Fast IEC ?

TomXP411 · Post by **TomXP411** » Fri Jan 15, 2021 2:27 am

3 hours ago, rje said:

Oooooooh.... how about SD2IEC with a Wifi SD card? ?

Why? The user port will be the same speed, since it's all software controlled. So you might as well just bit shift through the User port and run an external ESP32.

rje · Post by **rje** » Fri Jan 15, 2021 3:48 am

1 hour ago, TomXP411 said:

Why? The user port will be the same speed, since it's all software controlled. So you might as well just bit shift through the User port and run an external ESP32.

Why use a Wifi SD card? I might be wrong, but it sounds like it grants the X16 a file system that's network-accessible.

Imagine the fun, there. One of my Rpi Zero W's can monitor the SD card's file system, proxying requests to the web in an astonishingly slow -- but fun -- fashion. Network access, through a proxy, with none of the dangers. Holy crap, my Traveller game won't need to store the galactic map -- it's all on the web, and now I know how to get at the web from the X16. That's a game changer.

More practically, it avoids the physical swap cycle of transferring files to and from the X16 via the SD card.

Plus -- and yes, this is a plus -- then people like me won't have to make all the mistakes of learning to properly shift bits. I would use up a lot of aspirin. Although I guess I know ROL and ROR... but still. It's not that I don't find designing hardware and writing assembly language sexy -- I'm a big enough nerd to like it. It's just that I'm no good at it. There. I said it. In my hobby hours, I'd rather write Perl than assembly. And I'm friggin' good at it, too... Perl ain't just a text mangler and process controller... it can pack binary records like no one's business. It's just not C-fast and is a memory hog. That's what you get when C and Awk have a love child.

But yes, I have no problems with other hardware solutions.

In fact, I prefer MANY options, so that I can pick my price point based on my need of the moment. I also mused on the venerable IEC (with an appropriate bursty mode), as well as the slightly less venerable I2C.

BruceMcF · Post by **BruceMcF** » Fri Jan 15, 2021 4:41 am

If it's to communicate with a PC, I don't understand the "SD2" part ... a USB to parallel converter plus a parallel to IEC cable would do. That would come out to a long way less than $70.

And if it's to sneaker net to the PC, then a second SD card slot on an expansion card could be done that was substantially cheaper than an SD2IEC.

TomXP411 · Post by **TomXP411** » Fri Jan 15, 2021 8:59 am

4 hours ago, rje said:

Why use a Wifi SD card? I might be wrong, but it sounds like it grants the X16 a file system that's network-accessible.

Imagine the fun, there. One of my Rpi Zero W's can monitor the SD card's file system, proxying requests to the web in an astonishingly slow -- but fun -- fashion. Network access, through a proxy, with none of the dangers. Holy crap, my Traveller game won't need to store the galactic map -- it's all on the web, and now I know how to get at the web from the X16. That's a game changer

Why use an IEC based device at all? If the SD card can act as a file server (which I doubt), then you can just install one in the Commander. And if it can't... the SD2IEC is always going to be slower than either the internal port or a parallel connected device.

TomXP411 · Post by **TomXP411** » Fri Jan 15, 2021 9:14 am

11 hours ago, Lorin Millsap said:

Not needed as there is an integrated SD card which is orders of magnitude faster than SD2IEC. No sense in implementing a fast loader for legacy devices when firstly it can be done in software for the cases that need it, which realistically will be rarely.

It's not, really. The FAT32 driver is hampered by running on the 6502, and it shows. I did some testing today, and raw file reads from SD run at around 9KB/s. That's much slower than what the hardware should be capable of, so I'm going to assume it's just due to the sheer amount of code needed to read a file stream from a FAT32 volume.

I have clocked my SD2IEC at 6KB/s - and that's connected to a 1MHz Commodore 64. Running an SD2IEC at 8MHz, instead of 1MHz, you could expect speeds of 40-50Mhz. I'm not sure existing SD2IEC devices could actually do this, since they're based on slower AVR microcontrollers, but a device with a faster ARM chip, like the Teensy 3.5, is certainly capable of those kinds of speeds.

Fnord42 · Post by **Fnord42** » Fri Jan 15, 2021 1:06 pm

14 hours ago, m00dawg said:

The idea seems to be, given the SD card is at the back of the computer, that one won't be removing it from the X16 all that often. But for active development, that could happen _a ton_ and likewise for sharing content made (you know like tracker files, demos, etc.) one will have to yank the card.

It should not be too hard to build an extension cable using two of those sd-to-microsd adapters that everybody has a ton of and some ribbon cable, I guess. That way, you can at least have the card at a more accessible location.

Of course, any solution that eliminates the need for physically handling storage media would be much preferable to this.

Lorin Millsap · Post by **Lorin Millsap** » Fri Jan 15, 2021 1:28 pm

It’s not like it’s large or heavy. Just reach back and pop it out.

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Fnord42 · Post by **Fnord42** » Fri Jan 15, 2021 1:39 pm

Maybe it's just one of those things that you imagine to be terribly annoying, but then get used to quickly. But apparently it seems to be an issue for some people.

However, it will be fun to see (and/or make) the wlan-based solutions that will inevitably turn up sooner or later.

rje · Post by **rje** » Fri Jan 15, 2021 2:59 pm

Swapping SD cards is not really the same as swapping floppies. I mean, the human side of the action is the same, but SD cards seem less happy about it. Maybe it depends on the quality of the SD card, but it seems less happy than cartridge swapping, which I assume is designed around heavy plug-unplug use. SD cards are designed to stay where they're put, with a minimum of swappage.

Lorin Millsap · Post by **Lorin Millsap** » Fri Jan 15, 2021 3:16 pm

Swapping SD cards is not really the same as swapping floppies. I mean, the human side of the action is the same, but SD cards seem less happy about it. Maybe it depends on the quality of the SD card, but it seems less happy than cartridge swapping, which I assume is designed around heavy plug-unplug use. SD cards are designed to stay where they're put, with a minimum of swappage.

Valid point to a large degree. Less of an issue here if the system always closes its files, but I can see wear being an issue. To minimize swapping you will have serial. And if you do all your testing in the emulator you will not need to swap cards as much.

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