Status: building v2 boards, expecting to send the first few out June/July 2019
I've finally figured out a design I'm happy with for this -- posting here to see if anyone else would be interested in one.
This will be a board that plugs in to the four ROM sockets on an A3000, and act like a DualOS/MultiOS board, plus let you flash new versions of RISC OS (or old versions... so you could have a machine that'll boot up with Arthur, RO2, RO3, the test ROMs, your own RO build...) over USB without having to open the case.
- 16MB of flash memory, so you can store 4-8 different OS ROMs at once (4 x 4MB, 8 x 2MB, 16 x 1MB, or any combination).
- In-system programmability -- you'll be able to connect your Arc up to a laptop via USB, and update the OS images while it's running (or powered down)
- SYS "OS_UpdateMEMC", 64, 64 support, even under RISC OS 3, for some extra speed
- Support for all 4-ROM machines (A3000, A3xx, A4xx, A5xx, A5000 with adapter).
- The ability to make 4MB of flash visible to the machine by wiring in the A21 line, so you can fit more stuff in your RISC OS build
- Not enough room for this one: MAYBE a fast USB serial port for off-machine communications (HostFS maybe?) using the extra address space, if I can fit this into the CPLD
Cost will be about $100 (£78) assembled including shipping worldwide; a bit less if you're in the USA. Originally I was hoping to offer a kitset version, except the board has several hard-to-solder BGA chips, and the work of packing up kitsets is about the same as assembling the board, so this isn't going to happen unless you live in the SF Bay Area and want to come over and help me assemble your board.
Caveat of course here is that I might not actually finish the project, but if I do, it'll be more or less as above
UPDATE: Keeping track of who's interested (from replies to this thread) - I'll confirm all this before actually ordering anything; this is just to give me an idea of who to talk to when I do have something working.
- IanS - one or more
- hubersn - 1 of the A310 type (has carrier board), 3 x A3000 (most important), 2 x A5000 type, 2-5 x Risc PC.
- paulv - one
- trixter - one (assembled)
- lcww1 - one
- JonC - 1 x A3000, 1 x A3020, 2 x A5000 (1's an Alpha), 1 x A440, 2 x A310, 1 x RISCPC
- 1024MAK - one or more for A5000, A30x0, A7000/Risc PC.
- Cutter - 1 x A3000
- markrwj - 1 x A3000
- Nutter - 1 x A3000
- sirbod - 1 x A305 (later: A440/1, A4000 and A5000)
- steve3000 - 1 x A540
- Sniffler - 1 x A3000, 1 x A5000
- stevebubs - 1 x 4-ROM, 1 x RISC PC
- Kazzie - 1 x A420/1
- anightin - 1 x RPC600, 1 x RPC700