Tape and disk loading speed on 8 bit computers

[Troper]

Which 8 bit computer has the fastest and slowest tape loading and disk drive?

[potatohead]

Which 8 bit computer has the fastest and slowest tape loading and disk drive?

 

IMHO Apple and Atari have the slowest cassette. I think Tandy CoCo has the fastest, and most robust cassette. 1200bps + filename support

[JamesD]

Which 8 bit computer has the fastest and slowest tape loading and disk drive?

 

IMHO Apple and Atari have the slowest cassette. I think Tandy CoCo has the fastest, and most robust cassette. 1200bps + filename support

The CoCo is 1500 baud. There might be some oddball machines that are a little faster.

The Model 1 is something like 250 baud for Level 1 BASIC and 500 for Level 2 BASIC.

The Apple II was 1200 baud.

 

There are some fastloaders for the Spectrum that are crazy fast but they aren't standard.

[JamesD]

MSX appears to offer 1200 or 2400 baud modes.

[potatohead]

Thanks on CoCo, I always screw that up. Don't know why. 2400 on tape for MSX is pretty sweet actually. Never knew that. Do MSX machines do file-names, and actually use them, like skip over the wrong one kind of use them?

[Kalvan]

Thanks on CoCo, I always screw that up. Don't know why. 2400 on tape for MSX is pretty sweet actually. Never knew that. Do MSX machines do file-names, and actually use them, like skip over the wrong one kind of use them?

 

They do file names, they do extensions. About the only thing they can't do (until Turbo R, which by that time wasn't 8 bit anymore) is separate subdirectories.

[Rybags]

Commodore tape was pretty slow, although it stored the data twice.

 

I'm fairly sure there were some systems that used 300 baud for tapes, although I think at least one of those systems had the option to use higher speeds.

 

The Compucolor II, which was also supposedly the first consumer colour system in 1977 had an abysmally slow disk drive, although old-computers has it listed as doing 76.8 kilobits/second.

The resultant speed was slow though because of the filing system - it moved data around when saving, supposedly because it was a reworked tape operating system.

 

That aside, the Compucolour probably had the lowest capacity floppy drive - all of around 53K. It also had a buggy OS/Basic. If you pressed a key during certain operations, it'd cause screen corruption and all sorts of other weird stuff to happen. For a couple of years, it was the only computer at the High School I went to.

[+Stephen]

The Atari tapes were slow at 600 baud. The stock disk drives were 19,200 baud, but 57,600 was possible (which gave a 3kByte/sec transfer). The biggest problem with the Atari disk drives was the serial interface. The parallel bus on that machine can easily handle 70k/sec transfers.

 

Stephen Anderson

[JamesD]

Thanks on CoCo, I always screw that up. Don't know why. 2400 on tape for MSX is pretty sweet actually. Never knew that. Do MSX machines do file-names, and actually use them, like skip over the wrong one kind of use them?

 

They do file names, they do extensions. About the only thing they can't do (until Turbo R, which by that time wasn't 8 bit anymore) is separate subdirectories.

I thought the Turbo R was still 8 bit but a piplined RISC core to implement the Z80 and it still runs the old code only faster.

I have a Turbo R machine but no software... not that works anyway. That or the floppy drive is bad.

 

I know with double speed mode the CoCo could do high speed saves and loads but you needed to do some pokes before the load in order for the timing to be correct. It wasn't useful from a commercial standpoint but I tried it and it worked. There was an article on it in Rainbow Magazine if I remember right. I'm not sure what the final baud rate was though. Double speed implies 3000 but I think it worked out to a little less because double speed was only in effect while accessing ROM.

 

CoCo floppies were parallel so they were pretty fast but I don't know the exact speed. They stored around 150K if I remember right.

 

Apple floppies were parallel as well. Capacity varied by DOS version. 113K for earlier versions, 140K for later versions. Later controllers supported 3.5" 800K drives and one controller even supported the high density disks but I think it's pretty rare.

[Troper]

How was the MSX tape speed switchable between 1200 and 2400 baud?

[JamesD]

How was the MSX tape speed switchable between 1200 and 2400 baud?

I have no idea. There must be a command or POKE to do it. Tape interfaces are just software with timing loops and hardware just converts to/from analog sound. As long as the analog parts can handle the speed you can drive it as fast as the CPU will go. No guarantee the tape deck or tape media can handle greater speeds. Tape noise really limits what you can do.

 

Now, thanks to digital media, we can generate tape programs that start with a small high speed loader that then loads the rest of the program as fast as we can drive the hardware on a given machine.

