Welcome to the RomCombiner BBC BASIC utility

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Introduction and History

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RomCombiner allows individual Z88 Applications to be combined into one external device. It cannot be used to add applications to the internal Flash chip in slot 0.

Historically, combinations had been made by Wordmongers, Ranger Computers and Steve Marsh for the Z88 User Group using the larger 128K or 256K EPROM cards. These were hard crafted and beyond the skills of the Z88 user. Gary Lancaster wrote the first version that allowed users to read Applications or combinations from ROM devices, Combine them, check that the target EPROM has been erased properly and then finally blow the combined result into it.

When the flash card and OZ 4.2 were produced, RomCombiner was modified so that applications could be added on these devices as well.

The Download consists of a zipped file which consists of the following files.

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Three files are used. RomCombiner.bas, romcombiner.bin and RomUtil.bas. These need to be either copied to the emulator, or transferred to the Z88.

Prerequisites, Planning and Using

As you are reading this on the internet, you already have one item, a computer that you can download the applications from. To demonstrate how to use this program, OZvm the Z88 emulator is being used so that screen shots may be used. Using the emulator has other advantages, these are:-

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Finally you need a link from your computer and the Z88, like Eazylink Eazylink2 and a cable, so that your compilation can be used on a real Z88.

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This description is assuming that a Flash card is used for the compilation. Unless you just want to add an additional application, making a compilation We start with adding some applications and then plan a larger compilation which needs a number of points to be considered. This requires planning and then execution. We will be using the Pareto principal (80% planning, 20% doing), so don't expect to be even looking at RomCombiner just yet.

Flash and EPROM cards may be used for Applications and/or the File Area. The main difference between these cards is how they are erased. The EPROM card is put into an eraser, exposing the chip to UV light. This erases everything on that card. The Flash card is erased within the Z88 itself and has the added bonus that it can be erased in 64K chunks. This means that the file area can be erased, whilst retaining the application area. If using a Flash card, to avoid wasted space, ensure the - Application area is in 64K chucks

Each application is allocated a letter called a Key and a name which can be changed i.e. [] Image AddedP for PipeDream. The second time and third time the key letter is used, a Z or ZZ is prefixed before that letter. If that letter is used again, it will be no longer available and will not be shown - i.e. ZP and ZZP. - A Key letter may only be used 3 times

It may be desirable to group applications into functions like, Word Processor, Communications, Files, Test, System Programs Database Utilities by - Changing the order. 

Example: Adding Applications to OZ

Making a list of Applications

The first step is to make a list of the applications required.

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• read from an existing ROM - using RomCombiner
• downloaded from the internet - which is what follows:-

Download OZ 4.7

The main page for all the OZ variants are here. Download OZ 4.7 zip file and unzip it. The files that are used are:

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These need to be either copied to the emulator, or transferred to the Z88.

Romcombiner uses these 16K blocks which are numbered 32, 47, 50 - 63.

How the 16K blocks are organised

These 16K files store the applications and data in the file area. The highest number, 63 is where all applications start. The OZ compilation of applications in this case is the 50 - 63 range. As the Flash cards can only be erased in blocks of 64K, the file area can only be within these 64K to prevent Applications from being erased when the file area is formatted.

That has happened here. Block 47 is the file header and 32 contains files that are in the file area. This means that blocks 48-49 are unused and may be used for additional applications without impacting the existing file area. This example demonstrates how two 16K applications may be added. If another application is added which uses block 47, the file header would be moved to block 43. This will reduce the file area by 64K but will give that 64K to the application area.

Using a Spreadsheet for larger compilations

Planning the compilation i.e. with PipeDream will allow

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The first items on the list are the existing Z88 applications. They have Application names and Key letters which need to be taken into consideration. An additional line is added at the top []top Image AddedI Index which although is not displayed on the Z88, the Key letter is used. The first column is a 'master order' column. You will see that we will need this to return our list back to where we started after the different checks we will be doing.

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