MiSTer FPGA Forum

RedskullDC wrote: ↑Thu Oct 14, 2021 7:53 am Hi DanielB, et al.

danielb wrote: ↑Thu Oct 14, 2021 6:06 am I really need to find out exactly what the differences were between the UK101 and the OSI machines, and also the differences between the different OSI models,

Main differences:

Default Screen size: UK101 = 48x16, OSI C1p = 32x32, OSI c2,c3,c4,c8 = 32x32 or 64x32
(Normally 24x24 would be visible with a C1p, as it doesn't account for the front/back porch area in the video signal).
32x32 mode on the C1p is addressed differently to that on the bigger end models too.

Keyboard addressing:
UK101 and OSI C1p are the same.
OSI C2,C3,C4,C8 all have the bits inverted. (Check my keyboard code)

Monitor roms:
Different variations of the monitor. Individual 256 byte routines can be addressed anywhere between $F000 and $FFFF in the bigger models.
This is a minefield
check out the discussions on this topic in the forums at osiweb.org

ACIA addressing.
Large models have the serial/parallel chips addressed at different locations to the C1p/UK101.
Again, this doesn't help compatibility between OSI models at all.

Probably a few other minor things, but nothing of note I don't think.
Manuals for all models are on osiweb.org

Hope that helps.

Red

danielb wrote: ↑Wed Oct 13, 2021 8:05 pm

EeDee wrote: ↑Wed Oct 13, 2021 6:50 pm

danielb wrote: ↑Fri Oct 08, 2021 3:42 pm
- Floppy disk system. This would be very difficult, at least for me. To do this, you would need precise documentation of the actual interface, and the original DOS ROMS. Some of this does exist for the Superboard, but even so, I suspect this is beyond my FPGA coding skills. There are some disk images on the web for the Superboard, but I don't know whether they would even theoretically work on the UK101.

Not just for you I think: https://stardot.org.uk/forums/viewtopic.php?t=13550 (3rd post down and Link in the last one)

Wow, there are some pretty hardcore UK101 people on that forum

Meanwhile I have been messing about with the OSI emulator on this site http://osi.marks-lab.com/index.php. It supports the UK101, and several different models of OSI computer. It also comes packaged with quite a lot of software, including disk images. My original intention was to try to use the emulator to export files from the disk images and see if I could get them to run on the core. I was able to export a couple of files, but they were for a more advanced OSI model and didn't run properly.

This got me wondering what it would take to get them running...

D.

EeDee wrote: ↑Thu Oct 14, 2021 10:55 am

danielb wrote: ↑Wed Oct 13, 2021 8:05 pm

EeDee wrote: ↑Wed Oct 13, 2021 6:50 pm

Not just for you I think: https://stardot.org.uk/forums/viewtopic.php?t=13550 (3rd post down and Link in the last one)

Wow, there are some pretty hardcore UK101 people on that forum

Meanwhile I have been messing about with the OSI emulator on this site http://osi.marks-lab.com/index.php. It supports the UK101, and several different models of OSI computer. It also comes packaged with quite a lot of software, including disk images. My original intention was to try to use the emulator to export files from the disk images and see if I could get them to run on the core. I was able to export a couple of files, but they were for a more advanced OSI model and didn't run properly.

This got me wondering what it would take to get them running...

D.

Read this:
"The 40 pin expansion socket opened up the world to the UK101. It also mated with all Superboard extras. One could attach a dual 5.5-inch floppy disk controller and a memory expansion card (40K max) to allow faster and reliable save/load of programs/data. Later on Compshop recommended not using discs with the UK101. The original intention was to use Ohio Scientific discs, however they were made to work with the original version but did not work with later versions."
Here: http://www.computinghistory.org.uk/det/ ... UK101-(2)/

EeDee wrote: ↑Thu Oct 14, 2021 8:11 am @RedskullDC
You seem to have an interest in this line of computers

RedskullDC wrote: ↑Thu Oct 14, 2021 2:58 pm Hi EeDee, et al.

EeDee wrote: ↑Thu Oct 14, 2021 8:11 am @RedskullDC
You seem to have an interest in this line of computers

Yes, you could say that

The OSI Superboard II was the first machine I bought as a school kid way back when.

Currently have a Suberboard II, C1P + 610 expansion board, and a C4P built with reproduction PCBs.

