Missing old/new Electron Expansions

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Elminster
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Missing old/new Electron Expansions

Post by Elminster » Wed Jun 27, 2018 11:00 am

A couple of things got me thinking on various threads about what is not about for the Electron, a dredge of previous threads really.

- With Daniel's freewifi for the serial port ... nowhere to plug it in on Electron ... and no serial port remakes
- With Beebmasters Eco hubs .... dont think there was ever a produiction econet expansion, just prototypes or homebrews.
- With Gotek or disk .... no remake of the pegasus (although still old new stock floating about) [Edit: Or the AP3, AP4 or combo AP34]
- With Viewdata board etc .... no mode 7 on Electron (tried the ROM but dont like it) .. no remake of the slogger board
- With videonula demos ... Well just need to prod RobC somemore on that one I guess

I think it would be nice to do a serial cart with a beeb serial din and a 9 pin serial connector, also an econet conneotr on it but then a Master style daughter board connection (if is was compatiable you could plug in econet or a sprom ethernet board). i.e. one board to sort all comms issues.

I should think reverse engineer pegasus would be fairly easy (well maybe not for me)

I think DaveH. alluded to something Mode 7 in the works?

Would be good after 30 years if the Electron could do everything the beeb could do (and more)

MODERATORS NOTE: See also this thread 'Proposed: "The Ultimate Electron Upgrade"' Mark
Last edited by Elminster on Thu Jul 05, 2018 3:13 pm, edited 2 times in total.

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danielj
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Re: Missing old/new Electron Expansions

Post by danielj » Wed Jun 27, 2018 11:07 am

Off you go then :D

(econet has been tried on the elk iirc, but it's horribly slow!)

Edit: sorry, that sounded a bit flippant! That wasn't really my intention...

It's quite a lot of work to do any of these things. Lots of people want lots of things. It'd be great if more people started trying to learn to do them and pile in to some of the open projects to enhance them. :) lots of support available. The more of us that learn the more things that get made!
Last edited by danielj on Wed Jun 27, 2018 11:11 am, edited 1 time in total.

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Re: Missing old/new Electron Expansions

Post by Pernod » Wed Jun 27, 2018 11:10 am

Elminster wrote:
Wed Jun 27, 2018 11:00 am
I should think reverse engineer pegasus would be fairly easy (well maybe not for me)
I emulate the Pegasus in MAME, it's a fairly standard 1770 implementation at &FCC4-C7, with the following control latch at &FCC0:
bit 0, 1: drive select
bit 2: side select
bit 3: density
bit 4: send DRQ to NMI signal (DRQ is ignored if this is not set)
bit 5: head load
- Nigel

BBC Model B: ATPL Sidewise, Acorn Speech, 2xWatford Floppy Drives, AMX Mouse, Viglen case, BeebZIF, etc.

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Re: Missing old/new Electron Expansions

Post by davidb » Wed Jun 27, 2018 11:41 am

A cartridge with an Espressif ESP32 to provide connectivity, and perhaps also to serve ROMs from its own RAM/ROM, would be interesting. However, it would need some level shifting because it looks like a 3.3V part.

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Re: Missing old/new Electron Expansions

Post by Elminster » Wed Jun 27, 2018 11:59 am

danielj wrote:
Wed Jun 27, 2018 11:07 am
Off you go then :D

(econet has been tried on the elk iirc, but it's horribly slow!)

Edit: sorry, that sounded a bit flippant! That wasn't really my intention...

It's quite a lot of work to do any of these things. Lots of people want lots of things. It'd be great if more people started trying to learn to do them and pile in to some of the open projects to enhance them. :) lots of support available. The more of us that learn the more things that get made!
I shall report you to the admins for your flippancy [-X

I would love to do them. Only trouble is my Acorn 8bit todo list is currently 80 items, and my SWTPC todo list is quite large, then there is my homebrew 6809 and 6502 projects. Plus my wife doenst believe in hobbies, so I was hoping to trick people into doing it.

