New Zealand Vintage Computer Forums

Hi all,

I was just casually reading about System 80 related things when I realised that my System 80 has an option rom installed in socket 4. Up until this point I assumed it was stock; but now I realise that one of the previous owners must have installed it. How might I go about determining what is on it? I could probably dump the contents using my MiniPro eprom programmer; although I can't easily read the chip type (it has an ugly deteriorated sticker on it). Can I somehow look at / determine the contents on the system 80 itself? I am hoping it might have some sort of DOS on it or something.

Second question is how easy is it to back up and create spare system roms (the 3 other ROM chips)? Can I dump them using the MiniPro eprom programmer and burn them to new chips? If so what eeprom/eprom chips should I buy? The part numbers on the original rom chips don't get too many results when I search for them in Google. The main reason I ask is that occasionally I have to reseat them to get the 80 to boot. This could indicate a socket or intermittent IC fault so I would like to have some spares on hand.

Thanks,
Matthew.

Hi Matthew,

The forth (often optional) ROM you mention is a standard 2716 EPROM. You should be able to read it with your EPROM reader. You can also view it from the System 80 itself with an assembler. The address is from 12288 to 13823.

If it is a blue label model or the mk II business model then the ROM will be factory fitted. They have utilities in them which can be activated by going to an address. Details of what those utilities are can be found in the users manuals here.
http://www.classic-computers.org.nz/sys ... tm#bundled

If it is a standard black label it could be a utility ROM like that mentioned here
http://www.classic-computers.org.nz/sys ... ilityEPROM

As to the second question, yes you can use 2732 EPROM chips to replace the standard Mask ROMS BUT they are not directly compatible. A little bit of rewiring is required under the socket. You can read them with an adaptor but I wouldn't bother as a binary dump of the ROMS are in the System 80 zip file here.
http://www.classic-computers.org.nz/sys ... lators.htm
although you would have to split the ROM file into it's 3 (or 4 parts). Or just contact me and I'll send you the three ROM binaries.

Thanks for that Terry, I thought the EPROMS were some sort of weird pinout.

I've taken some copies of the saved ROMS from your site just in case I need them someday. At this stage it looks like my intermittent fault is more a problem with the socket than the MASK ROM's (as I have found mask roms rarely fail).