The monitor has enough code to say read the first n sectors of disk into memory (it already has the command stubs in the monitor program). It is not much code to do that as the propeller is a smart disk controller. Then you jump to CPM. The loader effectively does this in the N8VEM today.
Heater:
If you look at the SIMH code and documentation it does more than just Altair simulation. You can invoke parameters to handle different disk controllers, you can emulate different systems like cromemco, compupro, and even N8VEM. The cpm disks I grant you are built for Altair. But if we come to common ground we can add to the simulator the common simulation model we build so that we can make disks that run across the 4 platforms I suggested. It would be minor ifdefs to the Altair CBIOS, but in exchange for doing that we can make disk images that will boot and run on SIMH, ZiCog-Triblade, NV8EM + propIO, and ZiCog - Morpheus (I think). What we give up is running on the SIMH with stock Altair mode. Though by just changing ifdef you can get back to that mode. With just a few changes we can have 4 platforms with common everything vs now we only have 2 by sticking with pure Altair CBIOS.
1) We hack our CBIOS around such that can support a common ZiCog, PropIO, Morpheus, Hydra whatever Propeller + SD card based systems. Such that disk images are transferable between them and and bootable by all of them.
2) That BIOS is based on the SIMH Altair Z0 BIOS with some "ifdefs" to compile for Propeller systems. So we can get rid of skew and 137 byte sectors, add other optimizations and move the IO ports to a range that PropIO can decode etc.
3) SIMH would then get a new simulation model added for this new CBIOS-hardware interface say ZPMH just like it has for N8VEM.
4) SIMH would get new disk driver modules.
Am I right so far?
I must say this looks like a lot of work! Who would create the SIMH emulation model for ZPMH and the new SIMh disk driver module?
Would we not loose the ability to take a cpm2 disk off the SIMH site and just boot it after a simple sector transformation?
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For me, the past is not over yet.
Just my quick 2cents worth (I am driving back to Sydney-Gosford) tomorrow w Tribladhe hw YIPEE :_)
I believe the CPM2.2, CPM3, MPM SIMH disk/files with just the reformat to convert from 137 byte sectors to 128 sectors (packed to 4x128) should be all that is required. If the prop requires a boot binary, then that is acceptable to me. BUT the disk files should be identical. They work now. It just whether we want 128 per 512 or 4x128 per 512 SD sectors. So simple transformation only.
As for N8VEM, ZiCog should be able to simulate the N8VEM hardware.
Heater is correct. The Drive_1M.DSK is actually 64KB CPM code to be loaded into ram and a 1MB floppy (previous code function). ZiCog/TriBlade now only loads the boot section ($FF00-FFFF) from the 64KB image, so that could be contained within the ZiCog boot code (eeprom). But it is my intention (and it has already be proven to work) to allow the Prop to boot ZiCog - be it CPM2.2, CPM3, MPM or PropDos or whatever is offered within the prop world. This maybe a timed default or boot code provided on the SD card. This should have no impact on the N8VEM SDdrive except that extra prop binary boot files MAY exist on the SD card for alternative prop booting. This will be an extra, not a replacement.
Hope this adequately explains my thoughts on the projects
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ Links to other interesting threads:
I will take a stab at SIMH and disk driver module. Because I have all 4 of these platforms and will have #5 when Cluso finishes the RAM Blade, it is more important to me to have interoperability between these 4 or 5 platforms than to maintain 100% compatibility with the Altair System.
On your question about taking a cpm disk from SIMH there is a multitude of ways to accomplish. 1) copy our CBIOS to disk on SIMH and do syscpm2 to rewrite the boot tracks or just not make that the bootable disk in the emulated disks and re write the boot tracks on imported disk.
Remember with SIMH - there will be an option for our new emulator model and the original Altair mode is still there so you can boot it either way.
I don't think the SIMH changes will be too hard, I can start on them this weekend probably.
What we need to decide is I/O ports and what our disk controller model will look like. I was thinking that the hdDisk driver in SIMH is pretty good. If we change just to define to have static DPH/DPB for hard drives then I think we could use the same controller for both floppies and hard drives. Then we could use DMA for floppies on the triblade and Morpheus.
