ROM Dubna-48k
ZXNet echo conference «hardware.zx»
Hello, [bETA]mEN
bET> mEN']Like it:
It doesn't look like it.
The only difference from the standard firmware is the command:
┌─- CODE ───
LD a,8Bh
OUT(0DEh),a
└── CODE ───
Looks like initializing port 580BB55.
Inserted into the Basic startup procedure.
The rest is standard, only zeros are scattered in the free memory zone.
Hello caro
It would be better to use the Hacker-2000 ROM
Hello, Jukov
The Dubna ROM is very different from the standard one (because the processor is instead of 3.5 MHz
operates at almost 2 times lower frequency), Kempston port of the joystick and
keyboard is implemented on 580ВВ55А, since the CPU frequency is non-standard, then in
ROM procedures for working with a tape recorder have adjusted timings (so that
writing/reading went at normal speed). For the same reason they don't work
non-standard bootloaders (those that do not use fragments from the ROM, for example
as in zynaps or uridium).
In general, we talked about this computer (in personal correspondence) with conan, who also
I handed over a scanned diagram and a book describing the computer.
Hello deathsoft
dea> In general, we talked about this computer (in personal correspondence) with
dea> conan, I gave him the scanned diagram and a book with a description
dea> computer.
I already received this book from him :)
I would just like to have ROM firmware as well.
Hello Alchemist
Alc> I would just like to have ROM firmware as well
I have this computer in stock, the problem is that the ROMs are soldered into the board
(2 pieces of RF), so it’s not possible to take a dump with a programmer without desoldering (the machine is
working), it is only possible to write the ROM to a PC via a Sound card using save ""
code 0.16384. The problem is that I don’t even have anything to connect this dubna to
(only if you have a TV tuner on your computer)
Hello deathsoft
I shot the Dubna ROM image into a wav file (16bit 44100), the file weighs 8MB, which is more than it can be
convert to tap or tzx?
Hello deathsoft
dea> Thanks for the link, I looked it up and immediately found it in my archive
dea> maketzx utility downloaded from World of Spectrum. File from ROM converted
dea> and am posting the binary for anyone who is interested.
Thank you!
Hello deathsoft
dea> I converted the file from the ROM and am posting the binary for everyone
dea> interesting.
Differences from standard Basic 48:
1) The NMI execution procedure is clogged with code 0xFF;
2) All constants in LOAD and SAVE are reduced by 2 times;
3) The command to initialize the BB55 port was inserted;
4) The opening screensaver has been changed to "DUBNA 1988".