RCA NC1020?

Hello,
New to RiscOS. Found a RCA NC1020 which runs some form of RiscOS/NCOS.
Is there a way to “upgrade” this “relic” to RiscOS Open?
Thanks in advance!

Hi iVan,
You should try the IOMD softload ROM out.

Hi iVan

There’s a few issues with running RISC OS on NC-like devices:

• They’re ARM7500 or ARM7500FE. I don’t know how well tested the 7500 code in the IOMD port is
• They sometimes have different hardware from the A7000 or A7000+ (the canonical 7500 and 7500FE machines respectively)
• You need some way of getting the ROM images onto them. My NC has no ROMs onboard, but has a PCMCIA-like card (which isn’t true PCMCIA). Other NCs have socketed or soldered ROMs. A softload should be possible if you have enough RAM, but you need a filesystem to load the softload from.
• You may have limited RAM. RISC OS images are about 4-6MB, which is rather unfortunate if you only have 4MB RAM on the motherboard and a 4MB ROM softload.

[Point of terminology: softload means load a ROM image into RAM then reboot, using that as the new OS image rather than the physical ROMs. This means you boot twice every time you power up]

It’s possible to network boot ethernet NCs:
http://www.riscos.info/index.php/Booting_a_Network_Computer
Potentially that might be a route to running a softload. I don’t know what the RCA NC will do – many consumer versions had the telco’s own boot methods on them. Try plugging in a keyboard and pressing Alt-Alt – does that get you a config menu? Also trying powering up with shift held down – that might skip the boot process (did you post your experience as zahal on nekochan ?)

Hello,
Thanks for the replies.
I checked out the IOMD softload ROM, but can’t get to a desktop on the NC1020.
Processor is PS7500FE-QC-A, and it has a PCMCIA slot up front. Could a compact flash memory in a CF-PCMCIA adapter be used to boot this machine?
Yes, I posted my experience as zahal on nekochan. I plug keyboard, mouse and VGA monitor on the NC1020, and I get a line that reads “Acorn ResourceFS”, then I get a centered cursor followed by a rotating hourglass. After that the screen just goes blank. NC1020 has a modem and there seems no way to plug an ethernet card (unless it’s a parallel port ethernet adapter). From the info I found online, the NC1020 has 5MB RAM and 8MB ROM.
I tried today pressing R, Delete, the numbers and the * on the numeric keypad while turning it on. None of them gave me a menu or a command line boot.
Pressing Shift during startup would prevent the STB from getting to the “Acorn ResourceFS” step, and it would just cycle between video signal and no video signal to the monitor.
I will try Alt-Alt and see if any menu is displayed.

edit: I tried Alt-Alt but no menu comes up. Same boot process as described up to the blank screen.

A lot of NCs expected some form of BootP / NFS server setup. I recall having to go through a convoluted Linux server setup when doing NC dev at some point. However, some would also boot off iomega Zip drives depending on what modules were in the ROM.

Without a network card, it seems unlikely that it is waiting for a network server, but a normal RISC OS boot wasn’t always a standard feature of an NC – some were focussed solely on delivering specific content, with a RISC OS desktop as very much an optional extra.

ResourceFS is the ROM filing system, where ROM apps/resources appear. It sounds like it is probably designed to boot from there, but is waiting for some other element.

The modem card ROM was sometimes used to add extra components. It might be worth testing with/without modem card to see if that makes any difference. For example, I think the ZipFS module was on the modem card of the NCs we did dev work for/on.

alt-break can sometimes kill running processes on RISC OS, which may get you to a command prompt, depending on what state it is in. Also escape key sometimes.

I have/d two NCs, one a very early prototype running NCOS 0.1 and a Bush IBX100 STB, which was about the last gasp of the NC division under Pace. Both have PCMCIA sockets (or PCB footprints for them), but the signals to these aren’t actually PCMCIA. For one, PCMCIA has 16 bits and the ARM has a 32 bit data bus, and all 32 bits are wired to the socket. The early NC uses some 4MB EPROM chips in a PCMCIA-like card, but the wiring is different. One or two Acorn development machines supported true PCMCIA, but only for simple (4MB, 8MB) flash cards. So you won’t be able to boot from a CF card, but a parallel port Zip drive (only the 100MB version?) might work.

Any chance of some pictures? It might help us identify what’s inside.

I have a few Matrix NCs, looking for good homes.

Hello, thanks for the replies. After reading some more about similar STB’s, I found that some would load to a similar black screen and would only display the GUI after the “Internet” key was pressed. I am using a regular PS/2 PC keyboard with no “Internet” key. Is there a keyboard combination that emulates the “Internet” key present in the STB keyboards?
Is there a picture section on riscosopen where I can upload pics of the NC1020’s internals?

I don’t know what the ‘Internet’ key is – have you tried pressing Windows or Menu keys to see if that does anything?

There isn’t an uploads section, but try putting the pictures on Flickr, ImageShack, PhotoBucket or something. Anything that keeps them at full resolution is good (so we can read the numbers on the chips) – Flickr does that, not sure about the others.

The only “Internet” key I’m aware of was on the remote for the Bush Internet TV – a different device from the old RCA NCs. I think the Internet key was actually a command to the IR receiver in the TV board (not the RISC OS board) to switch its video input to the RISC OS board rather than the TV tuner. None of that is applicable to the RCA NCs.

