With modern computers we are used to have storage built into the device, sometimes even cloud-based storage. But back in 1985 when the Amiga was born, storage was usually on Floppy disks.

This is part three of this project where we will look closer at the boot floppy and optimise that limited space while leaving room for saving settings, etc. 

This is a Work-in-Progress. please check the changelog for further details. Last edited: 17/9-2019 15:15

For this we are going to need the Productivity 2.1 Boot floppy disk and the set of AmigaOS floppy disks that corresponds to this version; Extras 2.1, Fonts 2.1, and Locale 2.1. There is also an Install 2.1 but at the moment we are not likely to use it.

First off, let us take a look at the Workbench Boot floppy we prepared in the previous part:

(screenshot of WB window)

My version of the Productivity 2.1 (Workbench) Boot floppy has 162KB free space on it. Your Mileage may vary. We need to tailor this boot floppy to our needs.

Keymaps

First off, I am using a Danish keyboard, thus I would like to include this in the Keyboard drawer so that I can select it in Preferences. If you are using an American keyboard you can skip this following section and go down to the Preferences section

The keyboard definition files can be found in a drawer named Keymaps on the Extras 2.1 floppy in the Storage drawer. So lets insert and open up the Extras floppy, open the Storage drawer and then the Keymaps drawer

Move the Keymaps drawer window to the left and look for the the keymap(s) you need - in my case dk:

Then in the background open up (double-click) the Devs drawer of the Productivity 2.1 Boot floppy. In the new window open the Keymaps drawer

Then click and drag the keymap(s) that you need from the Keymaps window on the left (from the Extras 2.1 floppy) to the empty Keymaps window on the right (our Productivity 2.1 boot floppy):

If you look closely at the screenshot above the free space of out boot floppy has gone down to 159 KB - so this keymap took up about 3 KB of disk space.

If we wanted to, we could also change the language - the Locale - of our AmigaOS. This is done by moving the appropriate files form the Locale 2.1 floppy to our boot floppy. I am not doing this for two reasons: 1) I actually prefer to have an English AmigaOS. 2) The locale catalog files that provide the alternative language(s) take up extra space - space that is at a premium in our setup. If you would like to change your Locale, please locate these files on your Locale 2.1 floppy

Preferences

Now we can select the Keymap we copied onto our boot floppy. Lets close all the windows except Extras and Productivity 2.1 Boot. If you look at the boot floppy there is a Prefs (preferences) icon. This is actually a Drawer where our presets are stored.

To save space on this floppy, all the programs that can modify our preferences has been moved to the Extras floppy. We only need these preferences programs when we want to change our preferences - the settings themselves are stored in the Presets drawer we saw earlier.

So lets open the Prefs drawer from the Extras 2.1 floppy:

Feel free to explore the different preferences programs. Most names are self-explanatory.

I am going to change preferences in two sections, Input and ScreenMode. 

If you are using an American keyboard this is already the default and you do not have to change it. I would like to use my Danish keyboard so I select Dansk and click Save, which then closes the Input Preferences programme.

Next I am going to change the ScreenMode. Double click ScreenMode:

My Amiga 500 has the PAL Old Chip Set (OCS) Denise chip that produces the video output. So I have access to two different Display Modes: PAL:640 x 256 and PAL: 640 x 512 Interlaced. NTSC versions of the Denise chip would have NTSC:640 x 200 and NTSC:640 x 400 Interlaced.

The difference between these two is that the number of vertical lines are doubled by switching quickly between 2 different images, one with all the odd lines and one with all the even lines. This often creates a flicker on most CRT (Cathod Ray Tube - old style TVs) screens which is displeasing to the eyes, especially as on a TV only 50 (PAL) or 60 (NTSC) frames are showed per second. With a quicker framerate this would be less noticable.

If your computer has the ECS (Super) Denise you would also have a 1280 x 256 and 1280 x 512 Interlaced (NTSC: 1280 x 200 and 1280 x 400 Interlaced) at a maximum of 4 colours

In addition, switching to Interlaced mode makes our Workbench screen 'squished' as icons and windows are not scaled - they are simply just displayed as is.

I would like to have access to more than the default 4 colours on the Workbench screen. This will allow us to have more room for making better looking icons later. We can change that by sliding the bar next to 'Colors' to the right or left. We have the choice of 2, 4 (default), 8 and 16. I will choose 8, but you are free to make your own choice:

 

This change is not strictly needed and will cost us some ChipRAM. If you would like to preserve ChipRAM you can opt to stay at 4 colours.

Again press Save. The screen will blank for a short moment as it changes the colour depth. When it comes back on, there is no visible change except that the available ChipRAM has lowered. This is because Workbench and its default icons is designed to work with 4 colours. If you click on the Palette icon you can now see the extra colours available. You can change each of the colours to your own liking thus creating your own environment. For now I will keep the default colours:

Tools

The last thing we are going to do in this part is to copy over MicroEmacs or MEmacs as it is called over to the boot floppy:

On the boot floppy create a drawer and call it Tools:

Open the drawer and then open the same drawer on the Extras 2.1 floppy:

Drag the MEmacs icon from the Extras 2.1 drawer to the empty Tools drawer on our boot floppy.:

Startup-sequence

Most computers have a start up sequence. In Amiga OS this is placed in S:Startup-sequence. We are going to edit this file to tweak it for our use.

Start by double-clicking the MEmacs icon. MEmacs is a fairly simple but powerful editor for its time and it is included in the Amiga OS. In the course of our later parts we might replace it, but it will do for now.

MEmacs is made to use keyboard shortcuts and if you are going to use it a lot, it would be well worth the time to learn these keyboard shortcuts. That is out of the scope of this part though. Thankfully MEmacs also has a Menu builtin.

Open the file S:Startup-sequence:

find the line that says:

AddBuffers >NIL: DF0: 15

It may say another number than 15. Change this number to 30. AddBuffers adds a disk buffer in memory so that frequently used blocks does not have to be read off the floppy every time they are accessed. The more buffers, the less re-reads are requied. However buffers uses memory that could be used better by the main system. This is always a trade off.

Further down the file there is a line that reads:

Echo "Amiga Release 2.1. Kickstart ......."

After that add the following lines:

Echo ""

Echo "Productivity 2.1"

Echo "https://www.kaddu.dk/janholbo/amiga/projects/35-productivity21"

Finally save the file and exit: 

That is all for part 3. When you are ready, move on to part 4 (to be continued)

 

This is part 3 of several (planned) parts. Here is an overview of the parts:

 

Changelog

 Version Date  
 0.1 2019-09-16 Initial edition

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