Commodore Colt (PC10-III/PC20-III)

[SpidersWeb]

All of my PC-10 era Commodore's arrived still with the original warning sticker still covering the Mouse port (warning sticker not to plug in RS232 mice).
I imagine if you had an Amiga mouse, you probably had an Amiga, so I expect a rarely used feature.

 

[KenEG]

I discovered last night that the version of speed.exe that I have only supports the -s and -t switches. To get 9.54 MHz, I have to use the Ctrl-Alt-D key combination. Does anyone know if there is a version of speed.exe that supports the -d switch? If so, where can I get it from?

 

[Scali]

I discovered last night that the version of speed.exe that I have only supports the -s and -t switches. To get 9.54 MHz, I have to use the Ctrl-Alt-D key combination. Does anyone know if there is a version of speed.exe that supports the -d switch? If so, where can I get it from?

Pretty sure there is. I had speed -d in my autoexec.bat, so it always ran at full speed.
I've attached some utils I downloaded some time ago, it contains v1.2, which supports -std.

 

[KenEG]

If I type speed with no parameters, mine says it is version 1.2 c. Usage: SPEED -[st]. When I typed speed -d I got an invalid parameter message. I will try downloading what you attached and see if it is different.

 

[Flamin Joe]

I don't think they did. The mouse wasn't a very popular item back then. Windows wasn't 'a thing' yet, and most DOS applications didn't support it.
Silly enough, we didn't know this when we bought our first mouse, so we bought a Genius serial mouse, instead of an Amiga mouse.
When I got an Amiga later, I tried its mouse, on the PC10-III and found that it worked great.

Yes, I bought my Colt new. It didn't come with a mouse and I don't think I ever had one until I got my first Windows 3.1 machine. Just not very useful in that era.

Yes that makes sense didn't think of that. It was a bit different for the Atari's as they came with GEM Desktop so there was at least a GUI to use, just not very useful with the limited applications!

 

[Scali]

Yes that makes sense didn't think of that. It was a bit different for the Atari's as they came with GEM Desktop so there was at least a GUI to use, just not very useful with the limited applications!

Yea, and the reason they included GEM on their PCs is probably because they also used GEM on their ST line.
Commodore had their own WorkBench on the Amiga, which couldn't be ported to PC. And they didn't include Windows. GeoWorks would have been somewhat appropriate as well, given GEOS on C64 and C128, but I don't think the PC version existed yet.
I know some PCs from the late 80s to early 90s actually did include a copy of both DOS and Windows. Some Tulips did. Then again, they were aimed at office use, not home use.

 

[PhilipA]

Brings back memories. Our first computer was a PC20-III, with an ATi EGA Wonder card in, Philips color EGA monitor, Amiga mouse and the Commodore PC keyboard. My father spent a fairly large sum of money back then and got an 8087 for it and used it for CAD. Boy, was that ever slow. Hooked up to our Star LC24-200 color dot matrix printer, it would sometimes print what you had drawn...

I found that sometimes, if I did Ctrl-Alt-D at the point the computer had just done floppy seek at boot and did speaker test (four warbling bleeps?) It would sometimes run about twice as fast as normal under Ctrl-Alt-D. No idea why.

Phil

 

[sergey]

I discovered last night that the version of speed.exe that I have only supports the -s and -t switches. To get 9.54 MHz, I have to use the Ctrl-Alt-D key combination. Does anyone know if there is a version of speed.exe that supports the -d switch? If so, where can I get it from?

If you want to do it a really hackish way, you can create your own utility
Something like:

 

[KenEG]

Sergei...I might try that just for the fun of it. I had thought to look at speed.exe and the BIOS code for the Ctrl-Alt key combinations and figure out how to add a -d parameter to speed.exe. Thanks for your code. I assume numbers other than 81 evoke the other speeds. Do you know what they are? It might be fun to have 3 programs. Slow, turbo, and double.

 

[KenEG]

Pretty sure there is. I had speed -d in my autoexec.bat, so it always ran at full speed.
I've attached some utils I downloaded some time ago, it contains v1.2, which supports -std.

Yes, your version just shows version 1.2 with no letter after it, but it supports the -d parameter. Thanks! I know what set lock does, but can you tell me what the other utilities do?

 

[sergey]

I assume numbers other than 81 evoke the other speeds. Do you know what they are? It might be fun to have 3 programs. Slow, turbo, and double.

Your assumption is correct. Use the following values:
81 - 9.54 MHz
41 - 7.15 MHz
01 - 4.77 MHz
Actually only bits 6 and 7 control the CPU clock frequency. The rest are various other configuration settings. See the Configuration Register description in my FE2010A document.

