SuperBoard II ROM/RAM Upgrade

[Frank]

After 30 years i pulled out the 600 board and it works.
Only just 8KB RAM is not enough for loading OS-65D.
To free some sockets for RAM i combine the four Basic-ROMs to one 27C64-150.
Three free sockets are now available.
In one i took a 62256-80 RAM and bend the not fitting pins up.
Only a 74LS32 is needed to combine /Phi2 and A15. That is for /CS.

If there is an interest, i can documented more of the things to do.
There are no cuts neccessary for this conversion.

Greetings from germany,
Frank

[dave]

Hi Frank,

Yes, it would be great for you to document your mods here.

Best regards,

Dave

[Steve Gray]

Nice work!

Yes, it would be nice to document your modifications.

Do you have a floppy drive on your system? What monitor rom are you using?

Steve

[Frank]

Hi Steve,
i will document it in the next week.
Yes, i have connected a floppy drive.
in 1982-1985 the "Elektor" Magazin published a OSI-compatible floppyinterface.
http://retro.hansotten.nl/uploads/eljun ... nior82.pdf
With an adaptercable you can connect it as it is to the expansionconnector of the 600-board (i do it w/o the 8t28 driver, only bridged).
You can use standard flopydrives with this floppyinterface, because the dataseparator is onboard.
My Monitor-Rom is a special version from a berlin specialist, who add some features. i missed my original 600 monitor-ROM.

With this configuration i was able to copy all my OSI-Disks (I found only 6 working copys out of this time).
All disks are now copied to a new blank disk without any errors (After so many years ).

Best regards
Frank

[Steve Gray]

Some nice info in that PDF! I wish I could read german

It would be nice to see some pics of your system. Would it be possible to dump your monitor rom for all to try? I can host it on my own C4P web page if you don't have a spot for it.

Yes, I'd like to back up my disks. Last time I tried most of mine were working, but that was a few years ago.

Steve

[Frank]

Hi Steve,
it is written in dutch.
Dutch is partial similar to german, but in many cases strong to read for me.
The link below is written in english and descibes the VDU-card for the system with patches for OSI-DOS.
http://retro.hansotten.nl/uploads/eljun ... ducard.pdf
Yes, i readout the special monitor ROM.

Frank

[Frank]

I make a schematic for the RAM upgrade.
Also there is a combined BASIC-ROM file that fits in the 27C64.
If there are any questions, ask me.

Frank

[dave]

Hi Frank,

Thank you for documenting that. I have added your mod to the tips/tricks section of the website, along with a transcript of this thread as a kind of read-me file. Does the consolidated BASIC image include the garbage collection fix? If not, I can provide a fixed ROM image.

Best regards,

Dave