In theory you might be able to create a RISC OS 5 build that runs on the various NCs, but I wouldn’t expect the IOMD softload to work as-is. The reason for this is that when Acorn/Pace designed the PCBs, they often used different support chips, and even when the chips were the same, interrupt routing was often different. Each board was manufactured with its own customised masked ROMs anyway, so there was no need to be software-compatible with desktop RISC OS ROMs.

If you’re lucky, you might get close to a solution by recompiling our IOMD ROM using a modified Env file that sets the “Machine” variable to some other value, (for example, “Omega” for the RCA NCs, or “Lazarus” for the Bush Internet TV) but I can’t guarantee that these still work.

Ah yes, on the STB versions the internet button (more a button than a key – it was big and rubber!) would toggle the control pin on the SCART socket so the TV switched to that input. I think that was done entirely by the IR microcontroller rather than through RISC OS. If you get any kind of display from RISC OS then this isn’t relevant.

Ben, just out of curiosity, is all the NC stuff in the public source tree? ISTR there were lots of modules called NCThis and NCThat which I don’t see. Is the NC division fork of the OS in your CVS? Obviously some were copyright other people (eg the Fresco browser). Or do you have sources to them but haven’t released them? Not that it really matters, but just interested.

Pretty much everything that is NC- or STB-speccific and not required for the desktop machines is still only in the closed source repository. There are no plans to publish those components, presumably because they are the ones (for embedded applications) that Castle feel are most likely to end up in any future commercial project. IMO.

I’ll post pic of the inside of the NC soon.
Crtrl-Break just reeboots the NC.
Alt-Break does give another screen which reads:
“Press Stop to terminate Unknown.”
And there are three options: Next Task, Cancel, Stop.
The highlighted button is “Cancel”, and I’m unable to select another option.
So far only pressing “enter” works, leaving a cursor on a black screen.

Ah, then you’re getting somewhere. I think that was the way to get into the Bush STB – it runs some stuff on boot. If you press Alt-Break, you can kill the current task by clicking Stop (or pressing Enter). Then you got dropped into an OS prompt. If you have a cursor, try Alt-Break again, or Escape. Also try switching on with Shift held down (skips the autoboot), or Shift and Keypad-* (skips autoboot and forces to a command prompt)

Once you’ve got to a prompt, try *Help and *Help Commands to get a list of the things you can do. *Desktop is always good (whatever kind of desktop environment you’ll get depends on what modules are in ROM – I have no idea). *ROMModules will give you a (rather long) list. You’ll probably want to switch to the ROM filing system – use *Resources to do that, then *Cat to list a directory, *Dir to change directory and *Type to show files

Hello,
Here is the NC1020 motherboard pic:
http://www.flickr.com/photos/toltec-tech/7669659412/in/photostream/
I have tried 4 different pointing devices, but the mouse cursor/buttons do not respond. I’ll try to find an older standard two button mouse and see if that works. I can’t toggle the “Next Task”, “Cancel”, “Stop” buttons with the keyboard either. Only the enter key works and since the selected button is “Cancel”, I’m back at the black screen.

Right, so that’s a standard-ish NC then:

• ARM7500FE processor
• SMC FDC37C669 I/O chip used only for the parallel port and maybe IR – has serial, IDE and floppy too but unused. The serial may go to the modem
• 2x mask ROMs (probably on a 16 bit bus)
• 4x DRAM chips (2 each of different sizes) – I’ll believe you if you say they’re 5MB
• Chrontel analogue video generator
• Rockwell modem chip
• Socketed EPROM for the modem firmware
• I think that’s Acorn’s 32 bit not-really-PCMCIA socket, but I can’t be sure – could be genuine PCMCIA

Have you tried swapping around keyboard and mouse? I don’t know if the sockets are specific to each one. You are using a genuine PS/2 mouse and not a USB one in an adaptor? (the passive adaptors only work for mice designed to know about them).

Your biggest problem is going to be lack of RAM. You might get up to a dizzying 8MB if you desoldered the 1MB chips and replaced it with 4MB. A RISC OS 5 softload would be about 4-6MB so that would kill almost all of your remaining RAM. RISC OS is pretty efficient with RAM as it goes (the first machines had 512KB) but these days it’s a bit painful below 4MB. If you had a ROM/flash PCMCIA-like card that would allow you to have the full RAM free, but these were never manufactured in quantity.

However it’s still worth trying to get NCOS going – they can make a reasonable RISC OS machine of that era if you can get into them and attach a parallel Zip drive for storage.

Hello,
Looking at the memory chips, it seems that the ones at the bottom are dedicated to the video RAM (V53C16258HK50 HIGH PERFORMANCE 256K X 16 EDO PAGE MODE CMOS DYNAMIC RAM). That’s 1MB video RAM.
The other two chips seem to be V53C511816502K60 which seem to be 2MB each:
General Purpose Dynamic RAM – EDO, 1024 Refresh
Number of Words=1M
Bits Per Word=16
t(acc) Max. (S)=60n
Output Config=3-State
Nom. Supp (V)=5.0
Package=SOJ
Pins=42
Military=N
Technology=CMOS

So it would appear that this NC has 4MB RAM and 1MB VRAM. It seems like the chips worth replacing are the 2MB chips (or piggybacking chips on top of those). Still haven’t been able to get past that black screen. I’ve tried genuine PS/2 pointing devices (Trackman Marble FX, Kensington Expert mouse, Kensington WebRacer…). I need to find an older two button mouse.