Is the propeller fast enough? I had thought about that as well initially, but wasn't sure if you could get the timing down. You have to make sure you don't accidentally cause bus-contention or data corruption by driving the bus when you aren't supposed to (or stop driving it prematurely). How long does it take for a PASM instruction execute if the chip is running at 80 mhz?
At 80MHz and 4 clocks per PASM instruction 50ns. The MOSTEK Z80 manual I have indicates a high and low times of 180ns and allowing for rise/fall times say 400ns per clock (2.5MHz). So 8 PASM instructions per Z80 clock. Hmm might be sticky. But then one can always drive the WAIT signal quickly and then take your time. Or as others have suggested, drive the Z80 clock from the Propeller!
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For me, the past is not over yet.
Introducing the worlds first single chip CP/M computer!
Please find attached a build of PropAltair with a 20K CP/M system using the Keyboard and TV_Text drivers. Should also work with VGA_Text.
I believe this makes it the worlds first complete CP/M computer in a single chip. Not counting the EPROM which I don't actually have in my board anyway.
Problem is neither do I have a TV that will take composite video or a VGA monitor, only lap tops here. So I have no idea if this works !!
Could some kind soul please load this onto a PropDemo board or such and tell me what happens? A screen shot would be nice. If you already have a CP/M image on an SD card no need to update it.
The first person to do this wins the prize of, well, being the first person in the world to witness the worlds first CP/M computer running [noparse];)[/noparse]
Yeah, yeah I know, you still need a screen full of chips, but the first CP/M computers did not include screens or keyboards only serial I/O. Mmmm...In that case PropAltair already was first.
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For me, the past is not over yet.
I have run the TV version - it works (I'm not so surprised, because going from PC_Text to TV_Text should always work [noparse];)[/noparse]
But it is not really usable with 40 characters per line.
So I have tried some VGA Text versions: 64*48 with ROM font fits with the PC_Keyboard, but not with the PS/2 keyboard (80 longs to big).
The 80*40 VGA text driver is to big, because it has the font in RAM - perhaps a 18kByte CPM will work.
Attached 3 pictures, a really bad from TV, and 2 from VGA with 64*48 characters.
I have made some modifications to your PropAltair 2.4 :
The modifications allow to have the CPM2.DSK file on the SD card within a FAT16 file system as
a normal file. You simply can copy the 4 MByte Disk image to the SD card, with a card reader. No
need to download it with PropTerminal. And you can copy it back to the PC Harddisk after writing
new files to the Altair disks to keep this changes.
It is important, that this big file has contiguous sectors, this is normally the case, if it is
written with Windows and a card reader (I hope not only on my WinXP system).
Set up an Altair system:
1) Download PropAltair 2.4 and extract it.
2) Rename cpm2.dsk to cpm2.old or so, if you will keep it for later.
2) Copy the files from attached ZIP into the same directory (cpm2.dsk will be replaced).
3) Copy cpm2.dsk to the SD card with a card reader.
4) Start first 'disk_sector.spin' and note the found start sector.
5) Edit 'altair_sim_25.spin'. Set clock, and SD card settings, and START_SECTOR = <found sector above>
6) Run the PropTerminal from the Altair directory, edit COM port if necessary, and minimize it.
7) Start 'altair_sim_25.spin' with F10 and when uploaded, restore PropTerminal quickly (click in the Taskbar).
8) use CP/M and have fun...
Congratulations Ariba! And thank you, most encouraging.
I could go to an 18K CP/M but unless anyone is desperate I'm going down to 16K which will make room for PropComm for it's VT100 emulation.
I had wondered about that idea of burying the disk image in a DOS file system while not actually using FAT code in the emulator. At the time I could not be sure the file would always be contiguous and I had no card reader anyway, still don't.
Now that I want to add simulated hard disks, 4 times 8Mbytes, this trick becomes very important. Time for me to get a card reader.
Ariba could you extend this to handle up to 8 floppy disk images and 4 hard disks, say: fd_a.dsk, fd_b.dsk ... fd_h.dsk, hd_i.dsk ... hd_l.dsk?
Cluso, waiting with great anticipation. There is no place to put external RAM driver code in PropAltair, I have to get on with multi COG emulator.
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For me, the past is not over yet.
In case anyone is wondering. PropAltair is not dead despite the new and improved ZiCog Z80 emulator. It will continue along these lines:
1. Upgrade to an 8080 only version of the ZiCog emulation. The accurate 8080 emulation will be called iCog.
2. Hardware will no doubt be Cluso's TriBlade board.
3. The big missing piece - The Altair front panel with all the switches and blinken lights !
Fortunately the TriBlade has a third Prop free to drive item 3.
