person thought that might be due to the total lack of CMOS RAM circuitry, but I think that may not be true as I think most RISC OS machines drop to the supervisor prompt anyway if the CMOS RAM chip is missing. Though perhaps it is because the RO3.7 ROMS don't have the module to switch the SCART socket on.
Here is the IO chip that cunning bodgery may need to speak to:
To the right of the ROM chips is a solder point for a mysterious and quite big connector that seems to be routed to the ROM chips. No idea what this can be for.
The modem, which is part of the mainboard seems to appear to RISC OS as a podule. It has an accompanying MODEM module. This is not in the main ROM chips, but lives in this little PROM. I confirmed this by removing the PROM which made the module disappear. Perhaps, since the modem is essentially useless, an alternative module or two could be loaded here for improved functionality at power on? I haven't seen anyone investigate that.
Then finally this looks like the area where the sound components should be added. With SK1 below, which I assume is where a PS2 connector can be fitted.
Now off to stalk ebay for a reasonably priced Zip100 drive, which hopefully hasn't already click-of-deathed.
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Re: Another Bush internet.tv mod thread
I'd say that's not correct. "Most" RISC OS versions just go ga-ga without CMOS RAM - chiefly due to lack of configuration to determine which modules are inserted. Sometimes with RISC OS 3.1 you can get a "short" module list and a (non-functional) * prompt.thecellartroll wrote: ↑Thu Oct 20, 2022 10:16 pm I think that may not be true as I think most RISC OS machines drop to the supervisor prompt anyway if the CMOS RAM chip is missing.
It would be easy enough to tack on a CMOS RAM chip though - all you need is 5v, GND and the two I2C lines connected to the SoC - see if you can find anywhere the I2C is tracked out of the SoC for easier poking?
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Re: Another Bush internet.tv mod thread
The two I2C lines, if they exist, must be called something else as I can't find them on the pinout for the CL-PS7500FE. On the pinout for the IOMD on RPC they're called IICC and IICD and on the schematic I2cc and I2cd. If only a schematic existed for the A7000+!IanJeffray wrote: ↑Thu Oct 20, 2022 10:30 pm It would be easy enough to tack on a CMOS RAM chip though - all you need is 5v, GND and the two I2C lines connected to the SoC - see if you can find anywhere the I2C is tracked out of the SoC for easier poking?
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Re: Another Bush internet.tv mod thread
Ah, my investigations found this:
So I think that the CMOS RAM chip would connect to OD0 and OD1. Both of those pins are connected to vias nearby which could be soldered to.Two open drain pins which (unlike the IOP[7:0] bus) cannot be used to generate interrupts, but can be used as general purpose I/O pins, for example to communicate with a real time clock chip
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Re: Another Bush internet.tv mod thread
There must be some i2c device on the board - likely with handier chunkier places to solder to -- and it'd be interesting to find out what, since there are no other devices on the i2c bus on any other Acorn machine.thecellartroll wrote: ↑Thu Oct 20, 2022 11:41 pm Both of those pins are connected to vias nearby which could be soldered to.
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Re: Another Bush internet.tv mod thread
It looks to be a completely different design to my own Acorn Network Computer, but running the same variant of RISC OS-NC:
I got into the Supervisor prompt, and the Desktop of sorts, by removing the Ethernet podule and then pressing ESCAPE a lot:
https://www.beebmaster.co.uk/32bit/UseNC.html
I got into the Supervisor prompt, and the Desktop of sorts, by removing the Ethernet podule and then pressing ESCAPE a lot:
https://www.beebmaster.co.uk/32bit/UseNC.html
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Re: Another Bush internet.tv mod thread
The board is out of the case!IanJeffray wrote: ↑Fri Oct 21, 2022 12:07 am There must be some i2c device on the board - likely with handier chunkier places to solder to -- and it'd be interesting to find out what, since there are no other devices on the i2c bus on any other Acorn machine.
They go to this little ATMEL026, which I'm guessing is where settings for the ISP are stored.
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Re: Another Bush internet.tv mod thread
That's huge! And looks a lot less "cost reduced." I think now I know what the mystery connector on the internet.tv is though; it looks like your pcmcia connector but unpopulated.BeebMaster wrote: ↑Fri Oct 21, 2022 12:19 am It looks to be a completely different design to my own Acorn Network Computer, but running the same variant of RISC OS-NC:
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Re: Another Bush internet.tv mod thread
Could well be! I don't know what's supposed to fit there, the only thing I have ever had with a PCMCIA connector is that CD-ROM drive I tried.
It also looks like I never tried to see if it has a real-time clock.
In your pictures, I see they are named "A6000..", is that the unofficial missing number for these things?
It also looks like I never tried to see if it has a real-time clock.
In your pictures, I see they are named "A6000..", is that the unofficial missing number for these things?
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Re: Another Bush internet.tv mod thread
NC is quite a different beast to the Bush STB really. The NC is very much just a repackaged A7000.BeebMaster wrote: ↑Fri Oct 21, 2022 12:19 am It looks to be a completely different design to my own Acorn Network Computer
Acorn's NCs even had a standard podule connector -- I have an old "NC" Ethernet card in an A5000 for example.
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Re: Another Bush internet.tv mod thread
Very unofficial. I just don't like the name Bush internet.tvBeebMaster wrote: ↑Fri Oct 21, 2022 12:35 am In your pictures, I see they are named "A6000..", is that the unofficial missing number for these things?
Re: Another Bush internet.tv mod thread
Maybe it was for a potential cablecard adapter, which is common in the US for decrypting cable TV signals and is in PCMCIA format ( https://en.wikipedia.org/wiki/CableCARD )thecellartroll wrote: ↑Fri Oct 21, 2022 12:31 am I think now I know what the mystery connector on the internet.tv is though; it looks like your pcmcia connector but unpopulated.