I need to look at memory bank latch on N8VEM as that will be something fixed that I can't change and we need to emulate that in SIMH and triblade, morpheus. SIMH already supports that for the N8VEM so I will yank that code into the new module.
There has been a lot of activity on the N8VEM mailing list on the DiskIO board. The FDC CBIOS is maturing and bringing with it some issues of how to deal with booting and many of the discussions we've been having here. Rather than repeat the entire discussion here, I will post a link to the N8VEM mailing list so you can see the discussion.
I would very much like to coordinate this with the Propeller community to maintain some compatibility across N8VEM, Triblade, PropIO, etc. My post is only my personal view to help the discussion along not a direction that is "cast in stone".
There is a capability to mount N8VEM formatted floppy disks on PCs using the 22DISK program. Likewise the floppy disks can be converted to an image file using the Dave Dunfield IMD program which are directly usable in SIMH.
I've asked Howard Harte to help us extend the N8VEM SIMH emulation to support DiskIO operations and I think the same could be done for PropIO as well.
I recognize this brings an added level of complexity to the discussion but these are well established protocols in the vintage/classic/home brew computer community and it would be ideal if Propeller could support them as well. Since the ZiCog is already there with its emulation these would be extensions bringing Propeller more fully "into the fold" of the larger community.
Please consider and I will answer any questions I can. Thanks and have a nice day!
Comments
The monitor has enough code to say read the first n sectors of disk into memory (it already has the command stubs in the monitor program). It is not much code to do that as the propeller is a smart disk controller. Then you jump to CPM. The loader effectively does this in the N8VEM today.
Heater:
If you look at the SIMH code and documentation it does more than just Altair simulation. You can invoke parameters to handle different disk controllers, you can emulate different systems like cromemco, compupro, and even N8VEM. The cpm disks I grant you are built for Altair. But if we come to common ground we can add to the simulator the common simulation model we build so that we can make disks that run across the 4 platforms I suggested. It would be minor ifdefs to the Altair CBIOS, but in exchange for doing that we can make disk images that will boot and run on SIMH, ZiCog-Triblade, NV8EM + propIO, and ZiCog - Morpheus (I think). What we give up is running on the SIMH with stock Altair mode. Though by just changing ifdef you can get back to that mode. With just a few changes we can have 4 platforms with common everything vs now we only have 2 by sticking with pure Altair CBIOS.
Dave
You are proposing that:
1) We hack our CBIOS around such that can support a common ZiCog, PropIO, Morpheus, Hydra whatever Propeller + SD card based systems. Such that disk images are transferable between them and and bootable by all of them.
2) That BIOS is based on the SIMH Altair Z0 BIOS with some "ifdefs" to compile for Propeller systems. So we can get rid of skew and 137 byte sectors, add other optimizations and move the IO ports to a range that PropIO can decode etc.
3) SIMH would then get a new simulation model added for this new CBIOS-hardware interface say ZPMH just like it has for N8VEM.
4) SIMH would get new disk driver modules.
Am I right so far?
I must say this looks like a lot of work! Who would create the SIMH emulation model for ZPMH and the new SIMh disk driver module?
Would we not loose the ability to take a cpm2 disk off the SIMH site and just boot it after a simple sector transformation?
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
For me, the past is not over yet.
I believe the CPM2.2, CPM3, MPM SIMH disk/files with just the reformat to convert from 137 byte sectors to 128 sectors (packed to 4x128) should be all that is required. If the prop requires a boot binary, then that is acceptable to me. BUT the disk files should be identical. They work now. It just whether we want 128 per 512 or 4x128 per 512 SD sectors. So simple transformation only.
As for N8VEM, ZiCog should be able to simulate the N8VEM hardware.
Heater is correct. The Drive_1M.DSK is actually 64KB CPM code to be loaded into ram and a 1MB floppy (previous code function). ZiCog/TriBlade now only loads the boot section ($FF00-FFFF) from the 64KB image, so that could be contained within the ZiCog boot code (eeprom). But it is my intention (and it has already be proven to work) to allow the Prop to boot ZiCog - be it CPM2.2, CPM3, MPM or PropDos or whatever is offered within the prop world. This maybe a timed default or boot code provided on the SD card. This should have no impact on the N8VEM SDdrive except that extra prop binary boot files MAY exist on the SD card for alternative prop booting. This will be an extra, not a replacement.
