What is the System ROM?
The system ROM is fitted in the top socket of the row of sockets going up the right hand side of the main board (the sockets that you fit your own EEPROMS etc into). It holds the Machine Operating System, BASIC, View, Viewsheet, EDIT, ADFS, DFS and Terminal.
Before Anything Else.
Firstly, ensure that your system ROM is not soldered to the main board, apparently some are. If the system ROM is soldered into the mother board you may not want to upgrade due to the fact you may have to problems de-soldering the old ROM and fitting a socket for the upgrade.
What Does The Upgrade Consist of?
The upgrade consists of a new system ROM and small manual. The manual contains full fitting instructions and information about the changes made.
How do I upgrade the System ROM?
Pull the original system ROM out and store it away. Push the new system ROM in. That is all there is to it!
What Changes Have Been Made To The System ROM?
Changes to the Machine Operating System (MOS)
Support for characters with the top bit set.
*BUILD and *APPEND accept characters with the top bit set.
*SHOW shows all the function key definitions 0 to &F.
You can generate a nul character with CTRL+0.
*UNPLUG unplugs all identical copies of a ROM.
*REMOVE will not work with *REMOVE file1 file2. Handy if you have done as I have and typed *REM. file1 file2 instead of *REN. file1 file2. Try it on a file that doesn't matter!
A new relocator which relocates BASIC and EDIT automatically when being used in a co-processor. No more HIBASIC. More memory free.
Changes to Terminal.
Changes to View.
*CONFIGURE SETUP [F],[J],[I] so View comes on in the configuration you want. Epson printer Driver included in the ROM
Changes to ADFS.
Improvement in speed when accessing floppy discs.
*COMPACT no longer needs arguments
*COPY, *BACKUP, and *COMPACT may use all of shadow screen memory.
Changes to Edit.
The *EDIT command is not checked so rigidly.
Automatically re-locates on a second processor.
Handles characters with the top bit set.
Handles both carriage returns and linefeeds, can toggle between the two.
You cannot load a new file without confirmation.
Status line shows the TAB state.
Extended set of responses to the clear text command.
Inserting a file no longer changes the current filename.
New mode command uses GET instead of INPUT.
As is command added to printout.
Changes to DFS.
You can save files longer than 64K
All 4 step rates now used.
OSGBPB works more quickly.
CLOSE#0 bug removed.
Changes to BASIC.
Automatic re-location on the second processor.
Various trigonometric and logarithmic functions speeded up.