Recommended BBC Model B upgrades

discuss both original and modern hardware for the bbc micro/electron
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Re: Recommended BBC Model B upgrades

Post by Coeus » Wed Sep 09, 2020 7:49 pm

English Invader wrote:
Wed Sep 09, 2020 5:55 pm
May I ask why a Gotek would be any more problematic than a regular floppy drive? My understanding is that the file management software/firmware for the Gotek is at the device's end and that all the BBC will see is a set of instructions that appear to be from a 5.25" floppy and act accordingly.
I am not sure it is the GOTEK in particular that is the problem. Rather, people have found interactions between two DFS-like filing systems in the past.

There is a dilemma here because some software hard-codes things like '*DISC' so a filing system that is intended to both behave like, and replace, DFS might choose to respond to *DISC by selecting itself. When one needs to access both real DFS and the card filing system that isn't what is wanted, though. Furthermore it depends on the order of the two ROMS.

The answer is for the card filing system to have an option as to whether it masquerades as DFS or not - I think I remember this being added to MMFS and other may have it too.

There is also the RAM consumption issue. Filing systems would normally have their directory/sector caches in shared workspace and would therefore flush those when switching filing system. That usually accounts for most of the filing system RAM usage but each would probably also claim a page of private workspace. The more of them you have in the machine, the more memory is consumed.

Of course, if you use a card filing system like MMFS 99% of the time and a real floppy disc just occasionally, the answer is to have the DFS ROM on the SD card and load it into sideways RAM on the odd occasion you need to access floppy discs. If your use of more 50/50 then that may not be so convenient but things do load into RAM pretty quick.

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Re: Recommended BBC Model B upgrades

Post by danielj » Wed Sep 09, 2020 7:59 pm

Apart from the slight compatibility issues, the other drawback of the MMC systems is they occupy the user port, so you can't play with anything that attaches to that at the same time (e.g. Mouse etc).

Speed-wise, gotek is as fast as a floppy. It's barely a big issue on a 32k machine :) tape on the other hand is always masochistic :D

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Re: Recommended BBC Model B upgrades

Post by 1024MAK » Wed Sep 09, 2020 8:06 pm

Or to put it more simply, the floppy disk system (with either a real floppy disk drive or a Gotek) needs a ROM chip (* but see below) to provide a filing system. This will require some of the main RAM as workspace.

The MMC/SD system will also need a filing system. Again on ROM. And again, it will require some of the main RAM as workspace.
Some of the MMC/SD systems are based partly on the existing Acorn DFS. And for simplicity and compatibility, they use the same commands.

So you have two problems, the first is that having two filing systems will use up more of main RAM. Unfortunately this is likely to mean that many games will not not work.

Depending on the physical order (and therefore the logical order) the ROMs are placed in the system, one filing system ROM may grab a command you intended for the other filing system.

A lot very much depends on which filing system you use for the MMC/SD system.

* Note: if you have sideways RAM, the image of the ROM can be loaded into RAM when required.

Mark

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Re: Recommended BBC Model B upgrades

Post by 1024MAK » Wed Sep 09, 2020 8:20 pm

danielj wrote:
Wed Sep 09, 2020 7:59 pm
Apart from the slight compatibility issues, the other drawback of the MMC systems is they occupy the user port, so you can't play with anything that attaches to that at the same time (e.g. Mouse etc).

Speed-wise, gotek is as fast as a floppy. It's barely a big issue on a 32k machine :) tape on the other hand is always masochistic :D
Hi Daniel

One of the drawbacks of the Acorn tape system on the Beebs, is that the data rate is fixed at only one of two rates. So there is no opportunity to have a much faster data rate. If using a PC as a digital cassette deck, on other some other makes of 1980s home computers, the data rate can be much, much faster. Think UPURS for the nearest thing to this on a Beeb.

Speaking of which, English Invader should have a look at UPURS as well.

How many people actually use the user port as a user port? If English Invader has no plans to use the user port for anything else, it’s not a problem.

The downside of a real floppy drive or a Gotek is that the Beeb needs a disk drive controller chip or module (and supporting components). No problem if this is all already fitted. But it’s an extra expense if not.

Mark

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Re: Recommended BBC Model B upgrades

Post by danielj » Wed Sep 09, 2020 8:26 pm

I wasn't referring particularly to EnglishInvader's questions, actually more to the points made to Jason (who does have a disk interface).

If you don't have a disc interface already then clearly the MMC system is always a viable and sensible option if you don't want to spend more than you have to.

d.

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Re: Recommended BBC Model B upgrades

Post by dsdf323 » Wed Sep 09, 2020 8:40 pm

Wheel_nut wrote:
Wed Sep 09, 2020 12:14 pm

See this thread which covers my deliberations in selecting ROMs. viewtopic.php?f=2&t=18845&p=262961#p262961

You may also have discovered that there is a quirk im Mark's rework instructions which brings the ROMs in in a strange order ... but that is a different discussion and is in a different thread.
Oh perfect, thanks Robin - I've been pondering asking the forum which are the best set, especially as I grew up Amstrad so all the utilities, etc. on the Beeb are new to me.
Brett.

