Cheap SD/MMC Readers

[melchett]

Looks good - thank you

[danielj]

This post is work in progress so please PM me if you spot any errors or omissions.

Probably worth noting that there's a distinct difference between using the gotek as a floppy emulator (which is its primary function) and using it as an mmc-alike. DUTILS etc are really only relevant for the later, when using Tricky's menu (which is self contained, so it doesn't really ever come to the fore). If using it as a straight floppy emulator, you can store your images in directories on the USB stick, and it supports protected/double sided disk images etc.

[Wheel_nut]

This post is work in progress so please PM me if you spot any errors or omissions.

Probably worth noting that there's a distinct difference between using the gotek as a floppy emulator (which is its primary function) and using it as an mmc-alike. DUTILS etc are really only relevant for the later, when using Tricky's menu (which is self contained, so it doesn't really ever come to the fore). If using it as a straight floppy emulator, you can store your images in directories on the USB stick, and it supports protected/double sided disk images etc.

Hi Daniel,

I am not sure that I understand your point. The purpose of my table is in the Context of the Thread header which is "Cheap SD/MMC Readers". I agree with you that the Gotek as a Floppy Drive emulator is capable of much more than is facilitated by connection to a 8271/ 177n Disk Interface and driven by DFS/ ADFS.

Tricky's *DIN and *DBOOT Utilities make the Gotek much more usable as a File repository and (IMHO) it really could do with a *DCAT when using it outside Tricky's Menu environment.

I am not aware of any mechanism for switching/ reading/ writing data into Folders (Directories in the DOS Context) when accessing disk images on a Gotek. Yes, an SSD may contain a DFS prefix subdirectory but the *DDIR selectable (DOS) Folder structure on the USB Stick/ SD Card is only accessable on MMFSv2. ... unless I am missing something and I would love to know how to do this.

Please let me know if there is something specific that you would like me to amend i the post. I use all three forms of storage devices on my Beebs so have no wish to discredit any of them.

Robin

[danielj]

Oops, sorry Robin, I meant to stick that in a PM! - I think I was really just pondering that I don't consider a gotek to really be an MMC system (unless you decide to use it with Tricky's menu) - it's sort of like comparing apples/oranges in my mind. So some things that are perceptibly drawbacks when comparing it in that context, aren't in actual use as you don't tend to use it like that. If that makes sense?

d.

[Wheel_nut]

Hi Daniel,

Yes, I fully agree that the Gotek is not a directly comparable device but it is one of the most common modern alternatives to the Floppy Disk legacy storage that existed when the Beeb was conceived.

The discussion of which storage device to use comes up frequently in these fora and my intention was to try and illustrate the pros and cons of each of the three alternatives.

I am happy to edit the post or the table if you consider it to be misleading or inaccurate.

I have no problem with discussing this openly in this thread. - Robin

Edit: p.s. Even though they are completely different devices, with the elimination of the .MMB capsule, MMFSv2 is now functionally overlapping into the Gotek and Floppy Disk Drive territory - R

[Wheel_nut]

I am posting my document detailing my experience of setting up and using MMFSv2 here in response to questions raised in several threads on this board.

Mark, I have posted it here because this is a Sticky thread and I can easily point users to it. If there is somewhere more appropriate to place it, please feel free to move it or if it breaks forum protocol, please delete it.

I also attempted to attach a zip if the SD Card that I use, containing the STH and Tricky Games libraries but it is too large.

Robin

[tricky]

Your table could do with a few updates and possibly adding beebscsi or the 1mhz pi version.

Goteks can be fitted internally or I believed under the beeb for the newer smaller ones.

I thought MMFS supported multiple .mmb files chained together.

smartspi supports multiple .mmb files that it can swap between and has the simplicity of one ROM fits all. BUT does have a write incompatibility with a couple of very old small cards.

You can get my menu and disc images for all three solutions from the top of its thread viewtopic.php?p=221136#p221136

[Wheel_nut]

Hi Tricky, Yes, I agree that the table I posted in 2021 could do with updating to include developments since then but having no experience of beebscsi or the 1mhz Pi version, I am not best placed to do this.

I have considered updating the table to show Dave's development of MMFS to cope with > 511 Disks but would also have to update the developments with Gotek technology which I have not dabbled with. Also, I should apologise to Duikkie for not including SmartSPI in the Table

Thank you for posting the linky to your repository. I still believe that it would be beneficial to have a Sticky with links to these repositories which too quickly disappear down the list (pages) of these Boards.

Keep up the good work in supporting all three platforms. - Robin

[MolMagMan]

I am posting my document detailing my experience of setting up and using MMFSv2 here in response to questions raised in several threads on this board.

Mark, I have posted it here because this is a Sticky thread and I can easily point users to it. If there is somewhere more appropriate to place it, please feel free to move it or if it breaks forum protocol, please delete it.

I also attempted to attach a zip if the SD Card that I use, containing the STH and Tricky Games libraries but it is too large.

Robin

This is brilliant Robin. Exactly what I was looking for!