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Re: Missing old/new Electron Expansions

Post by danielj » Wed Jun 27, 2018 12:05 pm

Likewise - but I've got an Apple project at the top of my list once this modem malarky's done. I have to not get distracted by the shineythings!

d.

Edit:
I should also say, Phill's reversed the peg, and done a layout in eagle IIRC?
Last edited by danielj on Wed Jun 27, 2018 12:10 pm, edited 1 time in total.

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Elminster
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Re: Missing old/new Electron Expansions

Post by Elminster » Wed Jun 27, 2018 12:10 pm

danielj wrote:
Wed Jun 27, 2018 12:05 pm
Likewise - but I've got an Apple project at the top of my list once this modem malarky's done. I have to not get distracted by the shineythings!

d.
Apple smapple.

I have done well this week and ticked half dozen things off my todo list (and only added one so far).

Just thought of an extra thing to add to Electron. A Plus1+1. I.e. a box with a through port between electron and Plus1 that let you add a couple of extra cartridges.

Edit: Something along the lines of the slogger plus 2.
Last edited by Elminster on Thu Jul 05, 2018 3:07 pm, edited 1 time in total.

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Re: Missing old/new Electron Expansions

Post by RobC » Wed Jun 27, 2018 12:31 pm

Elminster wrote:
Wed Jun 27, 2018 11:00 am
- With Viewdata board etc .... no mode 7 on Electron (tried the ROM but dont like it) .. no remake of the slogger board
- With videonula demos ... Well just need to prod RobC somemore on that one I guess
On these, I think we need a coordinated approach to the development of a new Elk ULA. I know it has been discussed in the past but I don't know where it got to.

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Re: Missing old/new Electron Expansions

Post by danielj » Wed Jun 27, 2018 1:01 pm

I do confess to thinking that the elk really *is* its ULA - replace that and you've not really got an elk anymore?

Or is that just me?

d.
Last edited by danielj on Wed Jun 27, 2018 1:01 pm, edited 1 time in total.

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Re: Missing old/new Electron Expansions

Post by Elminster » Wed Jun 27, 2018 1:40 pm

danielj wrote:
Wed Jun 27, 2018 1:01 pm
I do confess to thinking that the elk really *is* its ULA - replace that and you've not really got an elk anymore?

Or is that just me?

d.
That old chestnut. If it is a different sort of ULA that adds mode 7 and videonula then yes, maybe, perhaps (I still want one :) ) ? You dont have to change of course, I generally keep a pure Electron/Master etc. i.e. my spare Electron has no MRB, spare Master has no VNula, spare +1 has no AP6 etc. I doubt Rob et al. are going to turn up to you house demanding to remove you ULA from you Electron .... or will they :evil:

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Re: Missing old/new Electron Expansions

Post by danielj » Wed Jun 27, 2018 5:05 pm

:D

Oh no, do what you like with your elk :D It just feels, to me (and this is me personally, I don't expect anyone else to feel the same and I'm not saying for one second there's a right or wrong here), roughly akin to pulling the motherboard out and swapping it for a raspberry pi!

8-[

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Elminster
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Re: Missing old/new Electron Expansions

Post by Elminster » Wed Jun 27, 2018 5:24 pm

That would be kind of pointless. Although people do do that. I know I picked up an Electron MB from someone who did that. I have a pi-top for that. Much more useful.

Edit: Besides BITD Electron had mode 7 expansion, so that is proper retro. Only VNula it didnt have, and you could use the same arguement that the Beeb therefore should have Vnula.

Edit2: although videonula is based on a product that was about of course
Last edited by Elminster on Wed Jun 27, 2018 5:42 pm, edited 2 times in total.