Rgds
Stephen
Stephen
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Re: Another Bush internet.tv mod thread
I think that a good experiment would be to lift that ATMEL NVRAM chip and tack in a CMOS RAM chip and try "proper" RISC OS ROMs in it. Mainly since no-one seems to have documented trying that. It would seem to make sense that RO would flake out with totally the wrong chip connected where it is expecting to see CMOS RAM data. Do you have any spare ROMs I could borrow Ian?
Re: Another Bush internet.tv mod thread
The original NCs had a PCMCIA connector. This was to facilitate a 'smart card' slot on the front, which you used to authenticate & configure your NC. Somewhere, I have a copy of one of the versions of the smart card programming software. It typically stored your ISP dial, authentication, home page and email details. I remember programming one for Freeserve and sticking it into a NetStation.
Come to think of it, the PCMCIA hardware probably isn't a million miles away from whatever they were dreaming up for the A7000 and/or Stork.
Come to think of it, the PCMCIA hardware probably isn't a million miles away from whatever they were dreaming up for the A7000 and/or Stork.
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Re: Another Bush internet.tv mod thread
Probably. Or I can make you a set.
Don't see any need to lift the existing i2c chip out though - it's a device-addressed bus - each type of chip has a unique 7bit address, so you can just sling another thing on the bus.
If you have a scope or LA you could even see if RO is getting as far as trying to even talk to the CMOS RAM, before doing any soldering.
Another useful thing to do would be to find out where you could lash a POSTbox to the board.
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Re: Another Bush internet.tv mod thread
There is a post connector (without pins) I believe. Someone has connected a post box beforeIanJeffray wrote: ↑Fri Oct 21, 2022 6:16 pm Another useful thing to do would be to find out where you could lash a POSTbox to the board.
I do have a scope so I can certainly do some poking when I attach a CMOS RAM chip. Presumably it wont care if the crystal is missing (so I guess the clock won't run).
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Re: Another Bush internet.tv mod thread
The point was to do it without bothering soldering a CMOS RAM chip - just see if it's even doing reads.thecellartroll wrote: ↑Fri Oct 21, 2022 8:01 pm I do have a scope so I can certainly do some poking when I attach a CMOS RAM chip. Presumably it wont care if the crystal is missing (so I guess the clock won't run).
But yeah, doesn't matter if you have no xtal. Do make sure to strap the address pin, though.
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Re: Another Bush internet.tv mod thread
Looks like LK5? Has that been buzzed-out to confirm?
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Re: Another Bush internet.tv mod thread
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Re: Another Bush internet.tv mod thread
I am not familiar with "strap." Does that mean the A0 pin to ground?
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Re: Another Bush internet.tv mod thread
Yep.thecellartroll wrote: ↑Sun Oct 23, 2022 10:44 pmI am not familiar with "strap." Does that mean the A0 pin to ground?
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Re: Another Bush internet.tv mod thread
Further investigations of the board:
The distance between the pins on the ROM chips seems to be 2.5mm (measured without science). So I don't think that Ian's A3010 IDE board would fit into the ROM sockets as it looks like the A3010 sockets are further apart. Boo.
The distance between the pins on the ROM chips seems to be 2.5mm (measured without science). So I don't think that Ian's A3010 IDE board would fit into the ROM sockets as it looks like the A3010 sockets are further apart. Boo.
Re: Another Bush internet.tv mod thread
Ian already called it
Edit: also, aren't the ROMs swapped around on the Bush vs A3010?
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Re: Another Bush internet.tv mod thread
Indeed he did. More than once but I couldn't find whether anyone had actually measured.
Swapped round ROMs is not something I had even considered! How the heck to check that... *edit - looks like you are correct. When compared to the Pin1 location of the ROM chips they are the opposite way round. Baws.
Last edited by thecellartroll on Mon Oct 24, 2022 2:23 pm, edited 1 time in total.
Re: Another Bush internet.tv mod thread
Looking at your pictures, with the roms oriented so that pin 1 is upwards, there's 2208,671-11 on the left, and 2208,670-11 on the right. I'd have to check the contents to be sure, but would it be safe to assume the lower numbered IC is ROM1, the higher is ROM2, (so ROM2 left, ROM1 right)?
On the A3010, ROM1 (0296,061-02) is on the left, ROM2 (0296,062-02) on the right.
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Re: Another Bush internet.tv mod thread
You replied faster than I edited!
So that's an issue, but then there are lots of nice solder points on the adjacent PCMCIA header that would allow the fly leads (probably use a ribbon cable?) to be soldered instead as those are routed straight to the ROM sockets.
So that's an issue, but then there are lots of nice solder points on the adjacent PCMCIA header that would allow the fly leads (probably use a ribbon cable?) to be soldered instead as those are routed straight to the ROM sockets.
Re: Another Bush internet.tv mod thread
Now that would be handy, if all the pins you need are conveniently on that unpopulated connector...
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Re: Another Bush internet.tv mod thread
Now to see where all the original flying wires would connect to... BD0..BD7, ~I!3, ~B!, ~RBen, ~WBl, ~WBe
Re: Another Bush internet.tv mod thread
thecellartroll wrote: ↑Mon Oct 24, 2022 4:53 pmI can confirm that they are!
pcmcia connector pins.jpg
I was just about to say there's still 12 or so flying leads to hook up...IanJeffray wrote: ↑Mon Oct 24, 2022 5:00 pm Now to see where all the original flying wires would connect to... BD0..BD7, ~I!3, ~B!, ~RBen, ~WBl, ~WBe