[Kalvan]

Thanks on CoCo, I always screw that up. Don't know why. 2400 on tape for MSX is pretty sweet actually. Never knew that. Do MSX machines do file-names, and actually use them, like skip over the wrong one kind of use them?

 

They do file names, they do extensions. About the only thing they can't do (until Turbo R, which by that time wasn't 8 bit anymore) is separate subdirectories.

I thought the Turbo R was still 8 bit but a piplined RISC core to implement the Z80 and it still runs the old code only faster.

I have a Turbo R machine but no software... not that works anyway. That or the floppy drive is bad.

 

You lucky dog you! And the Ascii R800 was indeed a 16 bit chip, essentially a RISC inplimentation of a Zilog Z800/280.

Edited January 1, 2010 by Kalvan

[Kalvan]

I thought the Turbo R was still 8 bit but a piplined RISC core to implement the Z80 and it still runs the old code only faster.

I have a Turbo R machine but no software... not that works anyway. That or the floppy drive is bad.

 

You lucky dog you! And the Ascii R800 was indeed a 16 bit chip, essentially a RISC inplimentation of a Zilog Z800/280.

 

I think there are some SCSI interface cards/cartridges out there. If you can find one, you can hook it up to s (narrow) SCSI disc drive.

 

Oh, and www.gamesx.com has an article on replacing the disc drive.

Edited January 1, 2010 by Kalvan

[JamesD]

I think there are some SCSI interface cards/cartridges out there. If you can find one, you can hook it up to s (narrow) SCSI disc drive.

 

Oh, and www.gamesx.com has an article on replacing the disc drive.

Actually, someone designed a Compact Flash or SD card interface... can't remember where I saw it though.

[desiv]

I don't know how fast, but I'd be willing to bet that the Adam Digital Data Pack was the fastest cassette tape drive on an 8-bit.

 

desiv

Edited January 1, 2010 by desiv

[JamesD]

I don't know how fast, but I'd be willing to bet that the Adam Digital Data Pack was the fastest cassette tape drive on an 8-bit.

They are 19.2K but not standard cassette tapes.

 

The Spectrum loads at 1350 baud from cassette tapes but I couldn't find microdrive load speed.

Since they were saying 10 seconds average load or save time and the carts hold around 85K I'm guessing pretty fast.

[JamesD]

I know with double speed mode the CoCo could do high speed saves and loads but you needed to do some pokes before the load in order for the timing to be correct. It wasn't useful from a commercial standpoint but I tried it and it worked. There was an article on it in Rainbow Magazine if I remember right. I'm not sure what the final baud rate was though. Double speed implies 3000 but I think it worked out to a little less because double speed was only in effect while accessing ROM.

February 1986 issue of Rainbow Magazine, PP.76-77

 

To save at high speed, use:

POKE 65495,0

Then save your program as you normally would.

 

To load a program saved in high speed:

POKE 65495,0 : POKE 143,15 : POKE 144,20 : POKE 145,7

Then load as you normally would.

 

To return the machine and cassette to normal speed:

POKE 65494,0 : POKE 143,18 : POKE 144,24 : POKE 145,10

 

That's just the first values the article gives to try.

It says to try POKE 146,1 (or more) before you record to increase the length of leader tape sent at the start of each block if you have problems

 

Find and read the article for full details.

High speed tapes should be at about 3000 baud since the save routines don't access RAM much.

[Herbarius]

February 1986 issue of Rainbow Magazine, PP.76-77

 

To save at high speed, use:

POKE 65495,0

Then save your program as you normally would.

 

To load a program saved in high speed:

POKE 65495,0 : POKE 143,15 : POKE 144,20 : POKE 145,7

Then load as you normally would.

 

To return the machine and cassette to normal speed:

POKE 65494,0 : POKE 143,18 : POKE 144,24 : POKE 145,10

 

That's just the first values the article gives to try.

It says to try POKE 146,1 (or more) before you record to increase the length of leader tape sent at the start of each block if you have problems

 

Find and read the article for full details.

High speed tapes should be at about 3000 baud since the save routines don't access RAM much.

 

Can you do something like this on the C64?

[Rybags]

Not that I know of ... although there might be a way to get it to only load the first copy of a saved program.

 

I've got a commercial version of the Pavloda mastering system here (turbotape).

I transferred it with an XM1541, problem is though that it has a couple of bad sectors. AFAIK it's corruption and not a copy-protection scheme, so I don't know if it'll work properly.