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Re: Missing old/new Electron Expansions

Post by MartinB » Wed Jun 27, 2018 5:35 pm

I’m completely with you Daniel and in fact, that’s exactly why I’m a bit picky with even plug-in expansions. Indeed, I’ve said this before but you’ll see that all the projects and gadgets I’ve developed over the years are things that could just as easily have been produced back in the day. Old school, sentimental and proud of it.... :D

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Re: Missing old/new Electron Expansions

Post by Elminster » Wed Jun 27, 2018 5:43 pm

But so is all the stuff I outlined above

Most are remakes except vnula and econet. But those products were about, just not on Electron.
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Re: Missing old/new Electron Expansions

Post by MartinB » Wed Jun 27, 2018 6:06 pm

No, I'm fine with most of your suggestions, I was only really commenting in the context of the replacement ULA. That'll start small and just as a drop-in replacement ULA with the same functionality to future-proof spares but then it'll grow and grow becoming a modern monster with an embedded 200GHz super-computer with a massive light-speed DSP and more graphics power than you can shake a stick at.... :lol: [-X =;

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Re: Missing old/new Electron Expansions

Post by danielj » Wed Jun 27, 2018 6:08 pm

At which point you may as well stick a raspberry pi in it running b-em :D

d.

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Re: Missing old/new Electron Expansions

Post by 1024MAK » Wed Jun 27, 2018 7:17 pm

This discussion reminds me of a very similar one from another forum about a Sinclair computer....
What is it that makes it an Electron/ ZX81 / ZX Spectrum....

Mark

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Re: Missing old/new Electron Expansions

Post by Elminster » Wed Jun 27, 2018 9:43 pm

I think it is a common issue with old stuff. Do you just look at it (museum), do you use it as is, do you try to make it more usable (I.e. change it becuase spares no longer available etc.). Case in point being American 1930's car based hotrods (I didnt think of that I nicked the quote from 8bitguy episode I was watching earlier).

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Re: Missing old/new Electron Expansions

Post by pau1ie » Wed Jun 27, 2018 10:03 pm

My take is that this is my hobby. So the test is, do I enjoy it? Nothing more or less. Others may disapprove of changes I make to my equipment, but if they think it is important to keep something as it was, then presumably they will do this with theirs so some will be preserved in that way.

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Re: Missing old/new Electron Expansions

Post by 1024MAK » Wed Jun 27, 2018 10:25 pm

My view splits into a number of thoughts.

If an original component or part is no longer available, then a suitable equivalent part or module is acceptable as a replacement, even if it uses modern technology.

If the new facility is an expansion or internal upgrade that would have been possible during the heyday of the computer, again, fine.

If the new facility is an expansion that does add modern functionality, but the main processing is still performed by the existing CPU, then again fine.

If the upgrade is an internal modification, where the limiting factor back in the heyday was cost, or limitations of the available chips, then, again, fine (main example here being memory chips).

However, I don't see the point of adding a powerful modern 32 bit / 64 bit CPU complete with modern memory, etc where it takes over most or all of the processing. It's just about acceptable for second processors on a BBC Micro or BBC Master, as the Tube was included as part of the machine, and Acorn produced powerful second processors.

In practice I find I end up with one (or more) unmodified machines and a machine that I tinker with, that gets most of the upgrades / expansions... (so for example, I have a ZX81 where I have not done anything to it, other than fit a new membrane, meanwhile others have a modern 32K byte SRAM chip, modern DC/DC converter in place of the 7805 and a extra transistor to speed up the Z80 wait cycle during screen display synchronisation).
Same story with my BBC B's. I have not yet internally modified or upgraded any Masters yet.
With my Elks, again, so far no internal modifications. Just lots of external expansions... (Dave H. :D gets part of the blame here :lol: ).

Mark

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Re: Missing old/new Electron Expansions

Post by BigEd » Thu Jun 28, 2018 6:25 am

The thing about questions like 'is this a valid thing to do with an old computer' is that it's all about each person's approach. There can't be a right answer. And to any given answer there's sure to be someone who sees it another way.

I'm sure there would be interest in a ULA replacement, and there would also be people completely uninterested in it. Same with a Pi-inside-a-case.

I would prefer to see projects which can say 'no originally working machines were harmed' or 'no unsalvageable machines were harmed' but it's enough (for me) to be able to say 'enough unmangled machines remain.'

