John Kortink (@windfallnl) 's Twitter Profile
John Kortink

@windfallnl

Musings about hobby hardware/software development (among few other things)

ID: 3387401279

linkhttp://www.zeridajh.org calendar_today22-07-2015 14:41:57

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Released the GoSDC-Atom video player and a new version of the software, bringing (among other things) full random access (woohoo). Like Atom DOS. But without the bugs.😉

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Porting LFS, the client side of zeridajh.org/software/65lin…, to the Atom (with thanks to Roland Leurs who provided a PCB that can already break out a 'BBC user port' via PL6 or 7).

Porting LFS, the client side of zeridajh.org/software/65lin…, to the Atom (with thanks to Roland Leurs who provided a PCB that can already break out a 'BBC user port' via PL6 or 7).
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GoSDC-Atom now facilitates a temporary switch to other Acorn Atom filing systems (COS it did already, new are LFS (65Link), AtoMMC and DOS). This theoretically allows files to be transferred between any two of them, GoSDC acting as the hub.

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If you had a basic Acorn Atom, and all you wanted for Christmas was 65Link (which is damned unlikely, but bear with me), then besides having to wait for another six months, it could take this shape.

If you had a basic Acorn Atom, and all you wanted for Christmas was 65Link (which is damned unlikely, but bear with me), then besides having to wait for another six months, it could take this shape.
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Did a quick port of the Acorn Atom Software Archive to LFS (65Link). A few minor menu changes, then store the files in 1115 volumes.🧐

Did a quick port of the Acorn Atom Software Archive to LFS (65Link). A few minor menu changes, then store the files in 1115 volumes.🧐
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Updated the Linux version of 65Link, so an Acorn Atom can now use a PC running Linux as a file server. Might even work from a VM (if passthrough of PCI-E I/O is supported).

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Changed all the TTL chips of an Acorn Atom to ceramic versions, and used the opportunity to get faster ones wherever it could help with overclocking. 5 MHz still fails, but 4 MHz seems rock solid (although I won't be doing any empirical research to prove that).

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Making a one-off variant of GoSDC-Atom PRO that will allow me to run my own 6502 core, at ludicrous speeds (throttling back to 1 MHz for everything still on the motherboard). The resources of the 10M50 should allow a 6502 second processor to be tacked on as well.

Making a one-off variant of GoSDC-Atom PRO that will allow me to run my own 6502 core, at ludicrous speeds (throttling back to 1 MHz for everything still on the motherboard). The resources of the 10M50 should allow a 6502 second processor to be tacked on as well.
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Building an Acorn Atom (actually two), based on a reverse-engineered PCB (thanks, mister DragonPlus). First one boots (yay). No keyboard yet. I have the 'issue 5' keyswitches but I first need to think about a keyboard plate.

Building an Acorn Atom (actually two), based on a reverse-engineered PCB (thanks, mister DragonPlus). First one boots (yay). No keyboard yet. I have the 'issue 5' keyswitches but I first need to think about a keyboard plate.
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GoSDC-Atom ULT is toddling around. With equal clocks for 6502/RAM and the motherboard, the Acorn Atom it's in can run at 7.69 MHz (14 MHz really, since my 6502 core is roughly twice the speed of a real 6502). With separate clocks, 80 MHz should be possible😀(160 MHz benchmark).

GoSDC-Atom ULT is toddling around. With equal clocks for 6502/RAM and the motherboard, the Acorn Atom it's in can run at 7.69 MHz (14 MHz really, since my 6502 core is roughly twice the speed of a real 6502). With separate clocks, 80 MHz should be possible😀(160 MHz benchmark).
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Acorn Atom running at 80 MHz, slowing down to 1 MHz for I/O (8255/6522 and video RAM).🤓For a video see youtu.be/sigzJDocEoI (there's a second one too).

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Who knew it would ever be made, The New Avengers in 4K, but it's a spectacular upgrade, compared to the shoddy DVDs that were the only thing around for 20 odd years.

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Making a one-off GoSDC ULT (BBC model B only). Same arrangement as GoSDC-Atom ULT : processor and RAM running at 80 MHz or so, and all I/O at 1 or 2 MHz (whatever the BBC's clock stretch circuitry does).

Making a one-off GoSDC ULT (BBC model B only). Same arrangement as GoSDC-Atom ULT : processor and RAM running at 80 MHz or so, and all I/O at 1 or 2 MHz (whatever the BBC's clock stretch circuitry does).
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Acorn BBC model B running at 80 MHz, slowing down to 1 or 2 MHz for I/O and framebuffer writes.🤓Who needs a second processor to accelerate their Beeb. Gotta check out some games, and see what happens.

Acorn BBC model B running at 80 MHz, slowing down to 1 or 2 MHz for I/O and framebuffer writes.🤓Who needs a second processor to accelerate their Beeb. Gotta check out some games, and see what happens.
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On an Acorn BBC running at 80 MHz, GoSDC can read files at roughly 800 KB/sec.🤪If I add a special 'port to RAM' instruction to my 6502 core, this might increase, but I have reasons to believe that the SD card has become the bottleneck here (at least in SPI mode).

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Acorn Electron said 'I can do that too !'. And so it did. A humble Elk running at 80 MHz (processor/main RAM), doing 'a bit of BASIC' ... Heh🤓

Acorn Electron said 'I can do that too !'. And so it did. A humble Elk running at 80 MHz (processor/main RAM), doing 'a bit of BASIC' ... Heh🤓
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This is what happened when I shoehorned a 6502 Second Processor into GoSDC ULT and ran both 6502s at 70 MHz (only I/O and VRAM at 1 or 2 MHz) : youtu.be/O3xGL8RrsoU. It's the ultimate kind of unplayable.🤪