[JamesD]

February 1986 issue of Rainbow Magazine, PP.76-77

 

To save at high speed, use:

POKE 65495,0

Then save your program as you normally would.

 

To load a program saved in high speed:

POKE 65495,0 : POKE 143,15 : POKE 144,20 : POKE 145,7

Then load as you normally would.

 

To return the machine and cassette to normal speed:

POKE 65494,0 : POKE 143,18 : POKE 144,24 : POKE 145,10

 

That's just the first values the article gives to try.

It says to try POKE 146,1 (or more) before you record to increase the length of leader tape sent at the start of each block if you have problems

 

Find and read the article for full details.

High speed tapes should be at about 3000 baud since the save routines don't access RAM much.

 

Can you do something like this on the C64?

The CoCo series has a double clock speed mode that can be enabled with a poke (high speed = POKE 65495,0 low speed = POKE 65494,0). It causes the CPU to run at double speed when accessing ROM. That makes BASIC run faster and as a result, CSAVE and CSAVEM save at double speed very easily.

The other pokes are to RAM variables the ROM uses for timing with tape commands. Those only need tweaking because the load routine accesses the RAM more than save routine and RAM access is half as fast as ROM access and the load timing is a little off with normal values.

I suppose you could modify the same parameters on save so you could just enter high speed mode before loading. That would actually be easier for users if you wanted to distribute a file/cassette recorded in high speed mode.

 

But I digress...

The C64 has no such high speed mode and I don't know if it has similar variables in RAM.

In other words, no. At least not as easily. You would need new high speed save and load routines.

[Herbarius]

Thanks for the quick answer, JamesD, even if it was a little disappointing to hear that I really could have used something like that.

 

 

I just thought maybe the speed of normal loading and saving with tapes on the C64 might be lower than what the hardware actually could handle - maybe for reasons of better reliability.

 

After all, the C64 does control the tape motor, but I don't know whether it can control the speed as well.

[JamesD]

Thanks for the quick answer, JamesD, even if it was a little disappointing to hear that I really could have used something like that.

 

 

I just thought maybe the speed of normal loading and saving with tapes on the C64 might be lower than what the hardware actually could handle - maybe for reasons of better reliability.

 

After all, the C64 does control the tape motor, but I don't know whether it can control the speed as well.

Actually, the hardware is capable of much faster speeds. You just need need routines that drive it faster.

There are fast loader routines out there for some machines. You need a program that saves the loader to tape at normal speed and then the program at high speed. The small loader loads at normal speed, autostarts, then loads the program at high speed. I believe the program Rybags is talking about is supposed to do this.

 

An added possibility is to compress the program as well. Then the loader loads at high speed and decompresses the program. This results in an even shorter load time. So, you are combining a fast loader with a packer.

 

There is a video on youtube of a Spectrum loading at 27428 baud even though it is normally way slower.

http://www.youtube.com/watch?v=-BAHjRsnNWA

[vcsdream]

Spectrum games always loaded fast, not much to load really....no sound needed, monochrome graphics, joystick routines not needed....not much game to start off with.

[Herbarius]

Yes, thanks again JamesD. I will look into it, but from the sound of it its too complicated for my purposes.

 

EDIT: Found "Multi-Tape" and "Supertape", I will see if I'll use it... Depends on how big my small program actually will become when it's finished, of course it'll only be worth it, if it's significantly bigger than the fast-loader itself

Edited January 3, 2010 by Herbarius

[Seob]

February 1986 issue of Rainbow Magazine, PP.76-77

 

To save at high speed, use:

POKE 65495,0

Then save your program as you normally would.

 

To load a program saved in high speed:

POKE 65495,0 : POKE 143,15 : POKE 144,20 : POKE 145,7

Then load as you normally would.

 

To return the machine and cassette to normal speed:

POKE 65494,0 : POKE 143,18 : POKE 144,24 : POKE 145,10

 

That's just the first values the article gives to try.

It says to try POKE 146,1 (or more) before you record to increase the length of leader tape sent at the start of each block if you have problems

 

Find and read the article for full details.

High speed tapes should be at about 3000 baud since the save routines don't access RAM much.

 

Can you do something like this on the C64?

There are a dozen or so fastloader carts for the c64, like the epyx fastload or the final cartridge III or KCS Power Cartridge or Expert cartridge.

 

I don't know how fast it is but i read that the microcassette in the Philips P2000 had a speed that was 10 times faster then the normal tapes. It also can display a listing of programs stored on tape, and automatic searches and starts the program when you load it.