At The National Museum of Computing they like to have at least one original-condition machine. If they have that in a safe place then they feel free to put duplicates on display, to lend them to interested parties, or to try to restore or refurbish them. The more there are, the more free they are. It's when there's only one remaining example that they need to be very careful indeed - it still seems worth trying to make it work, but they must not lose the history or the authenticity. In the case of Phoebe, where there are only three known examples, one is pristine and one is being worked on. In the case of HEC, which is unique, I think they will eventually make up some modern replacement for the original drum (which IIRC is missing) - the replacement doesn't need to be a drum, it just needs to act like one.

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Re: Missing old/new Electron Expansions

Post by daveejhitchins » Thu Jun 28, 2018 6:54 am

Re the Electron ULA replacement project - One of it's main project drivers is to SAVE dead Electrons - There's no other way, unless, by some miracle, an old/new source is found [-o<

Of course, if you're going to all the trouble to replace the ULA then why not add features? Yes, you get carried away and before too long you have a part that is not only wanted by users with dead Electrons but by users that want to expand their Electrons. And so it goes . . . There will always be users that don't want the expansions but have dead ULAs - that's OK just don't add the switching capabilities.

A lot of the expansions, mentioned in the posts above, are on my to-do list - I just don't get enough time! But then I do like to 'produce' the items as though they were being produced BITD - it's just me :D

Dave H :D
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For a price list, contact me at: Retro Hardware AT dave ej hitchins DOT plus DOT com

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Re: Missing old/new Electron Expansions

Post by Elminster » Thu Jun 28, 2018 8:33 am

daveejhitchins wrote:
Thu Jun 28, 2018 6:54 am
A lot of the expansions, mentioned in the posts above, are on my to-do list - I just don't get enough time! But then I do like to 'produce' the items as though they were being produced BITD - it's just me :D
I think lack of time is a given. You need an apprentice or 3. Perhaps set yourself up as a Charity. "The Electron Rescue Home'

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Re: Missing old/new Electron Expansions

Post by 1024MAK » Thu Jun 28, 2018 8:58 am

Search the forum for RSPCA... :lol:

Mark

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Re: Missing old/new Electron Expansions

Post by Andy1979 » Thu Jun 28, 2018 9:23 am

I’m a big fan of any mods that give an old machine access to modern storage formats (SD/USB) or data services.

Beyond that, I think provided the machine can still run original software natively, then anything is fair game. There were lots of unofficial upgrades available back in the day and the remaining community of users are continuing that work - not dissimilar to the various ‘accelerator’ cards that are/were available for Amigas. If it means that someone can continue to use a favourite computer for more tasks, then why not? Most of these upgrades are reversible.

I don’t even mind the Raspberry Pi mods where the original motherboard is way beyond repair.

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Re: Missing old/new Electron Expansions

Post by dixiestoat » Thu Jun 28, 2018 1:47 pm

It still makes me smile whenever I plug a USB stick into my Datacentre Master... :lol:
If in doubt, CTRL-BREAK thou should clout..

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Re: Missing old/new Electron Expansions

Post by myelin » Fri Jun 29, 2018 9:34 pm

Elminster wrote:
Wed Jun 27, 2018 11:00 am
A couple of things got me thinking on various threads about what is not about for the Electron, a dredge of previous threads really.

- With Daniel's freewifi for the serial port ... nowhere to plug it in on Electron ... and no serial port remakes
- With Beebmasters Eco hubs .... dont think there was ever a produiction econet expansion, just prototypes or homebrews.
- With Gotek or disk .... no remake of the pegasus (although still old new stock floating about)
- With Viewdata board etc .... no mode 7 on Electron (tried the ROM but dont like it) .. no remake of the slogger board
- With videonula demos ... Well just need to prod RobC somemore on that one I guess
[...]
Would be good after 30 years if the Electron could do everything the beeb could do (and more)
Nice summary! Some of these would be a lot more work than others, and some of these would be a lot more useful IMHO.