(User "glitchwrks" makes the repro boards: https://www.ebay.com.au/sch/glitchwrks/m.html)

Cheers,
Red

danielb wrote: ↑Thu Oct 14, 2021 7:23 pm After a little bit of fiddling, I managed to hack together a version of the core that runs OSI Basic, and uses the OSI character set. It runs OSI Invaders, showing off the correct characters.
At this stage, I made no changes to the screen resolution, and it's running the same monitor as before.
It's pretty hilarious that all the characters are reversed, until you reverse them back.

D.

danielb wrote: ↑Sat Oct 16, 2021 8:19 am Hi,

Here is another pre-release version.

This one allows switching between UK101 and OSI machines.

Compatibility with UK101 games seems to be the same as before.

Tested OSI games include Galaxia, Pacdude, OSIInvaders, SuperDefender, Universe, TimeTrek, Pinball and OSI Grand.

Caterpillar and RidgeCruiser do not work. NightRider seems to work with glitches.

OSI mode is only 64x32 ATM. This is what the ROM seems to want to default to, and I don't yet have a 32x32 or 24x24 mode.

D.

danielb wrote: ↑Sun Oct 17, 2021 7:26 pm Hi all,

I managed to get 32-column mode to work. Not quite ready for the big time yet, but coming soon.

Using the same principle, I could add other resolutions, like 32x16 (already working...), 48x32 or whatever. Is there any use for these?

D.

EeDee wrote: ↑Sun Oct 17, 2021 7:43 pm

danielb wrote: ↑Sat Oct 16, 2021 8:19 am Hi,

Here is another pre-release version.

This one allows switching between UK101 and OSI machines.

Compatibility with UK101 games seems to be the same as before.

Tested OSI games include Galaxia, Pacdude, OSIInvaders, SuperDefender, Universe, TimeTrek, Pinball and OSI Grand.

Caterpillar and RidgeCruiser do not work. NightRider seems to work with glitches.

OSI mode is only 64x32 ATM. This is what the ROM seems to want to default to, and I don't yet have a 32x32 or 24x24 mode.

D.

Thanks. There are a couple of OSI games (Aardvark Berrrzerrk and Blockade) working which didn't, properly, on the 101.

danielb wrote: ↑Sun Oct 17, 2021 7:26 pm Hi all,

I managed to get 32-column mode to work. Not quite ready for the big time yet, but coming soon.

Using the same principle, I could add other resolutions, like 32x16 (already working...), 48x32 or whatever. Is there any use for these?

D.

danielb wrote: ↑Wed Oct 20, 2021 4:14 pm Hi,

OSI mode is now "official". In addition to this, input files may now have the .bas and .lod extensions, which seem to be fairly standard for Basic and machine code programs.

@Eedee: I was wondering what the Multicomp was based on, although it seems to be a less precise simulation than the UK101-specific one. The Z80 Multicomp is apparently based on the Nascom, which is another machine that it might be worth porting to the MiSTer.

D.

EeDee wrote: ↑Wed Oct 20, 2021 6:37 pm I've been trying the WinOSI Emulator. Feature rich or what?! It's great! Much prefer the Mister version though for some reason or other
Thanks again. I'm going to give it a try now

danielb wrote: ↑Wed Oct 20, 2021 7:56 pm It's great for giving an idea of what's possible and how it should work.

I was very happy to see that a couple of games that don't work on the core, don't work on the emulator either.

The only game that does work on the emulator, and should, as far as I know, work on the core, but doesn't, is Caterpillar. Not sure what's going on there...

BTW, I found this: https://archive.org/details/OSI_Aardvar ... s/mode/2up. It's a very interesting little historical document about a game that does run on the core. I especially like "don't look at the screen while the game is loading"

D.

danielb wrote: ↑Wed Oct 20, 2021 7:56 pm The only game that does work on the emulator, and should, as far as I know, work on the core, but doesn't, is Caterpillar. Not sure what's going on there...

EeDee wrote: ↑Wed Oct 20, 2021 9:51 pm

danielb wrote: ↑Wed Oct 20, 2021 7:56 pm The only game that does work on the emulator, and should, as far as I know, work on the core, but doesn't, is Caterpillar. Not sure what's going on there...

At the end of data input it just stops. If you press the space bar you can make out HIT P TO START but that's about it

danielb wrote: ↑Wed Oct 20, 2021 9:56 pm Add a carriage return to the end of the file. It will then clear the screen, say "Hit p to start" and freeze.

D.

EeDee wrote: ↑Thu Oct 21, 2021 8:15 am

danielb wrote: ↑Wed Oct 20, 2021 9:56 pm Add a carriage return to the end of the file. It will then clear the screen, say "Hit p to start" and freeze.

D.

Yes it does
Any idea what is involved in getting it to load archived files?