[fizgog]

Just come across this site selling a Master SD Cartridge

http://ramtop-retro.uk/mastersd.html

Does anyone have one and is it any good for use with the Master?

[danielj]

Does anyone have one and is it any good for use with the Master?

For the Master, as it has a built in disc interface, the most compatible and ultimately easiest thing to use is a gotek floppy emulator with the flashfloppy firmware installed on it. You can get a very basic gotek and DIY is for probably around £30 or a bit less, or get them ready flashed with OLED display and rotary encoder for about £40: https://www.ebay.co.uk/itm/125672833445 or with all the cables for the beeb (basically a power cable and straight through ribbon cable) for about £70 if retroclinic is currently doing them. You can just use a PC floppy cable (use the connectors before the twist) and get 5V from wherever you like to power the gotek - doesn't need to be BBC or Master specific.

The benefit of going this route is that you're using the native disk systems, and so far as the computer is concerned it's using a normal floppy drive. You just drop ssd or dsd or adfs images straight onto a USB stick and you're good to go.

[Wheel_nut]

I have updated the MMFSv2 v MMFSv1 v Gotek comparison table on Page 1 of this thread to show further developments to MMFSv2 ans MMFSv1 since the Table was published here.

- Robin

[electron_plus40]

I decided to try and make my own SD reader on the cheap, with encouragement from Adrian's Digital Basement - BBC Master mods and improvements.

I picked up a "Micro SD TF Memory Card Reader Module with SPI interface For Arduino" (multiple sellers) from ebay for less than US$1. A pack of 6 20 pin ribbon cables for US$9 and used some dupont wires for US$7 (120 pcs, I used 7 male to female, and only for testing, won't be needed for the final build.)

Behold, my franken-SD reader. It does work with Master MMFSv1 though. I did flash an EPROM with that, but those I had already, so technically free.

The pinout I used is based on the github MMFS page plus VCC which isn't specifically called out there, but the linked archive.org page (for mmbeeb) does show it:

SD Board <> User Port

CS -> 19
SCK -> 2 and 8
MOSI -> 6
MISO -> 4
VCC -> 1
GND -> 15

I'll probably just cut one of the 20 pin ribbon cables in half (or less) and solder that directly on to the SD reader and stick the whole thing to the underside of the M128.

[tricky]

Nice, I made plenty worse in the early days.

[danielj]

I decided to try and make my own SD reader on the cheap, with encouragement from Adrian's Digital Basement - BBC Master mods and improvements.

Excellent! Saved many £ and also the satisfaction of having done it yourself!

[DaveLecky]

Hi Electron Plus40,

When you get to work on your electron/plus1 you can try this neat trick…on the Printer port.

IMG_3374.jpeg (59.94 KiB) Viewed 2157 times

Dave

[electron_plus40]

Hi Electron Plus40,

When you get to work on your electron/plus1 you can try this neat trick…on the Printer port.

This is definitely happening!

[DaveLecky]

Here is the link I used for info to achieve this

viewtopic.php?p=163755#p163755

Dave

[JonnoW]

Has anyone else noticed that Elite appears to be fully compatible with SmartSPI, but suffers from Bad command errors and crashes using even the most recent versions of MMFS? Is this something that is easily solved? If so, how?
Thanks

[hoglet]

Has anyone else noticed that Elite appears to be fully compatible with SmartSPI, but suffers from Bad command errors and crashes using even the most recent versions of MMFS? Is this something that is easily solved? If so, how?

This issue has been mentioned before, but no one has actually filed an issue in github for this.

I've had a quick look this afternoon, and as far as I can see, this just affects the AC3-r1-0 disk image that's included in the STH Archive BEEB.MMB file. I don't see the same issue with any other versions of BBC B Disk Elite, for example, both the versions linked here work fine:
https://www.bbcelite.com/disc/releases.html

That AC3-r1-0 disk image combines together several different games, and seems to include a custom loader (BOOT) and additional files (ELITE5 and ELITE6) that are not present on any of the other versions.

I've run it through the debugger, and what seems to be happening is the additional loader code is clobbering the disk catalog (at RAM &E00-&FFF), so that when it eventually executes the command *R.D.CODE, and MMFS looks for the file CODE in the directory D, then it can't find that in the RAM copy of the catalog, hence the Bad Command error.

The reason it works with SmartSPI is that's based on an older version of DFS, which doesn't rely on the RAM copy of the catalog quite as much. I think with early DFS versions the catalog is reloaded on every command (if the disk is not still spinning).

I suspect if you tried to use that specific disk image with Acorn's 1770 DFS 2.26 and a real floppy you might hit the same problem.

So I think this boils down a bad/buggy conversion of the game included in that BEEB.MMB file.

There is not an easy fix for this in MMFS, because it's really the game that is at fault, so all I can suggest is using one of the other disk images, use the sideways RAM version of MMFS, or stick to SmartSPI.

BTW, there is lots more information about the different versions of Elite here:
- A definitive comparison of Elite versions

I think most people who a playing Elite seriously use the Tube version, as this allows loading and saving of commanders to disk.

Dave

[JonnoW]

Thanks for the info Dave.