I have a bunch of Econet-related stuff on the go, but no attempts to get it to work on the Electron. If a ROM image for an Elk Econet interface shows up anywhere, it would make this a lot easier. This would probably take up a whole cartridge by itself -- it would include the ROM, and could either reproduce the Econet module onboard, or have a socket for it. I've heard that existing Econet adapters are slow/unreliable on the Electron, but if they worked at 1MHz on the Atom, it must be possible to run them on the Elk :) I really like the idea of reviving Econet, especially if it turns out to be possible to bit-bash it on microcontrollers with a relatively simple interface circuit (no LM319 and sea of resistors for collision detection).

Adding a serial port or a disk interface would probably boil down to reproducing a cartridge from BITD that provided this.

MODE 7 and VideoNuLA support would be tricky, because all that happens inside the ULA (or not, in the case of MODE 7), and cartridges don't get A15 and A14, so they can't tell when the CPU is writing to the screen memory (unless you moved the screen memory onto the cartridge itself). They could go in an expansion or a ULA replacement.

I still have "make the ultimate Plus 1 replacement" on my to-do list, but actually deciding what the Electron *should* have, as opposed to just trying to turn it into a BBC Micro -- given that BBC Micros are fairly easily acquired these days -- is a hard job!
SW/EE from New Zealand, now in Mountain View, CA, making BBC/Electron hardware projects for fun.
Most interesting: Arcflash, FX2+PiTubeDirect Tube/Cartridge adapter, USB cart interface.

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Re: Missing old/new Electron Expansions

Post by Elminster » Sat Jun 30, 2018 12:03 am

myelin wrote:
Fri Jun 29, 2018 9:34 pm

I still have "make the ultimate Plus 1 replacement" on my to-do list, but actually deciding what the Electron *should* have, as opposed to just trying to turn it into a BBC Micro -- given that BBC Micros are fairly easily acquired these days -- is a hard job!
Fighting talk. I think you would have to just run with the spec you what, otherwise you would never start if design by committee, I bet ask 20 people you get 24 answers.

I think I (can’t resist), would just do a super plus+1 but just integrate AP5/6 and +3/Pegasus. Then you could squash up everything onto a few chips I.i a 256k ROM (for system software, AP6, DFS ( or ADFS), Basic, MOS), 256k eeprom and a 256k SRAM, and then the final 4 banks would be on the carts the same as now.

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Re: Missing old/new Electron Expansions

Post by rmbrowngr » Sat Jun 30, 2018 7:58 am

For me ULA replacement has to first priority as most hardware expansions are available even if not integrated into a single unit. I certainly would like to have the options to run my Elk without time penalties on memory access, have access to Mode 7 and maybe extended memory map for programs.

Secondly, or nice to have, a plus 1+, integrating many hardware expansions.
Richard B
Acorn Electrons issue 4 and issue 6 with Master RAM Board, Acorn Plus 1, AP6, AP5, Pegasus 400, BeebSCSI, Gotek, Raspberry Pi 2nd Processor, GoSDC MBE with Elk2GoSDC and Cart2GoSDC.
BBC B+ 64K (128K upgraded) with Duel OS

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Re: Missing old/new Electron Expansions

Post by hoglet » Sat Jun 30, 2018 9:47 am

rmbrowngr wrote:
Sat Jun 30, 2018 7:58 am
For me ULA replacement has to first priority as most hardware expansions are available even if not integrated into a single unit. I certainly would like to have the options to run my Elk without time penalties on memory access, have access to Mode 7 and maybe extended memory map for programs.
An Electron ULA replacement is certainly technically possible, but I think the cost would work out at ~£50-£60 which make it unattractive, given working Electrons can be had for about half this. So it's been stalled for over a year now.

(I've also been somewhat discouraged by the slew of rather negative comments recently)

The current status is a prototype exists which includes a Jafa compatible Mode 7 implementation, plus various turbo modes.
IMG_0694.JPG
viewtopic.php?p=150412#p150412

Dave

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