ATPL SideWise - Sideways ROM for BBC Micro

 

"The ATPL SIDEWISE BOARD provides an expansion of the SIDEWAYS ROM facility of the BBC COMPUTER, increasing support from four devices up to the maximum of sixteen supported by the OS. Each device may be either 8K  or 16K bytes in standard configuration with some useful options selectable by links on the board. The socket for ROM number 15 has been split into two 8K sockets -15a and 15b- to allow use of 8K byte CMOS RAM chips and therefore provides support for up to 16K of SIDEWAYS RAM. The logic is arranged such that any write performed to the SIDEWAYS ROM area of the machine will access the RAM directly, irrespective of and without affecting the current ROM selected. The RAM may be read as a normal SIDEWAYS ROM by writing the appropriate number into the latch at HEX FE30, as performed by the OS.
The most obvious application of the RAM option is in the development of SIDEWAYS ROM software, as the interaction with the OS may be checked out in the true SIDEWAYS ROM environment. The RAM option will also allow you to download SIDEWAYS ROM software from cassette or disc and then to run as normal. By addition of a few components, the RAM may be backed up by a battery to allow for retention of data in the RAM even with the power to the computer removed. A WRITE PROTECT facility may be added to the board simply by fitting a switch, as may a RAM READ DISABLE facility - to get you out of trouble should your development software CRASH within the RAM and lock you out of the machine! It is also possible to fit an 8K ROM together with 8K RAM as device number 15, thereby allowing a ROM to have private access to its own 8K RAM workspace.

 

In standard form, SIDEWISE is supplied ready to PLUG-IN-AND-GO - no soldering being required. The board will accept 16K of RAM simply by inserting appropriate devices, but the battery backup circuit and RAM chips are available at extra cost as a kit from ATPL."

 

Item is tested and in good condition and in good working order.
Supplied with a copy of the manual with installation instructions.