how to make a cdtv's cdrom switcher?

[jolly11]

hi,
I'd like to make a cdrom switcher for my cdtv, instead of remove the jumper continuosly. The reason is cause I want all the memory (1mb) available in order to play with amiga 500's games.
Any idea/suggestions? My idea is to make a power supply switcher for the cdrom, not powering it maybe frees some memory

[davideo]

Originally Posted by jolly11

hi,
I'd like to make a cdrom switcher for my cdtv, instead of remove the jumper continuosly. The reason is cause I want all the memory (1mb) available in order to play with amiga 500's games.
Any idea/suggestions? My idea is to make a power supply switcher for the cdrom, not powering it maybe frees some memory

@jolly11

I've got the details of this at home. I'll sort them out later and post them up on here if nobody else beats me to it.

Basically you just need a small switch and couple of other little bits. Remove the CD jumper and put the switch in its place. Flick the switch one way and your CD drive works the other way and it doesn't. Easy peasy.

I had one fitted on my CDTV and it worked a treat

Dave G

[davideo]

@jolly11

Here's the instructions for your CDTV drive disable/enable

How to disable the CDTV functions. 
To do this, open the CDTV up, and remove the jumper on JP15,
which is near the front centre of the CDTV.
Removing this jumper disables the CDTV functions,
placing it on the left two or right two pins (it doesn't matter which)
will enable the CDTV functions. 
You could put a SPST switch across the left two or right two pins
and this would allow you to disable and enable your CD-ROM.
To enable the CD-ROM drive flip the switch to on and
to disable the CD-ROM flick the switch to off.

Of course, enabling or disabling the CDTV function
should be done with the CDTV power off.

Have fun

Dave G

[alexh]

While this is a more expensive solution; the creator of the IDE68k expansion is planning a version with RAM. This is almost the perfect expansion for CDTV. 8MB RAM + IDE interface.

http://www.students.tut.fi/~leinone3/ide/ide68k.html

[Toni Wilen]

Originally Posted by alexh

While this is a more expensive solution; the creator of the IDE68k expansion is planning a version with RAM. This is almost the perfect expansion for CDTV. 8MB RAM + IDE interface.

http://www.students.tut.fi/~leinone3/ide/ide68k.html

This does not really fix the problem (makes it worse actually) which is A500 game compatibility

[alexh]

I understand what you are saying. If playing from floppy disk is the goal then it is not the solution.

However with Fast RAM in a CDTV you can run WHDload from CD (or IDE). No more messing around with floppy disks.

[Shadowfire]

In a CDTV... for best A500 compatibility experience:

1. Disable CDTV ROMS, via the already-mentioned jumper.
2. Use a mouse/keyboard/joystick, via an adapter.
3. Add an external floppy drive, which the system will recognise as DF0:

The above scenario is pretty good as far as compatibility; however it does have some deficiencies:
The 1MB of memory is all chip memory, and all at $000000-$0FFFFF, Old games which expect slow-fast @ $C00000 will break. Games expecting only 512K can be made to run with degrader or a similar utility.
The Kickstart version is 1.3; there are still a few old games that demand 1.2 to run.

WHDLoad is *not* going to happen on a CDTV without expanded memory. And there are a small number of installs that demand a 68020 to run (even if the original worked on a 68000).

[jolly11]

thanks to everyone!

@davideo: thank you very much..do you also have a picture?