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Just got a BBC Micro Model B, and I have questions!


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So like the title says, BBC Micro, Issue 4, Model B.  

 

At the moment, I'm still in the process of fixing the power supply, as the seller was kind enough to inform me that it failed a smoke test before he sold it.  As such, I've replaced the two RIFA caps, and removed the third electrolytic recommended.  However, two of the 250v 100uf capacitors were bulging on top, and discovered some slight leakage after I removed them.  I have some 450v replacements that might/should work.  I'm in the States, so I've been considering converting it to 115v, but I have a 250v step-up converter, so it's not a priority.  

 

Overall, the computer is in pretty fair shape.  It was missing all its case screws but I found some suitable replacements.   However, the vinyl on top is cracking and chipped along the right side of the keyboard and the user-ROM slot has been punched out.  Question one: Is there anyone who makes a suitable replacement?  I could fashion one, but I'd lose the labeling for the lights.

 

Inside it has a Sidewise board (not entirely sure what's on it) which is attached to two switches on the back.  Which leads to my second question:  Would the Sidewise interfere with the User-ROM?  I was considering adding a ZIF Socket (to plug the hole if nothing else), but I wanted to know how functional that would be?  I've also seen an edge connector?  Seriously, what would that be for?  

 

Additionally, there's a spot below the keyboard that I've seen some people (pictures and YouTube videos) where people added dip switches but they never explained why?

 

Also, there's what I'm guessing is a double-density(or 2-sided) floppy board installed.  But I know how proprietary the drives are?  If I could get the right connector, could I adapt a standard PC drive?  I also have a drive for a TRS-80 and Apple II, though I doubt that the latter would work.  At some point I was going to get an SD solution, but floppies can be fun too.

 

My next question regards ECONET.  At the moment, my computer doesn't have it installed, but I was thinking of adding it.  But what are the advantages and limitations?  Can I use it to network to other 8-bit micros?  Or am I limited to other BBC's?  Can I use it to connect to outside servers?  I understand these things can still connect to the BBC News feeds, but I'm not sure what I would need to do it?  

 

Lastly, is there anything else I should be looking into?  Games?  Accessories?  Upgrades?  Other add-ons that might be fun to play with?  Any advice would be appreciated!

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Update:  IT WORKS!!!  

 

I had to reset that Sidewise board more times than I could count.  But eventually, I got it in.  All keys have been tested good.  Also, I've left the PSU at 250v for the time being, as I like keeping my machines as original as possible.  

 

On boot it displays:

 

32K 

OPUS DDOS 3.45

BASIC

>_

 

BASIC programs work as expected (when compared to my Electron, but a little faster).  Not sure what Opus DDOS is, but I have it.  As for the two switches on the back...  No clue.  Switching them up or down has no impact on boot behavior.  Still looking into the other ROMS.  Will post a picture of the board soon, but for now I'm going to play in BASIC!

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Usually, standard Shugart type floppy drives should work. I think with the correct jumper setting even a PC drive should work so nothing particularly proprietary there.

 

I don't know about switches or the expansion, but on my unit I installed 32K sideways RAM many years ago into one of the ROM sockets and cutting a couple of wires on the motherboard. Perhaps your expansion already adds that RAM memory, otherwise it is worth looking into as it allows various floppy systems like DFS, ADFS etc to load into high memory, leaving the standard 32K for programs. I found that my Beeb became much more useful with that. I'm having some kind of IDE interface that plugs into the 1 MHz bus, running XADFS. It was soon discontinued in favor of better products, but it works for me. I also have a 40/80 track floppy drive (and an Acorn Electron, but that is beside the point).

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On 4/1/2023 at 10:55 AM, carlsson said:

Usually, standard Shugart type floppy drives should work. I think with the correct jumper setting even a PC drive should work so nothing particularly proprietary there.

Thanks for this!  I have an external PC 360K drive that might work.  But I'll probably need to make a new cable for it.

 

On 4/1/2023 at 10:55 AM, carlsson said:

I don't know about switches or the expansion, but on my unit I installed 32K sideways RAM many years ago into one of the ROM sockets and cutting a couple of wires on the motherboard. Perhaps your expansion already adds that RAM memory, otherwise it is worth looking into as it allows various floppy systems like DFS, ADFS etc to load into high memory, leaving the standard 32K for programs. I found that my Beeb became much more useful with that. I'm having some kind of IDE interface that plugs into the 1 MHz bus, running XADFS. It was soon discontinued in favor of better products, but it works for me. I also have a 40/80 track floppy drive

I made a similar post on VCF, and it was suggested that they might be for enabling and wright protecting a RAM disk.  Basically, if they're right, I can load a ROM image into RAM.  There's a battery on the board (likely dead, but thankfully not leaking) that would preserve the image between power cycling.

On 4/1/2023 at 10:55 AM, carlsson said:

(and an Acorn Electron, but that is beside the point).

ME TOO!!!!

 

Below are some pictures.  If anyone could tell me what the rooms are it would be appreciated.

900666613_Screenshot2023-04-02at7_22_45PM.thumb.png.18756c2d319a210edf37a1def8ba622d.png802679305_Screenshot2023-04-02at7_22_26PM.thumb.png.dffbd73dc2522ad54e9bbff90b1b0372.png254786386_Screenshot2023-04-02at7_22_17PM.thumb.png.14608b0e9a0bf1fa215266e51e134b0f.png1106845970_Screenshot2023-04-02at7_22_04PM.thumb.png.6d0c19935d8b03b335b7e0e7f7182826.pngimage.thumb.png.514c7d4fc55b1616445bb9c600357d2b.png

748889775_Screenshot2023-04-02at7_21_44PM.thumb.png.aea38404e73d1059fcabf1cb22b42d7c.png1366879789_Screenshot2023-04-02at1_42_39PM.thumb.png.0aa9caba5bdaf0e824551a51fe8f9e98.png

 

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