 

[KenEG]

Your assumption is correct. Use the following values:
81 - 9.54 MHz
41 - 7.15 MHz
01 - 4.77 MHz
Actually only bits 6 and 7 control the CPU clock frequency. The rest are various other configuration settings. See the Configuration Register description in my FE2010A document.

Very nice. Thanks for the info and link.

 

[Scali]

Yes, your version just shows version 1.2 with no letter after it, but it supports the -d parameter. Thanks!

Interesting... I wonder where your utility came from then, and for what machine it was meant.
Reading sergey's info, apparently if the FE2010A is connected to a 14 MHz crystal, it only supports 4.77 and 7.15 MHz. So there may be some machines like that.

I know what set lock does, but can you tell me what the other utilities do?

One appears to be a keyboard driver for a Spanish keyboard.
The other seems to be a Spanish tool for partitioning harddrives.

 

[Scali]

Actually only bits 6 and 7 control the CPU clock frequency. The rest are various other configuration settings. See the Configuration Register description in my FE2010A document.

Interesting, so the chipset can run with zero-waitstate even at the higher clockspeeds.
I wonder if you could just replace the memory chips on the board with faster ones, to create a working zero-waitstate machine at 9.54 MHz.
It'd be considerably faster I think.

 

[KenEG]

Interesting, so the chipset can run with zero-waitstate even at the higher clockspeeds.
I wonder if you could just replace the memory chips on the board with faster ones, to create a working zero-waitstate machine at 9.54 MHz.
It'd be considerably faster I think.

I want to look at speed.exe sometime and see what it does. Like, does it change wait states depending on CPU clock? If so, faster ram and rewriting speed.exe may get you a faster machine. I am quite happy with what I have now. When I need something faster I will fix my 286 or use my 386/33.

 

[sergey]

Interesting, so the chipset can run with zero-waitstate even at the higher clockspeeds.
I wonder if you could just replace the memory chips on the board with faster ones, to create a working zero-waitstate machine at 9.54 MHz.
It'd be considerably faster I think.

The on-board memory always runs without wait states. The configuration register allows turning off wait states for the memory above 640 KiB. I tried doing that, and apparently the video memory of the VGA cards I've used is not fast enough, and it resulted in corrupted image (e.g. missing characters on display).

 

[sergey]

Reading sergey's info, apparently if the FE2010A is connected to a 14 MHz crystal, it only supports 4.77 and 7.15 MHz. So there may be some machines like that.

Intel Wildcard 88 modules without "-10" suffix in the model name have 14.81313 MHz crystal and only support 7.15 MHz turbo mode. Some of these modules were used in Leading Edge Model D computers.

 

[Scali]

The on-board memory always runs without wait states. The configuration register allows turning off wait states for the memory above 640 KiB. I tried doing that, and apparently the video memory of the VGA cards I've used is not fast enough, and it resulted in corrupted image (e.g. missing characters on display).

Oh I see, the 'memory bus' waitstates are only for memory beyond 640k?
Right... It'd be interesting to experiment with that. Perhaps a fast ET4000 card or such can run at zero waitstate
I have a Paradise VGA card in mine currently, and always found the graphics somewhat sluggish. But if it runs with 4 waitstates, that explains it.

 

[KenEG]

Sorry if this is a dumb question, but is this maybe due to the slower clock of the ISA bus? I think that always works at 4.77 MHz and some other overhead may make the wait states necessary for anything using the ISA slots. I am just trying to learn more, so don't be shy about correcting any erroneous information I throw out.

 

[Scali]

Sorry if this is a dumb question, but is this maybe due to the slower clock of the ISA bus? I think that always works at 4.77 MHz and some other overhead may make the wait states necessary for anything using the ISA slots. I am just trying to learn more, so don't be shy about correcting any erroneous information I throw out.

Well, I suppose that's the big question
There wasn't really a standard for ISA bus clock speed in the early days. It ran at 4.77 MHz de facto on the IBM PC and early clones/derivatives, since it was connected synchronously to the CPU.
When the AT came round, it would run on 6 MHz, and later on 8 MHz, because they used 6 and 8 MHz 286 CPUs respectively, still synchronously.

When even faster ATs came around, it became obvious that many ISA cards had trouble, because they were never designed for such speeds.
Eventually the maximum speed of ISA was set to 8.33 MHz on most machines (the 'accepted maximum speed', see http://www.pcguide.com/ref/mbsys/bios/set/advchISA-c.html), and it was connected with an asynchronous buffered bus.
Various chipsets allowed you to change the ISA bus speed via some dividers to get more performance at your own risk.

But what the speed of the bus is in 8088 'Turbo XT' class machines? I have no idea really. I would suspect that they'd err on the safe side and leave it at 4.77 MHz.
I'm pretty sure the PC10-III does not run it at 9.54 MHz, else you'd probably have issues with many cards.