Acorn BBC

I never owned a BBC back in the day but I used to work with them both repairing them, and using them.

Now I have had some time learning about the MOS and BASIC on this system I can liken the BBC to how some cars are built around the driver, the BBC is built around the programmer. I can now remember why I enjoyed programming so much when I started out! (Years of PC and Windows development has dampened the enjoyment that was there unfortunately).

As an aside, Mobile and HTML5 development has certainly improved on the enjoyment factor. :-)

Solid State Storage

Now I have a BBC finally in my collection the biggest initial issue is how do I get software onto it, and also save anything I might create on it. Of course I could get a disk drive for it but then I saw that you could use MMC flash memory cards on it.

I found this site which details a circuit to build your own MMC interface complete with a patched DFS ROM image and PC software to create and manipulate the disk images.

MMC Circuit board
I changed the IDC DIL Header to a male header connector as the DIL Header is not available at Maplin anymore, this also means that I have a user port cable which I can easily connect to another hardware device without unplugging from the BBC itself and also saving having to purchase additional ribbon cables.

Although the circuit is easy to assemble for anyone experienced in electronics, you also need access to an EPROM programmer.




User Port
01 – +5V
02 – CB1
03 – +5V
04 – CB2
05 – GND
06 – PB0
07 – GND
08 – PB1
09 – GND
10 – PB2
11 – GND
12 – PB3
13 – GND
14 – PB4
15 – GND
16 – PB5
17 – GND
18 – PB6
19 – GND
20 – PB7

At first the pinouts above may seem odd, until you consider the physical layout of the IDC cable (see image above), effectively the 5V and GND lines are along the top of the connector, and the data lines along the bottom, also there is the advantage that the data lines are separated on the cable between ground lines.


This entry was posted in Vintage and Retro Computing and tagged , , by Sean. Bookmark the permalink.

About Sean

A self motivated highly experienced software developer and IT professional. Extremely technical, thorough and with excellent problem solving skills. Able to develop on a wide variety of systems and integrate heterogeneous platforms together. A proven track record of project successes from conception through to delivery. In depth knowledge acquired through exposure to a wide variety of technologies.

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