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Re: Recommended BBC Model B upgrades

Post by BigEd » Wed Sep 09, 2020 8:45 pm

AIUI, MMFS with sideways RAM can keep PAGE down at E00, so you get the benefit of a (fast) solid state floppy system without the disadvantage of losing a lot of RAM to workspace. (You do indeed lose the User Port, or some pins of it, at least on an unmodified Beeb.)

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Re: Recommended BBC Model B upgrades

Post by Wheel_nut » Wed Sep 09, 2020 8:50 pm

danielj wrote:
Wed Sep 09, 2020 7:59 pm
Apart from the slight compatibility issues, the other drawback of the MMC systems is they occupy the user port, so you can't play with anything that attaches to that at the same time (e.g. Mouse etc).
Don't forget that Hoglet67 has also released P/MMFS which runs the adapter on the Printer Port, leaving the User Port free for other devices like a Mouse or EPROM Programmer. Although it is slower than the User Port version, it is still an order of magnitude faster than a Floppy Disk (or Gotek).

Spoiled for choice or what! 8)
#1 BBC Model B Issue 7 + 1770 DFS + Dual TEAC Floppy
#2 BBC Model B Issue 7 + 8271 DFS + Dual Floppy + Speech
#3 BBC Model B Issue 7 + 8271 DFS + Cumana Single Floppy + PiTubeDirect on KenLowe's Tube Level Shifter

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Re: Recommended BBC Model B upgrades

Post by danielj » Wed Sep 09, 2020 9:15 pm

BigEd wrote:
Wed Sep 09, 2020 8:45 pm
AIUI, MMFS with sideways RAM can keep PAGE down at E00, so you get the benefit of a (fast) solid state floppy system without the disadvantage of losing a lot of RAM to workspace. (You do indeed lose the User Port, or some pins of it, at least on an unmodified Beeb.)
Ah, that reminds me. Best Model B upgrade: Master 128 ;) :D PAGE at &E00 for everything! Hooray! :)

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1024MAK
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Re: Recommended BBC Model B upgrades

Post by 1024MAK » Wed Sep 09, 2020 10:01 pm

danielj wrote:
Wed Sep 09, 2020 9:15 pm
BigEd wrote:
Wed Sep 09, 2020 8:45 pm
AIUI, MMFS with sideways RAM can keep PAGE down at E00, so you get the benefit of a (fast) solid state floppy system without the disadvantage of losing a lot of RAM to workspace. (You do indeed lose the User Port, or some pins of it, at least on an unmodified Beeb.)
Ah, that reminds me. Best Model B upgrade: Master 128 ;) :D PAGE at &E00 for everything! Hooray! :)
And it comes with ADFS as standard :lol:
As well as DFS
Mark

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Re: Recommended BBC Model B upgrades

Post by rmbrowngr » Thu Sep 10, 2020 6:43 am

I’ve tried both Gotek and MMFS SD card solutions and I do prefer using the Gotek for ease of use with disk images e.g. no need to mess around with mmb file on the SD card containing all the disk images. Speed performance is just fine with Gotek and gives a nice retro experience.

Regarding loading DFS or ADFS into sideways RAM, I’ve been thinking it would be nice to have a solution which could load them in SW RAM upon boot, but I have no idea how to make such a solution.
Richard B
Acorn Electrons issue 4 and 6, MRB, Plus 1, AP6, AP5, Pegasus 400, BeebSCSI, Gotek, Raspberry Pi, GoSDC MBE.
BBC B+ 64K (128K upgraded) with Duel OS, Raspberry Pi and Gotek.

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Re: Recommended BBC Model B upgrades

Post by English Invader » Thu Sep 10, 2020 8:03 am

I was just looking up sideways RAM and found this video that aimed to have MMC and a floppy drive in harmony together:
https://www.youtube.com/watch?v=IcdEDBelh1w

The message seems to be that it can be done but the SW RAM is not easy to install. The video doesn't mention any trade off in software compatibility but I wonder if there is some.

As you may have surmised from my previous posts in the thread, I've purchased both an MMC and a Gotek and was planning to use both of them in tandem but it seems like I'll just have to give both of them a go separately and decide which one works out best. I'm not ruling out SW RAM but I want to see if there are tangible benefits from both devices to make it worth my while first.

I'm enjoying the MMC but the main drawback is that it appears to be Windows dependant for file transfer and I run Linux on my main system. It means I'll have to dig out one of my old XP laptops every time I want to add a few new games. The Gotek will allow me to transfer files more quickly and conveniently.

