New Batch ROM / RAM Expansion Board for BBC B

[KenLowe]

Hi,

I've had a few requests from various sources for a second batch of IntegraB boards, so I ordered up another small quantity of PCBs and built these up over the last few weeks. The routing errors that were in my first batch have been fixed on these boards. I'm primarily selling these new boards via eBay, but if anyone on here is interested, I will be able to sell at a discount (£72.50 inc. UK delivery instead of £82.50). As a reminder, the board consists of the following:

• 8 x Expansion sockets for 8k / 16k ROMs. 4 of these sockets can be used for 32k ROMs / write protectable battery backed RAM / EEPROM / Flash / FRAM (banks 8 thru 15)
• 4 x 16k write protectable battery backed RAM banks (banks 4 thru 7)
• 20k Shadow RAM
• 12k Private RAM
• Y2K compliant RTC
• IBOS (IntegraB OS) / Basic in a combined 32k EPROM. This uses one of the 32k ROM sockets on the IntegraB board

Installation is fairly straight forward. No soldering required. The 6502 processor needs to be removed from the BBC motherboard, and inserted into a socket on the IntegraB board. The board then plugs into the 6502 socket on the BBC. There are also 3 wires than need to jumper from the IntergaB board onto existing jumper pins on the BBC motherboard, which allows access to the 4 ROM sockets on the main BBC motherboard (banks 0 thru 3). Additionally there are 2 power wires than need to be re-routed from the BBC to the IntegraB, and 2 wires from the IntegraB back to the BBC motherboard.

The board has been tested and will happily co-exist with DFS*1 / Floppy drive / Gotek, Econet, VideoNula, Datacentre, 2nd Processor / Pi Copro, GoSDC / GoMMC, MMFS, BeebSCSI / Winchester HDD, speech synthesiser, various PALPROM solutions (like SpellMaster 128).

Note, however, that the IntegraB will not work with BBCs that have had wiring modifications to accept 32K ROMS / RAM / EEPROM in the 4 ROM sockets. This is because the IntegraB uses some of the same ROM slots that have been assigned to the modified sockets on the mainboard. I recommend that you reverse any wiring mods to the 4 ROM sockets before installing the IntgeraB.

As mentioned previously, price for this batch will be £67.50 + £5 UK postage, and I will be looking for payment via Paypal gift. I may be able to do international delivery, but please contact me for international postage costs.

For this price, you will get the following:

• IntegraB board as described above
• 32k PROM pre-programmed with IBOS and Basic. This will be pre-installed in IntegraB ROM socket 15 (ROM banks 14 & 15)
  User Guide
• 2 x Self adhesive support strips
• 40 pin socket extension
• 2 wire power lead to connect between the IntegraB board and the main BBC motherboard
• 3 wire signal lead to connect between the IntegraB board and the main BBC motherboard

In addition, I also have a small quantity of 32k EEPROM and RAM modules that I can supply with the board. Each additional module will cost £2.50.

If interested, please note interest below, and we can take it to PM for payment and delivery details.

*1 Please note that if you have a 1770 expansion board with ICs fitted on the underside of the board, it is possible this board has been fitted with an extension socket to lift it above the speech chip IC93, and it may be necessary for me to install the IntegraB power socket in a slightly different location to remove a clash between the IntegraB board and the elevated 1770 board. The latest 1770 boards sold by retroclinic and ctorwy31 have the ICs mounted on the topside of the board, and will not cause a clash. If you have any doubt, please contact me so I can advise you.

Some photos attached for you to view:

[KenLowe]

Sorry for the bump. I tried to edit my earlier post to add an updated User Guide, but I think there must be a limit to the number of attachments I can add to an individual post. Updated User Guide attached here...

[KenLowe]

That's a small batch completely built up and ready to ship. The most time consuming bit is getting all the 'extras' sorted! The observant amongst you might have spotted that some of the packages are missing the 40 pin extender. I'm just waiting for a new batch to arrive. Hopefully they'll be here early next week.

After this batch is sold, I've got another batch that has been built, but still needs to be packaged up with the extras. Those will also be put up for sale, but once they're gone, that'll probably be me done with them. Mission accomplished from my point of view. I now have a couple of spares in the event that my original fails! Next project is probably an easier one. I want to build a number of SCSI host adaptors to use with a batch of Fujitsu 256 byte sector compliant SCSI drives that I have lying around.

Integra-B boards ready to ship

[tucker]

Hi

I’m a bit late to the thread and just restored an old beeb I used back in the 80s then recently had donated from a friends attic find. It will go nicely with my maxed out master!

Now in process of accessorising. Wondering if there is any possibility of getting one of these? Long shot I know but no harm asking .... hoping ...

[KenLowe]

Hi tucker,

I've still got a few left. If you're still interested, lets take it to PM, where we can sort out payment and delivery details.

Also, just double checking that it's a BBC B that you're wanting to install this into and not a Master?

[simply_graham]

Hi Ken

I'd like a board please, if you just have the PCB, and kit of parts happy to put together myself, as I'd use all Turned Pin sockets throughout (
Also save's you some soldering ..
I did try to PM you, but not sure I'm allowed, only Just joined the board, having purchased a working Beeb on fleabay .. Oh and its not arrived yet so may need to converse with you in regard placement of power connectors if board already built.
BR
Graham

[1024MAK]

Hi Graham

Welcome to StarDot

You may wish to say hello in the introduce yourself section.

Private messages (PMs) are disabled for new members at first. However you can ask for PMs to be enabled by using the Contact us link (envelope icon) at the bottom of every page. This sends a message to the admin’s who will consider your request.

Mark

[KenLowe]

Hi Ken

I'd like a board please, if you just have the PCB, and kit of parts happy to put together myself, as I'd use all Turned Pin sockets throughout (
Also save's you some soldering ..
I did try to PM you, but not sure I'm allowed, only Just joined the board, having purchased a working Beeb on fleabay .. Oh and its not arrived yet so may need to converse with you in regard placement of power connectors if board already built.
BR
Graham

Hi Graham

Welcome to Stardot, and congrats on the new beeb!

Unfortunately, I don't have any bare PCBs left. All I've got left now are pre-built boards. I'll drop you a PM shortly (you should still be able to receive PMs) with alternative contact details.

As an aside, when I built the first couple of boards, I also used turned pin sockets throughout. However, I noticed that some of the narrow 20 pin sockets didn't make a particularly good contact with the chips causing all sorts of problems when it came to testing. I'm not sure if I just had a bad batch of turned pin sockets, or if the legs of the ICs were a bit out of tolerance, or if it was a combination of both, but it certainly caused me a number of issues. I therefore decided to solder all dedicated ICs direct onto the board, which resolved all those issues. Please note that there are no such issues with the ROM or processor sockets which are still on the board.

[M Sadler]

Hi Ken
Interested in purchasing on of your IntegraB ram/rom expansion boards. Please send me PM.
Regards Michael

[KenLowe]

Hi Michael.

Thank you for your noted interest in one of my boards.

Unfortunately, I'm currently on holiday, so I wont be able to send you one immediately, but I'll drop you a PM on Monday when I'm back in the UK and we can take it from there.

Thanks
Ken.

[KenLowe]

That's me back in the UK now. I've dropped you a PM, so please review and get back to me when you get a chance.

Thanks
Ken.