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For me, the past is not over yet.
Toby, do I detect a note of sarcasm there? You might be surprised at what could be done with a 2MHz 8080 and tight assembly coding. I ran a business on such a system for several years and generated invoices, po's, quotes, letters etc., as well as schematic capture and PCB layout. With Magic Wand, Supercalc, and Dbase you could accomplish almost everything you needed to run a business.
Not sarcasm, just needless exageration. I am at work and bored to the core.
I, probably more than most, am still nursing the beleif that because I could do Z80 machine code it made me an expert. It was true back in the 70's, but not now, Hey-Ho. Rest assured I bow to the efforts shown on these projects, they might make it possible for me, to appear, to know something about someting, again.
@Toby
You are right "Upgrade to an 8080..." does not make much sense to the uninitiated. Thing is the ZiCog emulator is faster than my old 8080 only PropAltair emulator code. It is a more accurate emulation concerning flag setting. It is also a lot easier to understand and modify, for use with external RAM for example. So it is actually an upgrade in this context.
Anyway, it is not clear to me that moving to the Z80 instruction set on real silicon was much of an upgrade, only a few of the instructions gained you any speed. Most people seemed to realize that and kept away from 99% of the Z80 ops. The chip itself was faster and easier to integrate into systems though.
Never underestimate the power of an abacus. Needs no batteries, has non-volatile store, intuitive "What You See Is What You Get" interface. I can calculate square roots on an abacus.
For sure if you know Z80 assembler you are an "expert". That knowledge and understanding is transferable to pretty much all assembly languages, they are still in use today. It's a step toward becoming a compiler writer, an OS kernel writer.... The bounds are limitless.
@kwinnn
"schematic capture and PCB layout" What ? How? Id like to see the software that did that.
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For me, the past is not over yet.
This post marks the passing away of Dr. Henry Edward Roberts creator of the MITS Altair computer in 1975.
Too bad this post went pretty much unoticed.·My Dad bought·Altair 8800 serial #175 and he and I soldered it up in 1975. The best father/son project I ever worked on.
I keeped it with me though many moves, but sold it on ebay in 2001. Still miss it, but it brought $3,500 when I·needed money.·Cost was $385.00 in 1975, if I recall, the 8080 CPU was about $175.00 of the cost.
Dr. Roberts was a unsung hero in my book.
heater said...
This post marks the passing away of Dr. Henry Edward Roberts creator of the MITS Altair computer in 1975.
Comments
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For me, the past is not over yet.
Please find attached a build of PropAltair with a 20K CP/M system using the Keyboard and TV_Text drivers. Should also work with VGA_Text.
I believe this makes it the worlds first complete CP/M computer in a single chip. Not counting the EPROM which I don't actually have in my board anyway.
Problem is neither do I have a TV that will take composite video or a VGA monitor, only lap tops here. So I have no idea if this works !!
Could some kind soul please load this onto a PropDemo board or such and tell me what happens? A screen shot would be nice. If you already have a CP/M image on an SD card no need to update it.
The first person to do this wins the prize of, well, being the first person in the world to witness the worlds first CP/M computer running [noparse];)[/noparse]
Yeah, yeah I know, you still need a screen full of chips, but the first CP/M computers did not include screens or keyboards only serial I/O. Mmmm...In that case PropAltair already was first.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
For me, the past is not over yet.
I have run the TV version - it works (I'm not so surprised, because going from PC_Text to TV_Text should always work [noparse];)[/noparse]
But it is not really usable with 40 characters per line.
So I have tried some VGA Text versions: 64*48 with ROM font fits with the PC_Keyboard, but not with the PS/2 keyboard (80 longs to big).
The 80*40 VGA text driver is to big, because it has the font in RAM - perhaps a 18kByte CPM will work.
Attached 3 pictures, a really bad from TV, and 2 from VGA with 64*48 characters.
Andy
I have made some modifications to your PropAltair 2.4 :
The modifications allow to have the CPM2.DSK file on the SD card within a FAT16 file system as
a normal file. You simply can copy the 4 MByte Disk image to the SD card, with a card reader. No
need to download it with PropTerminal. And you can copy it back to the PC Harddisk after writing
new files to the Altair disks to keep this changes.
It is important, that this big file has contiguous sectors, this is normally the case, if it is
written with Windows and a card reader (I hope not only on my WinXP system).
Set up an Altair system:
1) Download PropAltair 2.4 and extract it.
2) Rename cpm2.dsk to cpm2.old or so, if you will keep it for later.
