Re: [N8VEM: 3548] Re: Soviet Computer (Re: My N8VEM - up and running)

[James Moxham <mox...@internode.on.net>]

Tape storage. Yes, fond memories there. Mainly of waiting. And waiting...

The CRT display could be relevant to what Andrew is working on. I don't 
know if Andrew is building a display for a TV output or for a VGA. Or both?

CP/M with a ramdisk? Sounds like the N8VEM!

Keyboard - yes standard matrix of keys. These days, you can pick up a 
PS/2 keyboard for $3 and it only uses 4 lines on an 8255 and a few lines 
of 8080/Z80 machine code, so keyboards are a lot easier now. But there 
is something great about programming with push buttons in hex. Almost as 
tedious as programming with toggle switches.

Sergey wrote:
> The system came with a monitor program in EPROM that allowed: loading/
> saving memory content from/to tape; viewing/modifying memory contents
> (in hex); checksumming memory contents; jumping to an address in
> memory, etc.
> In magazine you have the dump of the monitor EPROM (issue 8/86, page
> 24). So one who builds the system can program it. I think that I also
> saw a switch-based EPROM programmer in one of these magazines.
> Another dump is a test program (issue 7/86, page 27). I think it
> supposed to scan all memory locations, or something like that, so you
> can debug the system with an oscilloscope or a logic probe. It also
> contain schematics for step-by-step execution circuit.
> All other software also was published as hex dumps with checksums for
> each kilobyte block or so.
>
> A floppy disk drive was a rare and hard to get thing, so all home-made
> designs used tape recorder for storage. At least UT-88 documentation
> mentions that it's possible to use CP/M using a ramdisk for storage.
>
> The software that came with my system was supplied on two tapes
> (cassettes), I think that one tape contained editor/assembler/basic
> and probably some other applications and development tools and the
> other one contained games.
>
> BTW, here is the schematics for CRT and keyboard controller for UT-88
> system: http://junetech.chat.ru/kollection/ut88/ris54_big.jpg
> As you can see, it doesn't use any special CRT controller ASIC (apart
> of an i8255 used for keyboard interface). The description in Russian
> is available here: http://junetech.chat.ru/kollection/ut88/display.htm
> You can use http://translate.google.com to translate it to English (I
> tried it, it gives a kind of "Chinese" English, but you can understand
> the idea).
> According to the documentation it provided 64 columns x 28 lines
> alphanumeric display with 7x5 characters and had some scrolling
> functionality. The output is a composite B/W video signal (50Hz
> horizontal sync), which could be connected to any PAL/SECAM TV. The RF
> modulator schematics is provided at the bottom of the page - in case
> TV doesn't have composite input (and many older TV's in Soviet Union
> didn't had that).
>
> Thanks,
> Sergey
>
>
> On May 22, 5:31 am, "James Moxham (Dr_Acula)"
> <mox...@internode.on.net> wrote:
>   
>> What sort of operating system did this run? I can see some references
>> in the text to where programs were loaded in hex. Was there something
>> like CP/M?
>>     
> >
>
>