Previous Thread
Next Thread
Print Thread
Page 10 of 41 1 2 8 9 10 11 12 40 41
Joined: Jan 2012
Posts: 891
Likes: 17
C
Senior Member
Offline
Senior Member
C
Joined: Jan 2012
Posts: 891
Likes: 17
The DMAC can probably be removed from the machine config then. Can the owner confirm whether it has 80 track 5.25 floppy drives and if they are single or double sided?

Joined: Jan 2006
Posts: 3,691
Very Senior Member
Offline
Very Senior Member
Joined: Jan 2006
Posts: 3,691
Originally Posted by shattered
An owner of this machine confirmed that is has no DMAC. More dumps surfaced, I'll check them for dups & submit.

Also, with a bit of hackery, I got poisk1 to display something (wrong resolution, though). There's still a lot work to do (hook up the keyboard, at least):

[Linked Image from img-fotki.yandex.ru]

let me say that you're doing a great job here! smile

Joined: May 2012
Posts: 568
Likes: 10
S
Senior Member
OP Online Content
Senior Member
S
Joined: May 2012
Posts: 568
Likes: 10
Originally Posted by crazyc
The DMAC can probably be removed from the machine config then. Can the owner confirm whether it has 80 track 5.25 floppy drives and if they are single or double sided?


Asked him. Note, this is a 'pc-in-a-keyboard' machine, so the drive was external.

Pics: http://ru-oldpc.livejournal.com/26180.html

The specs in that post say that cassette interface had motor control (other clones don't have that luxury).

Joined: May 2012
Posts: 568
Likes: 10
S
Senior Member
OP Online Content
Senior Member
S
Joined: May 2012
Posts: 568
Likes: 10
Originally Posted by etabeta78
let me say that you're doing a great job here! smile


Thanks. This clone is unique among others -- its video controller is almost, but not quite, entirely unlike CGA: it doesn't use a mc6845, always runs in graphics mode, but you still can set a text mode via standard CGA ports. Any access to those (and video memory in text mode) causes a NMI, and its service routine does the rest.

Fortunately, there is BIOS source (that doesn't quite match the binaries) and technical manual (for a pre-release hardware) and a set of schematics (for two different hardware revisions).

Joined: Apr 2005
Posts: 616
Likes: 6
Senior Member
Offline
Senior Member
Joined: Apr 2005
Posts: 616
Likes: 6
+1 for the Douglas Adams reference laugh

Anyway, I love seeing news about these obscure Russian clones turning up recently. It's like a whole new world waiting to be uncovered (and emulated wink )

Joined: May 2012
Posts: 568
Likes: 10
S
Senior Member
OP Online Content
Senior Member
S
Joined: May 2012
Posts: 568
Likes: 10
Oh yeah, there are at least two more PC clones unemulated:

- Istra-4816 -- triple-CPU (8086 + 2x8080), could run DOS and/or CP/M (concurrently). I have some of its software but no dumps. Wiki: http://ru.wikipedia.org/wiki/%D0%98%D1%81%D1%82%D1%80%D0%B0-4816
- Neuron I9.66 -- uses Multibus instead of ISA.

Before IBM PCs, there were others:

- Iskra 226 -- said to be a clone/reimplementation of Wang 2200
- Electronika D3-28 -- likewise, of Wang 720

This hardware is rare enough my now, but software is nowhere to be found; f.e. apparently there was a port of V7 UNIX to Iskra 226.

Last edited by shattered; 05/12/13 09:48 AM.
Joined: May 2012
Posts: 568
Likes: 10
S
Senior Member
OP Online Content
Senior Member
S
Joined: May 2012
Posts: 568
Likes: 10
More WIP:

https://gist.github.com/shattered/5564625 softlist for mc1502
http://www.sendspace.com/file/990uey software

I had to hack wd_fdc.c, not sure how to do this cleaner. The reset routine (INT 13H AH=00) fails otherwise -- it waits for S_NRDY to clear and it never does.

How to use: press Enter twice after POST completes, at the '-' prompt enter '@'.

'ots' is a bad dump -- apparently the disk had 82 or more tracks, only 80 are dumped. It shows the logo, though.

'sfdos' is a good dump (it boots in ec1841), but doesn't boot here (fails to read 4 sectors starting at chs 0:1:6).

Joined: Jan 2012
Posts: 891
Likes: 17
C
Senior Member
Offline
Senior Member
C
Joined: Jan 2012
Posts: 891
Likes: 17
Quote
I had to hack wd_fdc.c, not sure how to do this cleaner. The reset routine (INT 13H AH=00) fails otherwise -- it waits for S_NRDY to clear and it never does.
Try commenting line 112 of wd_fdc.c and see if that fixes it (it fixed it for me but with an MS-DOS floppy).

Joined: May 2012
Posts: 568
Likes: 10
S
Senior Member
OP Online Content
Senior Member
S
Joined: May 2012
Posts: 568
Likes: 10
Apparently something changed in last two months, because the hack is no longer needed, but 'sfdos' still doesn't boot.

Joined: May 2012
Posts: 568
Likes: 10
S
Senior Member
OP Online Content
Senior Member
S
Joined: May 2012
Posts: 568
Likes: 10
asst128's BIOS I uploaded is not original, it was modified twice (once by whoever designed the 3rd-party floppy interface, and then by the owner). Second change NOP's this block of code:

-000FE1EE: BA 01 01 mov dx,101h
-000FE1F1: E8 14 03 call 0FE508h
-000FE1F4: FA cli
-000FE1F5: F4 hlt



Page 10 of 41 1 2 8 9 10 11 12 40 41

Link Copied to Clipboard
Who's Online Now
3 members (Cpt. Pugwash, 2 invisible), 196 guests, and 1 robot.
Key: Admin, Global Mod, Mod
ShoutChat
Comment Guidelines: Do post respectful and insightful comments. Don't flame, hate, spam.
Forum Statistics
Forums9
Topics9,320
Posts121,923
Members5,074
Most Online1,283
Dec 21st, 2022
Our Sponsor
These forums are sponsored by Superior Solitaire, an ad-free card game collection for macOS and iOS. Download it today!

Superior Solitaire
Forum hosted by www.retrogamesformac.com