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PC/XT Parallel Port Zip Drive Performance

G

Great Hierophant

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I am strongly considering using a Zip 100 drive with the palmzip driver for "mass" storage on my (whenever-it-gets-here) IBM PC 5150. The parallel port will be a unidirectional one. What kind of performance can I expect from such a setup? Would it be faster than a 360K floppy drive? Would modifying the parallel card to be bidirectional be worth it? Would it be feasible to run smaller games from the disk?
 
Great Hierophant said:
I am strongly considering using a Zip 100 drive with the palmzip driver for "mass" storage on my (whenever-it-gets-here) IBM PC 5150. The parallel port will be a unidirectional one. What kind of performance can I expect from such a setup? Would it be faster than a 360K floppy drive? Would modifying the parallel card to be bidirectional be worth it? Would it be feasible to run smaller games from the disk?
Click to expand...

Since IOMEGA never came out with 808x drivers for the parallel-port ZIP, you will have to buy the palmzip drivers to use it (they're very cheap). A bidirectional parallel port will let you exceed floppy drive times; without it, you will equal or be slightly under floppy drive times.
 
I've got it working on my IBM XT, with normal iomega drivers (5.2).
No need for the palmzip ones.

You do need at least DOS 5.0

The Zip-250 parallel I use is as fast or faster than the harddisk, to my feeling.
It certainly can replace a harddisk.

The original parallel ports (on a MDA card) might not work well, I use a separate I/O card.
 
http://www.brutman.com/forums/viewtopic.php?f=1&t=38

These posts give the relative speed of the Zip drives in a parallel port unidirectional/bidirectional.

So, you have successfully used an Iomega Zip 250 drive on an IBM PC/XT with MS-DOS 5.0 and the 5.2 driver. I have two questions:

1. How much conventional memory does MS-DOS 5.0 require in total to support the Iomega driver and itself?

2. Is your I/O card bidirectional, and does it support EPP and/or ECP?
 
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EPP is unbelievably good compared to bi-directional. EPP lets the hardware do more of the handshaking when transfering bytes, which dramatically improves the throughput over the software only method used on standard and bi-directional parallel ports.

I had not run it with a Zip drive, but when I measured the performance of a SCSI hard disk and SCSI adapter on a parallel port on a EPP port, it was about 3x faster than on the standard bi-directional port. (The test machine was a PCjr with a NEC V20.)
 
Jorg said:
I've got it working on my IBM XT, with normal iomega drivers (5.2).
No need for the palmzip ones.
Click to expand...

Seeing as I have NEVER gotten this to work, can you make your entire GUEST directory (ie. the guest.exe, the .ini, and all other files) available somewhere so I can download what you have and test? I keep getting conflicting reports that it does/doesn't work on an XT. If it does, it would make my life a hell of a lot easier...
 
Trixter said:
Seeing as I have NEVER gotten this to work, can you make your entire GUEST directory (ie. the guest.exe, the .ini, and all other files) available somewhere so I can download what you have and test? I keep getting conflicting reports that it does/doesn't work on an XT. If it does, it would make my life a hell of a lot easier...
Click to expand...

I'll try and dig it out- its a bit cold in the attic at the moment.

Most headache gave me the fact that it did not work with every parallel port, and the fact that it really needs DOS 4.0 or guest.exe won't give a drive letter out.

See here too: http://www.vintage-computer.com/vcforum/showpost.php?p=68131&postcount=49

BTW, I tried palmzip, but that only works with ZIP100's not with ZIP250's.
 
I was never able to get GUEST to work on my XT with my ZIP 100MB
drive. And I tried MANY different versions of the GUEST software.

I think there are different model/versions of the ZIP 100MB and
some may work while others may not. PALMZIP however works great :)
 
...except that palmzip is slower than guest, so I hope Jorg has the opportunity to brave the attic cold to get at that software :) (Remember, let electronics warm up to room temperature before turning them on!)
 
Trixter said:
...except that palmzip is slower than guest, so I hope Jorg has the opportunity to brave the attic cold to get at that software :) (Remember, let electronics warm up to room temperature before turning them on!)
Click to expand...

palmzip was much faster than guest on my XT :)
 
Well now I'm 100% confused.

The last time I tried to use a .zip drive was with a FAT-16 capable DOS (DRDOS 7.03), a bidirectional LPT, and an NEC V30 chip. I had no luck.

I guess I'll have to drag out all my hardware to figure out what's going on.
 
One nice thing I noticed about the zip drive , its recognized by
Windows 98 without even installing guest.exe. After dumping
all the files from my XT/AT onto the zip drive I was able to attach
the zip drive to my Win98 machine and burn everything onto a CD.
 
Can a SCSI zip drive be made to work in a PC/XT with an 8-bit SCSI controller card inside? I would imagine that the transfer rates would be much faster, if there is a version of guest.exe that will work.
 
A SCSI Zip will work on a SCSI card in an XT. You need a decent SCSI card with an ASPI compatible driver.

Performance will probably be better than on the parallel port because SCSI is a much better bus interface than a parallel port is.
 
mbbrutman said:
A SCSI Zip will work on a SCSI card in an XT. You need a decent SCSI card with an ASPI compatible driver.

Performance will probably be better than on the parallel port because SCSI is a much better bus interface than a parallel port is.
Click to expand...

Of course, many other SCSI devices will work as well.

I believe an ASPI compatible driver would be a something like ASPI4DOS.SYS, but what is a decent SCSI card? One with an Adaptec SCSI interface?
 
Doesn't matter too much--I have a soft spot for DTC 8-bit SCSI adapters, but Trantor/Adaptec is fine as are a host of others--as long as you can find either an ASPI or MCAM driver for it.

If you want to confuse matters further, try using a parallel-port SCSI adapter, like an Adaptec MA358... :)
 
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