While browsing the local flee market, I've brought home a random bag of old electronic parts, including EEPROMS. The original plan was to erase them and reuse them.
My curiosity got the better of me and I've dumped the content of the EEPROMS. They contained OS ROMs for Iskra Delta Partner computers.
Iskra Delta Partner
Iskra Delta Partner was a computer developed by Iskra Delta (Slovenia) in 1983. A family of desktop computers that were created to be small business and/or development systems. The Operating System was CP/M 3+ and it had built in monochromatic monitor, there were three versions of the computer:
WFG - graphical microcomputer PARTNER with winchester disk and one disk unit.
2FG - graphical microcomputer PARTNER with two disk units.
1FG- graphical microcomputer PARTNER with one disk unit.
If you're interested in details, you can find more information on this pages:
A documentary about Iskra Delta (the company), unfortunately in Slovene:
OS ROM
So what is an OS ROM? In a context of old computers it's basically the firmware (software) that allows the software layer and hardware layer to talk to each other and all of the code used to initialize the basic functions. Its usually contained on a nonvolatile memory (a chip) inside of the computer. Most commonly its some assembler (low level programming) code that talks to the chips and exposes their functionalities to the software. In order to actually boot the computer you needed a boot floppy disk or boot image on the hard drive.
WSG ROM
A quick overview on what are the functionalities of the most advance model of the Partners ROM (WFG).
selection of booting from a Floppy disk or from hard drive
procedures for printing the keyboard output to the GDP (graphical unit)
procedures for breakline operation (shift the screen content 12 pixels up, clear the bottom line, move the cursor to the left, enable the character print etc...)
memory test
hardware initialization
etc...
Content of the dumped ROMs
In the ROM dump there were two original ROMs for Iskra Delta Partner WFG, one Iskra Delta Partner unknown variant with Boss string and a couple of unknown ROMS, presumably character ROMs in YUSCII character set. Some of the chips have manufacturing date as late as 8841, meaning 41 week of 1988 so the EEPROMS had to be programed sometime after that.
The in depth comparison with original ROMs has not yet been done, but it's obvious that the "Boss rom" was altered/alternative WFG one. From the preliminary analysis it looks like either someone modified the original ROMs for unknown reasons, or this are ROMs containing development code ("watch out the boss is coming" could be internal jest). There is no way to confirm either theory, but it looks like an interesting part of the history nevertheless.
If you would like to take a look yourself I've published the dumps on GitHub:
Special thanks
I would like to specially thank Miha Grčar and Tomaž Štih for the information and help. If you're interested in Iskra Delta Partner, than I suggest to check out their github on homebrew software for this rare Slovenian computer: libcpm3-z80 , idp-dev