Hope this adequately explains my thoughts on the projects
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Links to other interesting threads:
· Home of the MultiBladeProps: TriBladeProp, RamBlade, TwinBlade,·SixBlade, website
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator)
· Prop Tools under Development or Completed (Index)
· Emulators: Micros eg Altair, and Terminals eg VT100 (Index) ZiCog (Z80) , MoCog (6809)
· Search the Propeller forums·(uses advanced Google search)
My cruising website is: ·www.bluemagic.biz·· MultiBladeProp is: www.bluemagic.biz/cluso.htm
I will take a stab at SIMH and disk driver module. Because I have all 4 of these platforms and will have #5 when Cluso finishes the RAM Blade, it is more important to me to have interoperability between these 4 or 5 platforms than to maintain 100% compatibility with the Altair System.
On your question about taking a cpm disk from SIMH there is a multitude of ways to accomplish. 1) copy our CBIOS to disk on SIMH and do syscpm2 to rewrite the boot tracks or just not make that the bootable disk in the emulated disks and re write the boot tracks on imported disk.
Remember with SIMH - there will be an option for our new emulator model and the original Altair mode is still there so you can boot it either way.
I don't think the SIMH changes will be too hard, I can start on them this weekend probably.
What we need to decide is I/O ports and what our disk controller model will look like. I was thinking that the hdDisk driver in SIMH is pretty good. If we change just to define to have static DPH/DPB for hard drives then I think we could use the same controller for both floppies and hard drives. Then we could use DMA for floppies on the triblade and Morpheus.
I need to look at memory bank latch on N8VEM as that will be something fixed that I can't change and we need to emulate that in SIMH and triblade, morpheus. SIMH already supports that for the N8VEM so I will yank that code into the new module.
Comments???
Dave
There has been a lot of activity on the N8VEM mailing list on the DiskIO board. The FDC CBIOS is maturing and bringing with it some issues of how to deal with booting and many of the discussions we've been having here. Rather than repeat the entire discussion here, I will post a link to the N8VEM mailing list so you can see the discussion.
I would very much like to coordinate this with the Propeller community to maintain some compatibility across N8VEM, Triblade, PropIO, etc. My post is only my personal view to help the discussion along not a direction that is "cast in stone".
http://groups.google.com/group/n8vem/browse_thread/thread/456b792a5643f087
Thanks and have a nice day!
Andrew Lynch
As you can see here
http://groups.google.com/group/n8vem/browse_thread/thread/afbda438fa3b46eb/047038e68eacb9ae?lnk=gst&q=SIMH#
There is a capability to mount N8VEM formatted floppy disks on PCs using the 22DISK program. Likewise the floppy disks can be converted to an image file using the Dave Dunfield IMD program which are directly usable in SIMH.
I've asked Howard Harte to help us extend the N8VEM SIMH emulation to support DiskIO operations and I think the same could be done for PropIO as well.
I recognize this brings an added level of complexity to the discussion but these are well established protocols in the vintage/classic/home brew computer community and it would be ideal if Propeller could support them as well. Since the ZiCog is already there with its emulation these would be extensions bringing Propeller more fully "into the fold" of the larger community.
Please consider and I will answer any questions I can. Thanks and have a nice day!
Andrew Lynch
http://groups.google.com/group/n8vem/browse_thread/thread/456b792a5643f087
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Links to other interesting threads:
· Home of the MultiBladeProps: TriBladeProp, RamBlade, TwinBlade,·SixBlade, website
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator)
· Prop Tools under Development or Completed (Index)
· Emulators: Micros eg Altair, and Terminals eg VT100 (Index) ZiCog (Z80) , MoCog (6809)
· Search the Propeller forums·(uses advanced Google search)
My cruising website is: ·www.bluemagic.biz·· MultiBladeProp is: www.bluemagic.biz/cluso.htm