New Batch ROM / RAM Expansion Board for BBC B

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Joined: Mon Oct 18, 2004 4:35 pm
Location: Scotland

New Batch ROM / RAM Expansion Board for BBC B

Post by KenLowe » Sun Jul 07, 2019 3:41 pm


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 / 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.

Some photos attached for you to view:
IntegraB - Manual Front page.png

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Posts: 600
Joined: Mon Oct 18, 2004 4:35 pm
Location: Scotland

Re: New Batch ROM / RAM Expansion Board for BBC B

Post by KenLowe » Wed Jul 10, 2019 9:35 pm

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...
Integra-B User Guide - Rev 2.pdf
(978.71 KiB) Downloaded 10 times
Last edited by KenLowe on Wed Jul 10, 2019 9:43 pm, edited 1 time in total.

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