SD-Cart JR: An MMC/SD card reader cartridge

[ckreling]

Thanks! I have not heard about enough people using it with success yet, and I don't know how the boot ROM interacts with JR-IDE. i.e Which one has boot priority? Which one will be the first hard drive on the system? The problem is that it's not easy to update an OTP EPROM soldered to the board direclty... The reason it is not in a socket is that it does not fit in a cartridge... Oh! But it just occurred to me that I could design an enclosure with an opening in front of the chip and then sell the board with a boot rom in a socket! Would you be interested?

Yes - that would be something I would purchase! Thanks

[cyb2600]

Are you using the most recent release of the boot ROM? If fdisk does not see a hard drive, it may mean that the int13 handler was not installed. The int13 handler will not be installed if there is an error accessing the card at boot time. Did you try other cards?

I hope I'll be able to get my hands on a JX some day!

I think I’m running the latest but I’ll double check. In JR mode I get a message at boot that the handler was installed. In JX mode I don’t. It doesn’t work in either mode unless I install the driver after boot, but even with the driver installed, fdisk doesn’t find the disk.

The biggest frustration is that in JX mode it only boots KDOS 2.11, so the hard drive has to be formatted FAT12 for it to work. Besides limiting the size of the partition it means you can’t just pop the SD card into your computer and transfer files over. There must be some way to trick it into booting “regular” DOS so I can use 5.0 or at least 3.3

[frax]

Out of stock? Any more coming soon?

[Tempest]

So if I'm understanding this right, the SD-Cart can basically act as a SD card powered Hard Drive? If one were to use this in conjunction with a 640K RAM sidecar, could you replace the JrIDE? The only missing function would be the RTC. I ask because my JrIDE is being flaky.

[raphnet]

Out of stock? Any more coming soon?

Yes, very soon in 1 to 3 weeks (waiting for parts...)

So if I'm understanding this right, the SD-Cart can basically act as a SD card powered Hard Drive? If one were to use this in conjunction with a 640K RAM sidecar, could you replace the JrIDE? The only missing function would be the RTC. I ask because my JrIDE is being flaky.

Yes, with the boot rom installed you can use it as a hard drive. But it will be much slower than the jr-IDE.

Yes - that would be something I would purchase! Thanks

Thanks! The new batch that is coming will have a boot rom (in socket) option. I will also solder it directly to the board if requested to.

I tested the boot ROM on my jr-IDE system: the SD-Cart jr boot ROM has priority. Boots to jrIDE BIOS screen as usual then directly displays SD-CART jr BIOS screen and boots to the cartridge. It apprears that the jrIDE hard drive is not recognized as it is not assigned a drive letter.

Hmm.. That's not what I hoped would happen. I wanted the SD-Cart JR to be C:, and the jrIDE hard drive D:... Anyway, I sold enough to finally buy myself a jr-IDE, and it has just arrived (I will have more than 256kB of RAM at last!). So I should figure this out and release a new boot ROM soon.

[Jiidari]

How does the SD-Cart speed compare to a floppy drive? The simplicity and non-invasive design seem like really nice benefits over an IDE, plus it's another way to move files between a PCjr and a modern PC. Those advantages seem like they'd make this a great starting point, even if it is a little slow.

[Brutman]

It is much faster than a floppy drive. A floppy drive can transfer around 11KB/sec at best. SDCart Jr was hitting at least 40KB/sec on reads and writes.

With the boot ROM it is a nice, portable hard drive solution for a PCjr. Not as fast as a jrIDE, but more than functional. Unless you are running a busy transactional database on your machine you will be fine. ;-0


Mike

[raphnet]

Yes - that would be something I would purchase! Thanks

Out of stock? Any more coming soon?

SD-Cart JR is finally back in stock and can now also be ordered with a boot ROM:
https://www.raphnet-tech.com/products/s ... /index.php

The new version of the boot ROM now works with other hard drives (tested only with jr-IDE). An option menu has been added to the boot screen, to allow different scenarios (Install SD-Cart JR as first drive, last drive, sole drive...).

[jscrow]

The new version of the boot rom sounds great! Are you going to make available for download on the project page?

[raphnet]

The new version of the boot rom sounds great! Are you going to make available for download on the project page?

Yes, first there are some things I want to add to the driver and surrounding tools, then I'll release a new package.