Ghosts in the wires

It is up. The repository is public. It went out twelve minutes after midnight on Saturday, which is not an hour anybody picks, and then I sat there and found three more things wrong with it. All three are in the log with timestamps after the thing was already public: a sector count that had been wrong since May, a README still quoting a line count I had disproved myself, and three findings notes that said what I no longer think. The tag went on at half past one, and I was on the road east by two. There is a page for the project too, with the pictures.

What is in it: six disk sides, the reader that turns them back into files, the eight interpreter builds that were sitting on the boot pages between 1981 and 1986, the listings, and the part I am proud of, which loads a program off an image and runs it. Twenty-three of twenty-three findable programs load and run without falling over. Payroll arithmetic from 1989 comes out on my screen and matches what I get on paper.

Now the sentence that has to sit next to that one. It runs the software, not the processor. The interpreter firmware from those boot pages does not execute. My own code stands in for it and reads the programs the way it would have, and none of this touches real hardware anywhere. That is the whole distance between what I have and a finished emulator, and I would rather measure it myself than have somebody do it for me.

The distance is long. Forty-nine arithmetic and logic instructions are still undecoded, and the D-class addressing goes with them. Around fifty-eight percent of the machine level is unknown to me. Worse, the biggest missing piece was never on a floppy at all: the Iskra's own ПЗУ, the read-only store the machine came up out of. Nobody has put one online that I can find, and the sources that mention its size do not agree with each other. The microprogram store is missing the same way, two thousand words of sixteen bits.

So this is a request, and I mean it plainly. If you have a board photograph, a service manual, a read of a ROM, an eight-inch disk in a box from an office that stopped existing, write to me. Mirror the images so they survive me. Six of those sides are not my doing; two people I have never met, vazman and dk_spb, put them where I could find them.

Somebody asked me in Riga what a novelist wants with a dead Soviet computer. In my books I wake the ghosts of the Soviet past. In my code I wake the ghosts in the wires. The second kind answers, which is new to me, and I am not finished asking.