2) Copy the files from attached ZIP into the same directory (cpm2.dsk will be replaced).
3) Copy cpm2.dsk to the SD card with a card reader.
4) Start first 'disk_sector.spin' and note the found start sector.
5) Edit 'altair_sim_25.spin'. Set clock, and SD card settings, and START_SECTOR = <found sector above>
6) Run the PropTerminal from the Altair directory, edit COM port if necessary, and minimize it.
7) Start 'altair_sim_25.spin' with F10 and when uploaded, restore PropTerminal quickly (click in the Taskbar).
8) use CP/M and have fun...
Andy
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Links to other interesting threads:
· Prop Tools under Development or Completed (Index)
· Emulators (Micros eg Altair, and Terminals eg VT100) - index
· Search the Propeller forums (via Google)
My cruising website is: ·www.bluemagic.biz
I could go to an 18K CP/M but unless anyone is desperate I'm going down to 16K which will make room for PropComm for it's VT100 emulation.
I had wondered about that idea of burying the disk image in a DOS file system while not actually using FAT code in the emulator. At the time I could not be sure the file would always be contiguous and I had no card reader anyway, still don't.
Now that I want to add simulated hard disks, 4 times 8Mbytes, this trick becomes very important. Time for me to get a card reader.
Ariba could you extend this to handle up to 8 floppy disk images and 4 hard disks, say: fd_a.dsk, fd_b.dsk ... fd_h.dsk, hd_i.dsk ... hd_l.dsk?
Cluso, waiting with great anticipation. There is no place to put external RAM driver code in PropAltair, I have to get on with multi COG emulator.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
For me, the past is not over yet.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Links to other interesting threads:
· Prop Tools under Development or Completed (Index)
· Emulators (Micros eg Altair, and Terminals eg VT100) - index
· Search the Propeller forums (via Google)
My cruising website is: ·www.bluemagic.biz
1. Upgrade to an 8080 only version of the ZiCog emulation. The accurate 8080 emulation will be called iCog.
2. Hardware will no doubt be Cluso's TriBlade board.
3. The big missing piece - The Altair front panel with all the switches and blinken lights !
Fortunately the TriBlade has a third Prop free to drive item 3.
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For me, the past is not over yet.
Leon
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Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle
I, probably more than most, am still nursing the beleif that because I could do Z80 machine code it made me an expert. It was true back in the 70's, but not now, Hey-Ho. Rest assured I bow to the efforts shown on these projects, they might make it possible for me, to appear, to know something about someting, again.
You are right "Upgrade to an 8080..." does not make much sense to the uninitiated. Thing is the ZiCog emulator is faster than my old 8080 only PropAltair emulator code. It is a more accurate emulation concerning flag setting. It is also a lot easier to understand and modify, for use with external RAM for example. So it is actually an upgrade in this context.
Anyway, it is not clear to me that moving to the Z80 instruction set on real silicon was much of an upgrade, only a few of the instructions gained you any speed. Most people seemed to realize that and kept away from 99% of the Z80 ops. The chip itself was faster and easier to integrate into systems though.
Never underestimate the power of an abacus. Needs no batteries, has non-volatile store, intuitive "What You See Is What You Get" interface. I can calculate square roots on an abacus.
For sure if you know Z80 assembler you are an "expert". That knowledge and understanding is transferable to pretty much all assembly languages, they are still in use today. It's a step toward becoming a compiler writer, an OS kernel writer.... The bounds are limitless.
@kwinnn
"schematic capture and PCB layout" What ? How? Id like to see the software that did that.
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For me, the past is not over yet.
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Links to other interesting threads:
· Home of the MultiBladeProps: TriBladeProp, SixBladeProp, website (Multiple propeller pcbs)
· 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)
· Search the Propeller forums (via Google)
My cruising website is: ·www.bluemagic.biz·· MultiBladeProp is: www.bluemagic.biz/cluso.htm
Leon
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Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle
http://forums.parallax.com/showthread.php?p=711157
Little did he know what we would be up to with it over thirty years later.
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For me, the past is not over yet.
Post Edited (heater) : 4/2/2010 4:10:28 PM GMT
Too bad this post went pretty much unoticed.·My Dad bought·Altair 8800 serial #175 and he and I soldered it up in 1975. The best father/son project I ever worked on.
I keeped it with me though many moves, but sold it on ebay in 2001. Still miss it, but it brought $3,500 when I·needed money.·Cost was $385.00 in 1975, if I recall, the 8080 CPU was about $175.00 of the cost.
Dr. Roberts was a unsung hero in my book.