Prophet 2The Prophet 2 had an 32 K dynamic RAM card fiited on the PL6/7 bus and the Calc rom on the main board..
![](proph5th.jpg) dynamic RAM card |
![](proph6th.jpg) dynamic RAM |
![](proph7th.jpg) board + Calc ROM |
![](proph8th.png) Calc (IC20) PCB | Prophet 3
There's another
Prophet variant, the Prophet-3 which has a built in disk interface, a Polebrook Computer Services floppy disc controller card using an Intel 8271 controller chip, power supply and diskdrive in a 'plinth' type contraption. The Acorn dynamic 32K ram card and the FDC were both connected to the pl6/7 bus
Prophet 3
![](proph9th.jpg) on top bay + drive |
![](proph10th.jpg) Disk controller card |
![](proph11th.jpg) board + DOS ROM |
![](proph12th.jpg) FDC card, RAM card
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At last the Prophet 3 had a DOS. The tedious cassette filing system on 300 Baud was replaced with a floppy drive. Also the cabinet was adjusted to a new smaller form. Thanks to acorn.chriswhy.co.uk
Hobbit
The Hobbit Atom mentioned below has some interesting extensions on board. A graphic SRAM modification a 16 K SRAM card and a switching card model 1. The program memory is still present. The 16K SRAM is obviously used as an memory extension card. Both cards are connected to the PL6/7 bus.
![Atom type Hobbit](HobbitAtomk.jpg) Atom Hobbit
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Recently I found an Atom Hobbit computer. Early in the seventies a Dutch magazine "The Hobbit" launched a home brew computer called the Hobbit. See the item Atom kit in the main menu.
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![](Schak+SRAMk.jpg) Interior Hobbit Atom |
![](VideoSRAMk.jpg) SRAM video modification |
![](Schakk.jpg) Switch card on PL6/7 |
![](SRAMk.jpg) SRAM card on PL6/7 |
Expanded Atom cabinet
Another complete different Atom setup, is shown below. To make room for the extensions the original Atom cabinet was provided with a plastic frame glued on the bottom side from the original cabinet.
![zijkant](Dsc00017th.jpg) profile |
![achterkant](Dsc00019th.jpg) backside |
![Keyboard](Dsc00020th.jpg) Keyboard + display |
![](Dsc00021th.jpg) inside view |
On the main board are on the extension bus PL6/7 the switching card and below from that the 16K memory extension card situated. On the right side is the C-MOS video card replacing the original 2114 IC's.
![binnenkant](Dsc00022th.jpg) inside view profile |
![open zijkant](Dsc00023th.jpg) top view |
![schakelkaart](Dsc00024th.jpg) switching card |
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