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Re: Recommended BBC Model B upgrades

Post by BigEd » Thu Sep 10, 2020 8:15 am

You don't need Windows if you're using and MMB file and MMFS - there's a nice set of command line tools and now there's a GUI tool too.
MMBExplorer released!
MMB/SSD Utils in perl

And about sideways RAM, from upthread:
flaxcottage wrote:
Tue Sep 08, 2020 9:19 am
The BooBip SWR and EEPROM boards are a 'must' for a Beeb.

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Re: Recommended BBC Model B upgrades

Post by English Invader » Thu Sep 10, 2020 8:37 am

BigEd wrote:
Thu Sep 10, 2020 8:15 am
You don't need Windows if you're using and MMB file and MMFS - there's a nice set of command line tools and now there's a GUI tool too.
MMBExplorer released!
MMB/SSD Utils in perl

And about sideways RAM, from upthread:
flaxcottage wrote:
Tue Sep 08, 2020 9:19 am
The BooBip SWR and EEPROM boards are a 'must' for a Beeb.
Thanks. Those solutions look like real game changers 8) .

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Re: Recommended BBC Model B upgrades

Post by tricky » Thu Sep 10, 2020 9:16 am

I'm not saying that it would, if anything, I would expect it to be less problematic.
I'm saying the having both an MMC device and floppy device can be problematic, not because of the device, but because you have two filing system ROMs and each is likely to want memory, which will push up PAGE and can make some programs not work.
You can make one use sideways RAM if you have it wich will make it no worse than a single ROM except possible interactions (MMC ROMs have ways to avoid conflicts that mostly work).
If you have sideways RAM, I would choose a primary filing system and have a ROM image that you can load into SWRAM to use the other as and when required.

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Re: Recommended BBC Model B upgrades

Post by JasonStonier » Thu Sep 10, 2020 9:18 am

English Invader wrote:
Thu Sep 10, 2020 8:37 am
BigEd wrote:
Thu Sep 10, 2020 8:15 am
You don't need Windows if you're using and MMB file and MMFS - there's a nice set of command line tools and now there's a GUI tool too.
MMBExplorer released!
MMB/SSD Utils in perl
Thanks. Those solutions look like real game changers 8) .
I was thinking exactly the same thing myself. I find PCs are like air conditioning - they work perfectly until you open windows. Although I just dug out an old parallel port EEPROM programmer from the loft, which only has software for Windows XP so I might need to break out an old PC and go back to the stone age.

Anyway, jokes aside - any reason I can't put the 1770 DFS and the TurboSPI ROMs in a ROM switcher so a Gotek and the MMB board can co-exist?

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Re: Recommended BBC Model B upgrades

Post by JasonStonier » Thu Sep 10, 2020 9:25 am

First of the modifications done, and I have a Beeb that starts up properly.

Rather than re-capping the power supply, I bought a new one from RS - Meanwell RPT-60A is pin compatible with the Beeb, has the same footprint as a credit card, and delivers up to 60W so it's a great replacement for £12.

I've also off-boarded the keyboard by splitting an old parallel port cable in half and soldering a couple of 17-pin inline headers to the appropriate cores. The keyboard is now "unplug-able" for when I build the tower case.

No beebs were harmed in the making of this modification, and it means that I'm going to have a spare case which is in good condition if anyone needs one - even the "ashtray" hasn't been pulled out, which is pretty unusual.

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Re: Recommended BBC Model B upgrades

Post by flaxcottage » Thu Sep 10, 2020 9:27 am

A 1770 DFS and MMFS can co-exist OK in the one machine. I have several doing just that. :D

Either may be disabled by poking 0 into the ROM table at &2Ax, where x is the ROM number. The ROM order and hence the boot filing system precedence will be determined by the physical position of the ROMs in the BBC.

MMFS and Econet, though, cannot co-exist. :(
- John

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Re: Recommended BBC Model B upgrades

Post by cmorley » Thu Sep 10, 2020 9:55 am

flaxcottage wrote:
Tue Sep 08, 2020 9:19 am
The BooBip SWR and EEPROM boards are a 'must' for a Beeb.
For newer forum members' information I make these. There is a sales thread on this forum for them.. it has probably sunk a bit so I could bump it.

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Re: Recommended BBC Model B upgrades

Post by JasonStonier » Thu Sep 10, 2020 11:51 am

I'm going to buy a SWR/EPROM board from you...when the current flurry of spending has been forgotten by the boss.

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Re: Recommended BBC Model B upgrades

Post by JasonStonier » Thu Sep 10, 2020 11:54 am

Does anyone have any advice on refurbing a keyboard - it all works fine, but the keys are harder to press and a bit stickier than I remember from BITD. Is it just a question of popping off every keycap and cleaning the contacts and springs? If so, any recommended cleaner, or just generic spray contact cleaner? Thanks.

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